From Occupy Wall Street to Black Lives Matter, calls for social justice have taken centre stage in political debate in the United States and, more broadly, in Western liberal democracies.

This raises a question: what is “social justice”, and what would a “just” society look like? There are long and complex debates about this. The left-wing thinker Slavoj Žižek once remarked that social justice activists often struggle to articulate what, exactly, a just society would be.

I am, of course, fundamentally anti-capitalist. But let’s not have any illusions here. No. What shocks me is that most of the critics of today’s capitalism feel even embarrassed, that's my experience, when you confront them with a simple question, “Okay, we heard your story . . . protest horrible, big banks depriving us of billions, hundreds, thousands of billions of common people's money. . . . Okay, but what do you really want? What should replace the system?” And then you get one big confusion. — Slavoj Žižek interview

In this post, I argue that the seemingly impenetrable layers of debate about social justice become much easier to make sense of through the contractualist approach of game theorist Ken Binmore.

What is social justice about?

Open almost any textbook on political philosophy, and you will find a long list of questions about justice at the level of society. Justice concerns how income and wealth are distributed, how social relationships are structured, how respect and social status are allocated, and how political power is distributed and constrained. It is not always clear which of these questions matters most.

There is also no shortage of answers. Some theories argue that society must protect individual rights. Others say that happiness is what matters. Others claim that objective outcomes matter more than subjective satisfaction, so what must be allocated justly is resources. Still others add that resources are not enough, because we also need to ask what people can actually do with them.

As you read, you quickly meet a familiar list of dilemmas without clear answers. Should society protect liberty or ensure equality? Should institutions prioritise economic efficiency or fairness through redistribution? Should society focus on improving the situation of the worst-off, or on rewarding those whose effort and talent contribute most to innovation and wealth creation?

If you end up confused, that is not surprising. The paradox of social justice is that we share many intuitions about it without sharing a clear and coherent intellectual framework for thinking about it.

One theory, however, does provide such a unifying framework. In two books published in 1994 and 1998, Ken Binmore makes a kind of Copernican move in political philosophy. Most approaches assume that there is some independent justice “out there”, and that the task of political philosophy is to discover the just answer to questions such as liberty or equality, or efficiency or redistribution. Binmore reverses the perspective. Fairness is not something we discover. It is a social solution to pervasive bargaining problems: who should do what, and who should get what, in society. The result of this bargaining is a social contract, and what we call “fair” is what respects that contract.

Binmore’s starting point is that social interactions are primarily characterised by cooperation. This is easy to overlook because we tend to notice failures of cooperation rather than its constant presence in everyday life. Yet social cooperation—from not running away from a café without paying to having a product made on the other side of the world delivered to your doorstep—generates benefits. The key question is therefore how to divide those benefits, as well as the work required to produce them. An agreement about how to cooperate, the rules needed to sustain cooperation, and the way the gains from cooperation are shared are a social contract.1

It is common to represent this problem with the picture below. By cooperating, Alice and Bob can get benefits. A social contract organises their cooperation and determines both the benefits and their splits. Some social contracts leave some potential benefits untapped: either Alice, or Bob, or both could get more with a better agreement. A pattern of cooperation is efficient when it is not possible to improve the outcome of anybody anymore without making some people worse off. In short, a social contract is efficient when it does not leave any money on the table. There are typically many efficient social contracts.2

One possible way of organising social life would be to haggle all the time. But haggling is costly. It would take time and effort all day, from deciding who speaks first in a meeting to deciding what to watch on television at home.

Because haggling is costly, it makes sense for social groups to develop conventions that smooth such conflicts by aligning expectations around commonly accepted ways of allocating rights and duties. These conventions are fairness norms. They guide us towards what everybody agrees is the “right” thing to do. They are common knowledge: we know them, we know that others know them, and we know that others know that we know them. When we make a “fair” offer, we do so knowing that it fits an accepted norm, and knowing that the other person knows that too.

These fairness norms shape social interactions of all kinds, from how long we can speak in a discussion without sounding overbearing to how much of a pay rise we can reasonably ask for after a run of good performance. They may seem invisible because they are typically voiced explicitly only when they are violated. At a cinema, for example, everybody may quietly queue according to a “first come, first served” norm. The norm is stated out loud only when someone breaks it, and another person says, “We were here first.”

Binmore thinks that our moral sense and our psychology of fairness judgements evolved to solve bargaining problems in the relatively small-scale social environments of tribes and villages. We now use those same cognitive tools when we think about social justice in large societies. Sometimes our intuitions are ill-suited to that scale and can mislead us. Even so, Binmore thinks we can build on that psychological apparatus, and on a better understanding of it, to construct social contracts that work in large-scale societies.

Answers to classical questions about social justice

Individual rights vs social goals

A major question in political philosophy is how strongly individual rights should be protected, and when society may fairly ask individuals to sacrifice their own interests for collective goals. At one end of the spectrum are those who treat individual rights as sacrosanct. At the other end are those who think personal interests should largely efface themselves in the pursuit of a better society. In Binmore’s contractualist and naturalist perspective, both extremes are misguided.

The full subordination of individual interests to collective goals cannot work as a sustainable social contract. The idea that, in a good society, people would fully sacrifice their personal interests to the collective has appeared repeatedly in both religious and political ideologies. Karl Marx famously described a socialist society as one where everyone's endeavours would be to contribute to society and make it just.

From each according to his ability, to each according to his needs! — Marx (1875)

Unfortunately, such a vision is poorly suited to a social contract among human beings. Humans are only imperfectly related genetically and have typically no desire to sacrifice themselves completely for others. They will therefore resist a fully collectivist social contract. As E.O. Wilson famously remarked about communism: “Good ideology. Wrong species.” Communism would be much better suited to a society of clones, or near-clones, like ants.3

Given the imperfect alignment of interests within human society, such a philosophy is bound to fail. As Binmore ironically points out, it would encourage people to exaggerate their needs and understate their abilities, to the detriment of social outcomes.

In the socialist utopia that would ensue after the state had eventually withered away, the rule was to be: from each according to his ability—to each according to his need. Human nature being what it is, such an incentive scheme seems designed to convert the able of a large society into the needy overnight. — Binmore (1998)4

The misleading idea of a single common good. One of the mistakes behind the idea of the importance of social goals is even more fundamental. It is the idea that there is a well-defined common good to pursue. It is important to depart from such a commonly expressed view. There would be a unique common good only if we were clones. In that case, there would be a single efficient outcome under full cooperation, where all get the same payoffs because our interests would be perfectly aligned.5

But we are not clones. Our interests are not perfectly aligned, and humans care about how the benefits and costs are divided among themselves.

To say that there is no single common good is not to deny that society can be improved for everyone. When Alice and Bob move from disagreement to a social contract that gives both of them higher payoffs, they find a mutually beneficial arrangement. But their interests still diverge over which mutually beneficial arrangement to choose. Political debate is therefore partly about finding mutually advantageous improvements, but also, and often mainly, about finding an acceptable compromise among competing advantageous outcomes.

To tap into the benefits of cooperation, some constraining rules are required. The fact that people are unlikely to accept a full sacrifice of their interests does not mean that social contracts can be free of constraints on individuals. Working together requires some rules, some modus operandi, about who does what, who gets what and what the sanctions are for failing to respect these rules. People might be willing to accept such constraining rules because repeated interactions create potential mutual gains that align the interests of the members of a group: they have an incentive to make successful cooperation happen.

The agreed-upon rules of cooperation in a group define the rights of the group members. Rights are the actions allowed and the guarantees offered by the social contract. They are the product of the social contract. There are no mystical “rights” that predate the social contract.

Those who claim that “individual rights” pre-exist the social contract are therefore mixing things up. Of course, all else equal, people prefer fewer constraints and being allowed to do more things. They will generally prefer social contracts with more rights, in that sense. But they will also accept constraints when those constraints improve the outcome for all. Who would want to live in a society where everybody has the “right” to choose on which side of the road to drive?

As a metaphor, consider a group of people deciding the rules of a ball sport. May they carry the ball, as in rugby, or touch it only with their feet, as in football? Someone claiming that players have a pre-existing “right” to carry the ball would be missing the point. The issue is precisely to determine which rules will make the game work. What players will be allowed to do is the result of that decision. There is no prior right that already existed before any decision was made.

The idea of natural rights might seem appealing, but, as Jeremy Bentham famously put it, it is nonsense.

From this perspective, there is no real dilemma between individual rights and collective endeavour, because there are neither rights to defend in the abstract nor collective goals that stand above individuals’ interests. The whole opposition is misleading. A good social contract contains whatever rules are needed to make cooperation work for all, but no more than that.

Liberty vs equality

A related debate asks whether a society should aim primarily at liberty or at equality. This question takes on particular importance in modern societies. There is broad agreement on political rights (e.g. every adult should have the right to vote), but much less agreement on economic rights. Some defend leaving the outcomes of market interactions largely untouched. Others favour regulating markets and redistributing resources so that outcomes are more equal than those generated by market exchange alone.

Deontological defence of freedom and markets. For some free-market thinkers, such as philosopher Robert Nozick, it is a matter of principle that the state has no right to interfere with private property rights and the exchanges that follow from them. In the opening line of his book Anarchy, State, and Utopia, he writes:

Individuals have rights, and there are things no person or group may do to them (without violating their rights). — Nozick

But, as with natural rights more generally, the idea that property rights pre-exist the social contract does not make much sense. Property rights are social conventions backed by institutions. As 19th-century liberal thinker Benjamin Constant put it:

Property, to the extent it is a social convention, falls within the scope of political jurisdiction. — Constant (1815)6

So it is a mistake to claim that property rights cannot be touched. Property rights are an important part of a good social contract, but they are the result of that contract. Without police, courts, and a wider willingness to respect ownership, talk of “property rights” would be little more than talk. In a Wild West setting, property would be respected only to the extent that each owner could defend it by force.

Binmore insists that markets are not “natural”. They are part of the social contract:

[I]t seems obvious that the existence of a well-developed social contract is a precondition for the emergence of a market. — Binmore (1998)

Said simply, markets will work and their outcomes will be respected only if people are happy for it to be the case. Experiments in psychology have shown that in many situations, lay people find the “market price” that matches supply and demand unacceptable.

Market transactions are just one kind of social interaction. They do not enjoy a legitimacy that stands outside the social contract. They are accepted only if they fit within it. Nothing says that all market transactions, of every kind, ought to be accepted by everyone. People bring to markets social and moral preferences that were often shaped long before modern market societies existed.7 A social contract that ignored those preferences and relied blindly on market outcomes would not be sustainable, simply because people would disagree with it.

On the left, people often justify taxing the rich by saying that their wealth was created thanks to social institutions. That is not quite Binmore’s argument. Binmore’s point is simpler. Markets can function as mechanisms for allocating resources and organising production only if enough members of society agree to the social contract in which those markets operate. If market outcomes do not sufficiently benefit the worst-off, nothing compels them to keep supporting that arrangement. For the wealthy to enjoy large fortunes, they need enough poorer citizens not to overturn the system politically by, for instance, voting for a communist party. There are no mystical property rights that morally bind the poor not to expropriate the rich. Remember, it is all about social bargaining. It is about finding an acceptable compromise for all.

To prevent poor people from expropriating them, rich people might want to offer them a social contract that gives them a better deal. This was, in part, one historical function of the welfare state. Elites often supported social insurance not just out of benevolence, but also to reduce the appeal of revolutionary ideologies. Bismarck, the architect of the German welfare state, put it quite clearly:

My idea was to bribe the working classes, or shall I say to win them over, to regard the state as a social institution existing for their sake and interested in their welfare. — Bismarck

In that perspective, markets are neither to be worshipped nor despised. They are valuable because they tend to generate wealth, and because their decentralised character helps avoid the concentration of power associated with a politically administered economy. But their outcomes are not sacred.8

Consequentialist defence of economic freedom. A different argument for markets is simply that they tend to work better and therefore should be left relatively unconstrained. This is the line associated with economist Friedrich Hayek, for instance. Like most economists, I would agree, and I suspect Binmore would too, that Hayek was right about a great deal in his account of how markets coordinate decentralised information and organise production. But, again, like most economists, I would also say that he took too large a leap in assuming their broad superiority in all relevant circumstances. Markets may fail in many ways, and ensuring that they deliver good outcomes for consumers and producers often requires a lot of regulation.9

Defenders of markets are right, however, to reply that the risk of market failure does not by itself justify political intervention. There is no benevolent policy-maker standing above society. Public Choice theory has correctly emphasised that politicians and administrators pursue their own interests, and these are often at odds with those of the broader public. There is therefore no guarantee that state intervention will correct market failures rather than worsen them.

The sensible conclusion is not that markets are always right or that politics is always worse. It is that proposals for reform should be informed by both the strengths and the limitations of markets and representative democracy. In fact, the design of market rules and political institutions should be treated as a problem in mechanism design: how to structure the rules of the game so that, despite divergent interests, the resulting behaviour leads to good outcomes.

David Hume had anticipated this way of thinking:

When there offers, therefore, to our censure and examination, any plan of government, real or imaginary, where the power is distributed among several courts, and several orders of men, we should always consider the separate interest of each court, and each order; and, if we find that, by the skilful division of power, the interest must necessarily, in its operation, concur with the public, we may pronounce that government to be wise and happy. — Hume (1742, Of the independency of parliament)

Efficiency vs fairness

This is one of the most frequent dilemmas mentioned in political philosophy discussions. In his book, Equality and Efficiency. The Big Tradeoff (2015), economist Okun said

The contrasts among American families in living standards and in material wealth reflect a system of rewards and penalties that is intended to encourage effort and channel it into socially productive activity. To the extent that the system succeeds, it generates an efficient economy. But that pursuit of efficiency necessarily creates inequalities. And hence society faces a tradeoff between equality and efficiency. — Okun (2015)

Sometimes reducing inequality does indeed come at a cost. If inequality is generated by market incentives that encourage work, investment, or innovation, then reducing it may weaken those incentives. Taxing entrepreneurs more heavily may reduce the creation of products and services that benefit everyone.

Yet, from Binmore’s perspective, the standard fairness-versus-efficiency dilemma vanishes. The reason is that it rests on an ill-posed question: fair relative to what? For Binmore, fairness concerns how the gains from cooperation are shared. That immediately separates two issues. First, society should make cooperation as productive as possible and therefore consider only efficient social contracts. Second, among those efficient social contracts, society should choose one. That is where fairness comes in. Fairness norms are used to select one of the efficient social contracts.

Binmore spells out this point in that way:

It is true that people sometimes so focus on the question of how a cake is to be divided that they forget that it may be worse for everybody to divide a small cake equally than a large cake unequally, but such inefficiencies are not somehow inevitable when fairness criteria are applied. […] When fairness criteria are employed in the manner for which they evolved, they are used to select among the set of efficient equilibria. Efficiency therefore takes priority over equity. — Binmore (1994)

So there is no genuine conflict between fairness and efficiency if fairness is understood properly. The fairness question arises only when considering social contracts that are efficient. It would not make sense to consider social contracts that are not efficient.

To go back to Okun’s point, markets may create wealth, and reducing inequality may lead to less total wealth in society. But the most suitable social contract, in the sense of being the most likely to be accepted and sustained, is not the one that leads to the greatest wealth creation without regard for who benefits from it. If a social contract leads to a lot of wealth creation but all that wealth is concentrated at the top, those who are not at the top might instead argue for another efficient social contract that benefits them as well.10

People who defend the sacred nature of property rights might feel that people have no “right” to claim the wealth created by successful workers and entrepreneurs. But a social contract approach à la Binmore does not claim that people have, in principle, a “right” to the wealth created by others in society. It says something more fundamental. All the opportunities for wealth creation, and the rights to enjoy wealth privately, are the products of a social contract. Who gets what and how is part of the negotiation of that contract. There would be little reason for people to support a social contract that creates a lot of wealth if that wealth ends up concentrated only at the top.11

Binmore’s framework gives a rather different perspective on political debate. It is not that equality, liberty, or fairness are absolute principles that should guide political decisions. Instead, political debates about fair decisions need to look for mutually beneficial and sustainable solutions.

What is a just society, on this view? It is a society that abides by commonly accepted norms for solving bargaining questions about how to allocate rights and duties, and costs and benefits, across social life. Those accepted norms define what counts as “fair”. This also helps explain why it is often difficult to give a neat abstract definition of a just society. Our shared principles of justice are often embedded in practices and expectations rather than stated explicitly. They become visible mainly when they are violated.

That is one reason why social justice is typically—as stated by left-wing intellectual Nancy Fraser—experienced negatively, when our norms of fairness are violated.

[J]ustice is never actually experienced directly. By contrast, we do experience injustice, and it is only through this that we form an idea of justice. Only by pondering the character of what we consider unjust do we begin to get a sense of what would count as an alternative. Only when we contemplate what it would take to overcome injustice does our otherwise abstract concept of justice acquire any content. Thus, the answer to Socrates’s question, ‘What is justice?’ can only be this: justice is the overcoming of injustice. — Fraser (2012)

In addition, fairness norms are always partly renegotiated, as different social groups try to improve their position in the social contract, whether in wages, social status, or political recognition. Criticisms of “injustice” and calls to make society more “just” are often, in practice, attempts to move the needle of fairness norms in favour of some groups rather than others. When such movements succeed, society comes to accept a new answer to the question of what counts as just.

This also explains a key feature of political debate. Although politics is largely about the allocation of material resources and social recognition in the Game of Life, it is often conducted in the Game of Morals. Social groups and their representatives do not merely haggle over money and status directly. They argue about merit, need, dignity, and respect, because these are the moral categories through which claims to a larger share of social resources are made.

In the next post, I will look at what kind of fairness norms we actually adopt in society and why.

References

Bentham, J. (1843) ‘Anarchical fallacies’. In: Bowring, J. (ed.) The Works of Jeremy Bentham. Vol. 2. Edinburgh: William Tait.

Binmore, K. (1994) Game Theory and the Social Contract, Volume 1: Playing Fair. Cambridge, MA: MIT Press.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. Cambridge, MA: MIT Press.

Binmore, K. (2005) Natural Justice. New York: Oxford University Press.

Constant, B. (2003 [1815]) Principles of Politics Applicable to All Governments. Edited by E. Hofmann, translated by D. O’Keeffe. Indianapolis, IN: Liberty Fund.

Gaertner, W. and Schokkaert, E. (2012) Empirical Social Choice: Questionnaire-Experimental Studies on Distributive Justice. Cambridge: Cambridge University Press.

Genicot, G. and Ray, D. (2003) ‘Group formation in risk-sharing arrangements’, Review of Economic Studies, 70(1), pp. 87–113.

Harsanyi, J.C. (1955) ‘Cardinal welfare, individualistic ethics, and interpersonal comparisons of utility’, Journal of Political Economy, 63(4), pp. 309–321.

Harsanyi, J.C. (1975) ‘Can the maximin principle serve as a basis for morality? A critique of John Rawls’s theory’, American Political Science Review, 69(2), pp. 594–606.

Hayek, F.A. (1945) ‘The use of knowledge in society’, American Economic Review, 35(4), pp. 519–530.

Hayek, F.A. (1960) The Constitution of Liberty. Chicago: University of Chicago Press.

Hume, D. (1742) ‘Of the independency of parliament’. In: Essays, Moral and Political. Edinburgh: A. Kincaid.

Marx, K. (1875) ‘Critique of the Gotha Programme’. In: Marx, K. and Engels, F. Selected Works. Vol. 3. Moscow: Progress Publishers, pp. 13–30.

Nozick, R. (1974) Anarchy, State, and Utopia. New York: Basic Books.

Okun, A.M. (1975) Equality and Efficiency: The Big Tradeoff. Washington, DC: Brookings Institution.

Rawls, J. (1971) A Theory of Justice. Cambridge, MA: Belknap Press of Harvard University Press.

Schildberg-Hörisch, H., 2010. Is the veil of ignorance only a concept about risk? An experiment. Journal of Public Economics, 94(11-12), pp.1062-1066.

Schokkaert, E. and Tarroux, B. (2022) ‘Empirical research on ethical preferences: How popular is prioritarianism?’. In: Adler, M.D. and Norheim, O.F. (eds) Prioritarianism in Practice. Cambridge: Cambridge University Press, pp. 459–517.

The importance of fairness as a determinant of just solutions is a key aspect of human interactions. “It’s unfair!” is one claim children learn to say very early in life. And in adult political debates, claims about social injustice play a major role.

But how do we know what such statements about fairness mean? Open one of the many textbooks in moral and political philosophy, and you will be struck by the fact that there are huge debates between highly respectable and knowledgeable scholars about what makes something fair. Not only can we not assume that toddlers have an intellectual grasp of the issues raised in these textbooks, but most adults who discuss social justice would also struggle to define what they mean by the term.

Even though toddlers are no political philosophers, their claims about unfairness often work. Parents and sometimes even other siblings frequently recognise their claim as valid and undertake to remedy the situation. In other cases, parents will disagree and sometimes convince the toddler that the claim was unfounded.

But what is happening in such situations? How do we end up agreeing on a view that something is “fair” or “unfair”? This question is relevant to all the situations in which we have to allocate rights and duties. Whether this allocation is discussed openly or whether we agree on it without debate, we are guided by our sense of fairness: what is right and what is likely to be perceived as right by other people.

Even when fairness norms are not expressly mentioned, they are nonetheless in the background, shaping our views and decisions. When we cut a cake at a birthday party, we do not need to say, “I am cutting slices evenly to be fair”, but we do it anyway, and children would be quick to point out any deviation.

Situations in which rights and duties have to be allocated are pervasive. Who should have the last cookie in the jar? Who should be promoted at work? Who should be the first author on an academic paper? Who should give way in a narrow corridor? How much tax should rich people pay?

Our interests conflict, at least somewhat, whenever we have to allocate rights and duties. We want more rights and fewer duties. It is therefore striking that our social interactions involve relatively little friction in the form of open disagreement and haggling. Indeed, we are often averse to open haggling, which can feel adversarial. The absence of haggling is a kind of puzzle. How do we constantly and easily manage to solve these situations and agree on a commonly acceptable compromise?

Despite major progress in the behavioural sciences over recent decades, social scientists do not share a unified account of how people converge on specific fairness judgements across contexts, and the prevailing answers remain partial and incomplete. Thirty years ago, however, the game theorist Ken Binmore proposed a theory that is strikingly elegant and offers a compelling explanation of what fairness is and how we make fairness judgements. Unlike many theories in the social and behavioural sciences, Binmore does not build his theory from scratch. He builds on the accumulated knowledge generated by decades of work in game theory and evolutionary theory. On a topic that is quite treacherous, the rigour of game theory gives Binmore’s theory a rare clarity. I present here his theory about how we make judgements such as “it’s unfair”.

Fairness problems are everywhere

Problems about how to allocate rights and duties, resources and costs in human groups are pervasive. Their omnipresence reflects the fact that human sociality is based on cooperation. Successful cooperation requires agreement on who does what, and the benefits from cooperation naturally raise the question of who gets what.

Humans manage such allocation problems seamlessly all the time without thinking about them. So it is surprising that, when we ask “what is fair?”, the answer does not seem obvious. Equality is often mentioned, but equality is not a simple answer when people differ in their contributions, talents and needs. The term equity is sometimes preferred, but, in truth, people who use it often have only a vague idea of what the notion means in philosophy.

In the confusing maze of competing explanations and half-baked theories based on intuitions, Binmore offers a striking clarity. His naturalistic approach does not rely on metaphysical assumptions about invisible principles of morality out there. It builds from the ground up. It starts from a rigorous understanding of human interactions, of the challenges and opportunities we face, and of the stable solutions that can emerge to solve the former and seize the latter.

In my previous post, I explained how, in that framework, fairness norms are social conventions commonly agreed within a group that solve, quickly and with minimal friction, the questions of rights and duties, resources and costs.

This answer provides a radically new insight into fairness compared with the way it is discussed in society and in philosophy textbooks. It opens a path to strikingly simple and clear answers to questions that often seem like intractable metaphysical puzzles about what is right and wrong. In this post, I explain how Binmore accounts for what we come to find fair in a given social setting. To make his general theory more concrete, I begin with two familiar kinds of fairness problems.

Alice and Bob

Alice and Bob live together. They have to solve common household problems about how to share the chores needed to keep the house functional: who does the dishwashing and the laundry? Who puts the bin out? Who mows the lawn? What is a fair allocation of chores? Is it 50–50 for each chore? Across chores? What if Alice enjoys cooking more, and Bob enjoys mowing the lawn more? How should that be taken into account when deciding what is “fair”?

They also have to solve the problem of sharing the benefits of being together. For instance, they like spending the evening together watching television. But they have different preferences about what to watch. Alice prefers crime dramas, and Bob prefers sci-fi series. What is a fair way for them to share viewing time? Should it be 50–50, alternating every day or every week? What if Alice is a big fan of crime dramas while Bob only slightly prefers sci-fi series? Should they still split viewing time evenly? Would it be “fair” for Bob to ask for that?

Binmore provides a general treatment of such problems. In this post, I focus on the case in which Alice and Bob have equal bargaining power. Neither has the ability to push his or her own interest more than the other. In that case, what would they agree is a fair solution to the problems they face?

Utilitarianism and egalitarianism

Utilitarianism: maximise the sum of happiness

Utilitarianism is a moral and political philosophy that relies on a form of equality: everyone’s happiness matters equally. From that position, utilitarians argue that the right thing to do when making collective decisions is to aim for the greatest total happiness. Jeremy Bentham famously summarised this doctrine in these words:

It is the greatest happiness of the greatest number that is the measure of right and wrong. — Bentham

If Alice and Bob were utilitarians in their choice of television programme, they would choose the solution that maximises the sum of their satisfaction. Given that Alice enjoys crime dramas more than Bob enjoys science fiction series, they would end up watching crime dramas all the time.1

Egalitarianism: improve the fate of the person who is worse off

One of the landmarks of twentieth-century political philosophy was John Rawls’s A Theory of Justice, published in 1971. In it, Rawls opposes utilitarianism. He argues that it can lead to undesirable outcomes, such as the sacrifice of some individuals’ basic rights for the greater happiness of the many. In our example, Bob would have to accept never watching sci-fi series in order to maximise total happiness. Such a solution may sit uneasily with our intuitions about fairness.

In place of utilitarianism, Rawls suggests another approach. To determine what social agreement is fair, we should imagine what it would be like to be other people and to experience things as they do. He calls this thought experiment the veil of ignorance: we imagine ourselves as ignorant of our own identity, looking at a social situation while knowing that we could turn out to be any of the people involved. Rawls calls the fictitious standpoint created by this thought experiment the original position. It is from this original position that we should form a view about whether we like a social situation or not. What this thought experiment forces us to do is to consider equally the fate of everybody involved because, under the veil of ignorance, we would not know who we are in that situation.

Rawls argues that under the veil of ignorance we would choose to organise the social situation so as to focus on the benefits of the most disadvantaged person. With this conclusion, Rawls supports egalitarianism.2

Ken Binmore’s theory about how we make fairness judgements

How do we solve these problems in practice? What do we do when we assess whether a proposed solution is “fair” or not? Binmore thinks that Rawls is right to use the veil of ignorance. In fact, unlike Rawls, who sees it as something we ought to do in order to find the right solution, Binmore thinks it captures, in stylised form, something close to what we do all the time. Even though we may not think in such abstract terms, we put ourselves in other people’s shoes to see a given problem from their point of view and to look for a solution they could accept.

In fact, doing so is very intuitive to us. It amounts to following the Golden Rule.

The Golden Rule

The Golden Rule is one of the most widely shared principles of morality across human societies. Its presence across different continents and widely different faiths suggests that it was, in all likelihood, codified independently in different places. A simple version of the Golden Rule is:

Do unto others as you would like to be done unto you.

This is not just a lofty moral principle enshrined in religious texts. It is also a principle frequently used to teach children how to behave properly. Alice, learning that her toddler has hit another child, might say:

Imagine you were her. Would you be happy with what you have done? No. So you should not do that to her.

Binmore sees the Golden Rule as a cognitive device that humans evolved to help them agree on how to treat each other whenever they have to allocate rights and duties, benefits and costs of cooperation. The Golden Rule asks us to step into the shoes of others and take their point of view when deciding how to treat them. It may have emerged naturally as a way to simulate bargaining in our heads and anticipate what other people are likely to accept and what they are likely to reject.

For that reason, Binmore sees the veil of ignorance as an elaborate version of the Golden Rule that we use in everyday life to solve the many situations in which we have to agree on how to interact with other people and how to share the gains from cooperation.3

Put very simply, what we do is to place ourselves in the shoes of the people with whom we are interacting. We see the situation from their point of view. They do the same, and this process allows us to converge on shared agreements. When Alice thinks about what the fair solution is, it is as if she were placing herself in Bob’s shoes and seeing the situation from his point of view. She can then consider each option both from her own point of view and from Bob’s.4

Empathetic preferences

To put ourselves in the shoes of other people as a way of identifying what is fair, we need to be able to compare how happy we would be if we were different people in different scenarios.

In other words, Alice needs to be able to compare her and Bob’s satisfaction with different possible agreements. For Alice to appreciate that Bob may not be as happy as she would be watching crime dramas, she needs to be able to say something like “I enjoy crime dramas more than Bob enjoys them”.5

Binmore relies on the work of the game theorist John Harsanyi to give such statements formal meaning. Harsanyi formalised the idea of people having preferences not only over their own situation but also over how it compares with how others experience their situations. Binmore calls such preferences, when you put yourself in the shoes of others, empathetic preferences.

I explain Harsanyi’s theory in more detail in an appendix at the end of this post.

When Alice puts herself in Bob’s shoes while he is watching a sci-fi series, she must imagine whether Bob would be as happy in that situation as she would be watching crime dramas.6 Now, imagining the different solutions for sharing viewing time from her own point of view and Bob’s, she can choose the solution that is going to be amenable to both of them.

Binmore sees in Rawls’ veil of ignorance a way to describe this thought process where Alice gives equal consideration to her own and to Bob’s perspective. Prior to Rawls’ book, Harsanyi had already developed a moral theory based on exactly the idea of the veil of ignorance. In 1955, he described what he called a “special impartial and impersonal attitude” where someone considers

what social situation he would choose if he did not know what his personal position would be in the new situation choosen (and in any of its alternatives) but rather had an equal chance of obtaining any of the social positions'6 existing in this situation, from the highest down to the lowest. — Harsanyi (1955)

But, unlike Rawls, Harsanyi thought that under that veil of ignorance, people, not knowing who they would turn out to be, would agree on a social situation that maximised their expected well-being. In other words, Harsanyi argued that, under the veil of ignorance, we would be utilitarian. His argument would seem intuitive to any economist: if you do not know who you will be in a given situation, that situation is akin to a lottery. When you choose a lottery, you pick the one with the best expected gain.

Hence, from the same intellectual device, the veil of ignorance, Rawls and Harsanyi arrived at two different conclusions: egalitarianism and utilitarianism. Who is right?

Binmore’s Copernican move

The debates between utilitarianism and egalitarianism are complex, and the books and papers written on the topic could fill libraries. Binmore proposes a simple resolution of this debate, one that makes the issue much clearer.

Agreements in the Game of Morals need to be self-enforcing in the Game of Life

Binmore’s solution is to see utilitarianism and egalitarianism as valid answers to two different types of bargaining problems. He points out that Harsanyi and Rawls made an implicit assumption with major consequences: that the agreement under the veil of ignorance is binding. A binding agreement is like a contract signed in front of a lawyer. If one party decides not to honour the contract, a third party can intervene and enforce its terms.

If agreements about fairness are binding, then Binmore agrees that Harsanyi would have to be right and we should be utilitarian. Behind a veil of ignorance, we would choose the situation that is, on average, the best.7

The idea that agreements behind the veil of ignorance are binding is problematic, however. We should not forget that the veil of ignorance is only a thought experiment used to find a solution together in real life. There is no actual contract signed “under the veil”. How could a solution reached under the veil be binding in the real world once we step out of that thought experiment? Both Rawls and Harsanyi assume that respecting the agreement we would reach under the veil is a moral duty.8

But that is a problematic move. Where would such principles come from? Rawls’s and Harsanyi’s theories are meant to explain how we should make moral judgements. But if they assume some moral duty a priori, they assume what they are meant to explain.

Binmore rejects such a skyhook. There is, in his view, no basis for assuming that people are somehow bound to respect a hypothetical agreement reached in a thought experiment.

There is nothing about the circumstances under which people are hypothesized as bargaining in the original position that can justify the assumption that they are bound, either morally or in practice, to abide by the terms of a hypothetical deal reached in the original position. Thus, in my theory, compliance is assumed only when compliance is in the best interests of those concerned. — Binmore (1994)

Consider, for instance, a scenario in which Bob really hates dishwashing and doing the laundry, and really likes watching television. The allocation of rights and duties that maximises total happiness in Alice and Bob’s household might be for Bob to watch television after every dinner while Alice washes the dishes and does the laundry. To justify this, Bob might say: “I really dislike washing the dishes and doing the laundry more than you do, and I enjoy watching television more than you. So this is the solution that maximises our total satisfaction, and it is what we would have agreed under the veil of ignorance.” But if Alice and Bob have equal bargaining power, nothing prevents Alice from answering that she does not care about the argument that this is a “fair” solution because, under the veil of ignorance, she might have ended up being Bob and enjoying that situation. In practice, she is Alice, and she does not like the idea of such a lopsided deal.

A key point made by Binmore is therefore that an agreement in the Game of Morals only works if it is sustainable as a bargaining agreement in the Game of Life. In other words, it needs to be renegotiation-proof. It must be the case that when Alice puts herself in Bob’s shoes to consider what would count as a possible agreement, it has to be an agreement she is actually happy to respect in the real world once she steps back into her own shoes.

This has a very important practical implication. When agreements are not binding, only egalitarian deals are sustainable and renegotiation-proof.9 In an egalitarian solution, nobody has an incentive to reopen the case by saying that fairness requires a different assignment of roles, because everybody is getting the same outcome.10

Binmore, therefore, proposes an intellectually appealing way to unify our understanding of utilitarianism and egalitarianism: utilitarianism is the reasonable answer when agreements are enforceable, egalitarianism is the answer when they are not. This helps explain why both utilitarianism and egalitarianism can, to some extent, resonate with our intuitions. It is not that one is absolutely right and the other absolutely wrong. The answer depends on the context.11

When will either utilitarianism or egalitarianism prevail?

Utilitarianism will prevail when moral agreements can be binding. In real life, binding agreements typically involve a third party, such as judges and the legal system. But, from Binmore’s perspective, there is no real third party for agreements on social contracts in the Game of Life, because all the potential enforcers are themselves part of the Game of Life.

Social contracts are not contracts in the legal sense, since there is nobody outside the Game of Life to whom one can appeal for redress if someone cheats. Everybody—up to and including the Lord High Executioner—is a player in the Game of Life. — Binmore (1998)

When thinking about binding agreements, one therefore has to think about cases in which they are binding because the structure of the game itself makes violating them unattractive. Binmore gives the example of insurance games, which may have played an important role in the evolution of morality in our ancestral past.

In an environment in which daily food intake was needed for survival, but each individual faced substantial variation in success at finding food, mutual sharing makes sense as an incentive scheme. Today I get some of your meat, tomorrow you get some of mine. Respecting the insurance contract is binding because failing to respect it would trigger sanctions, such as exclusion from future help.

To the extent that these agreements can be binding, a utilitarian solution can emerge in which meat is shared. Sharing is utilitarian because the person with food shares it for the benefit of all those who are part of the insurance agreement.

Binmore conjectures that situations of insurance were likely to be at the origin of the Golden Rule.

If the Golden Rule is understood as a simplified version of the device of the original position, I think an answer to this question can be found by asking why social animals evolved in the first place. This is generally thought to have been because food-sharing has survival value. — Binmore (2005)

This logic of insurance can be extended to any situation in which people can accept losses in some cases because, across a wide range of situations in which their needs and preferences differ, they end up better off overall. Consider a couple like Alice and Bob. On any decision about how to run their household, they have to agree on their rights and duties. They can be utilitarian to the extent that there is an overall gain for both of them across all their decisions. If Alice dislike putting the bin out and mowing the lawn Bob may be happy to do those tasks most of the time. If Alice prefers choosing the interior design, Bob may be happy for her to make most of those decisions. Not all of their bargaining problems need to be solved with a 50–50 split, because they are playing a larger game in which they can divide total gains across the household. They can therefore be utilitarian in specific situations because they are egalitarian in the larger game they play at the broader household level.

Egalitarianism will prevail when agreements cannot be binding. In many cases, agreements cannot be binding. Between two people who interact only once in one specific way, there is no larger game with other situations whose potential gains can be used to discipline an agreement in that situation. In such a case, utilitarianism will not work.

If Alice and Bob are assigned to a group project and do not expect to work with each other again, Bob’s claim that he dislikes some parts of the work and would prefer Alice to do them may fall flat. Alice may simply ask for a strict equal share as a fair solution, independently of how much each of them likes or dislikes the tasks.

Similarly, even when people interact repeatedly, if they have characteristics that would systematically bias the gains from a utilitarian solution in their favour, that solution may be rejected. Let us return to the example of Bob disliking household chores more than Alice and enjoying leisure more than she does. Here, the utilitarian solution would lead to an uneven deal at the household level. Bob might try to appeal to the veil of ignorance: “Put yourself in my shoes, I really hate dishwashing.” Alice is not bound by the fiction of the veil of ignorance, and she may simply reply, “I don’t care that you really dislike it. You still have to do it sometimes.” Alice has no interest in abiding by a utilitarian solution if it puts her at a systematic disadvantage. Utilitarianism will only be followed when, overall, it works for both.

In other words, while an agreement can be utilitarian for single situations, it is only if this utilitarianism leads to a form of egalitarianism overall because the agreement over the Game of Life itself cannot be binding.

“It’s unfair”: what does it mean?

From toddlers complaining to their parents to activists demonstrating in the streets, claims about unfairness are commonplace. What do they mean? Surprisingly, those who make these claims would often struggle to articulate a coherent conceptual framework to justify them. Yet such claims work because they are real bargaining claims that we can grasp at a deeper intuitive level.

In most situations in which moral agreements are not binding, the statement “it’s unfair” has an egalitarian basis. When Alice says “it’s unfair”, she is claiming that she is the one who is worse off in the situation and that another way of organising the interaction would improve her position. There is no reason for her to agree to a situation in which she is worse off and to let the social contract on which it is based continue unchanged. Instead, she can simply say that she disagrees with that social contract and ask for another one that improves her situation. If she has equal bargaining power, her claim cannot simply be ignored.

In some situations in which agreements are binding, the statement “it’s unfair” takes on a utilitarian meaning. It becomes a claim that, in a specific situation in which it is commonly accepted that the sum of satisfaction should be maximised, the deal was not respected. This deal works as part of a larger game that is itself constrained by a broader egalitarian balance acceptable to both sides. Overall, everybody benefits from maximising satisfaction in each specific situation. But if people refuse to respect the deal when it is your turn to benefit from it, the statement “it’s unfair” calls out this breach of the commonly accepted arrangement.

Binmore’s perspective lifts the mystery surrounding questions of fairness. It helps explain why both utilitarianism and egalitarianism can feel intuitive and have defenders. And it offers a simple reason why either may prevail in a given social setting.

For most games, and in particular for the Game of Life, there is no way to make moral agreements binding. Hence, the utilitarian solution is often not sustainable there. This is simply because nothing prevents someone from saying, “I don’t care about your moral story, I am not happy with the deal you propose.” For that reason, egalitarianism typically prevails when people have equal bargaining power.

Binmore does not reach this conclusion from metaphysical or a priori moral assumptions. He builds his framework from the ground up, on the basis of a matter-of-fact understanding of human interactions, the problems they face and the solutions they can adopt. Once one takes that approach, there is an air of inevitability to the conclusions Binmore reaches. We do not reach them because we like them, and then make metaphysical assumptions along the way to help us land on these conclusions. We reach them because they follow from a naturalistic perspective that seeks to explain morality as it is, rather than describe it as we would like it to be.

References

Binmore, K. (1994) Game Theory and the Social Contract, Volume 1: Playing Fair. Cambridge, MA: MIT Press.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. Cambridge, MA: MIT Press.

Binmore, K. (2005) Natural Justice. Oxford: Oxford University Press.

Bentham, J. (1776) A Fragment on Government, Preface; in Burns, J. H. and Hart, H. L. A. (eds) (1977) A Comment on the Commentaries and A Fragment on Government. London: Athlone Press, p. 393.

Harsanyi, J.C. (1955) ‘Cardinal Welfare, Individualistic Ethics, and Interpersonal Comparisons of Utility’, Journal of Political Economy, 63(4), pp. 309–321.

Harsanyi, J.C. (1977) ‘Morality and the Theory of Rational Behavior’, Social Research, 44(4), pp. 623–656.

Rawls, J. (1971) A Theory of Justice. Cambridge, MA: Harvard University Press.

Appendix: Harsanyi’s extended preferences

In the film Crime 101, Lou (Mark Ruffalo) tells Angie (Jennifer Jason Leigh):

I like the beach much more than you do.

Such statements are easy for us to understand. But even though they are intuitive, they are not trivial. Let us ask a simple question: what does it mean to say such a thing? How can we test whether this statement is true?

For many generations of economists, such a statement would have been seen as nonsensical because we cannot compare how much Lou likes something, which is something happening in his head, to how much Angie likes it, which is also something happening in her head.

Crash course on what preferences mean

What can we say about preferences?

Let us start with a statement by Lou such as: “I like going to the beach more than I like hiking.” Economists are fine with such statements. They are meaningful because they have practical consequences. If he is repeatedly given the choice between going to the beach and going hiking, we should see Lou choosing the beach more often.

What about a slightly different statement: “I like going to the beach twice as much as I like hiking”? This now suggests a precise quantitative comparison, as if there were some quantity of subjective satisfaction in Lou’s head when he engages in an activity. He is saying: my quantity of satisfaction when I go to the beach is twice my quantity of satisfaction when I go hiking.

For most of the twentieth century, mainstream economists basically rejected such statements as unverifiable. There is no direct way to measure what is happening in Lou’s head, so such a statement appears to have no practical consequences. However, in the book that launched game theory, von Neumann and Morgenstern offered an answer to this problem. Such a statement does lead to practical predictions when we consider the willingness Lou should show to take risks for each option. If Lou says that he likes the beach twice as much as hiking, he should be indifferent between hiking for sure and a gamble that gives him a 50 per cent chance of going to the beach and a 50 per cent chance of getting nothing. More generally, if he likes the beach three times as much as hiking, the corresponding threshold would be one-third; if four times as much, one-quarter; and so on.12

Now let us appreciate that the statement “I like the beach much more than you do” introduces another level of complexity. Lou is now comparing the quantity of satisfaction in his own brain with the quantity of satisfaction in Angie’s brain. Does it make sense to do something like that? Can it lead to predictions that can be tested? Most economists would say no, because we do not have a hedonometer that we could plug into Lou’s and Angie’s heads and that would provide an absolute measure of satisfaction on a common scale.

Harsanyi proposed a way to make sense of such statements by extending choice to hypothetical choices involving a swap of places. When Lou says, “I like the beach much more than you do”, this is equivalent to saying: “I would prefer to be me, with my preferences, at the beach than to be you, with your preferences, at the beach.” Harsanyi called such preferences extended preferences. If we accept such statements as meaningful, and if we apply the von Neumann–Morgenstern result to this kind of choice, then we can represent these preferences with a utility function that allows interpersonal comparisons across people.

In other words, saying things like “I like the beach more than you do” becomes a reflection of the ability to choose between possible person-swapping experiences.

As he was launching his party’s manifesto for the 2024 British elections, the then leader of the Labour Party, soon to become Prime Minister, Keir Starmer, stated that:

[T]he pursuit of social justice and economic growth must go hand-in-hand.
— Keir Starmer (2024)

Over the past decades, the notion of “social justice” has become highly influential in public discourse. The term is now routinely invoked in political debates, policy discussions, and academic work as a guiding principle for evaluating social arrangements. Inequalities in income, wealth, education, and health are commonly assessed in terms of their fairness.

Yet, despite its ubiquity, the concept itself is rarely defined. It is largely taken for granted. What if we were to put it to the toddler’s acid test and ask a simple question: what is social justice? It is not an easy question to answer. In this post, I offer a simple answer to the question of what “social justice”, and the more traditional term behind it, “fairness”, actually mean.

What it is not

For readers unfamiliar with my previous posts, let me start by setting aside some common but misguided answers.

Fairness does not require religion to make sense

A frequent view is that fairness and justice derive from religion. Thou shalt not steal. Why? Because it is one of the commandments handed down to Moses on Mount Sinai.1

This view gets the direction of explanation wrong. Across different cultures and religions, we observe strikingly similar moral principles, such as the Golden Rule. This suggests that these principles are broadly appealing to humans and were incorporated into religious traditions that emerged independently, rather than originating from them.

Fairness does not require absolute moral laws

Another possibility is that there are objective moral laws “out there” that we can discover through reason. This position, associated with moral realism, is a secular modern version of the religious view: instead of divine commandments, there are external moral truths.

But this raises difficult questions about their nature and origin. Where do these principles come from, and how can we identify them with confidence? As I have argued in a previous post, this approach sits uneasily with a naturalistic understanding of the world. It has led many philosophers, from Kant to Parfit, into intellectual mazes with no way out, as they attempt to ground the idea that moral rules can be absolutely true.

Fairness norms are social rules

If moral and fairness norms are not externally given to us by a god, by logic or by some other thing out there, what are they? A simple answer is that they are rules of the social games we play. A very down-to-earth explanation is that moral rules are very much like those of a board game: they are not written into the fabric of the universe, but they are man-made and conventional. They are followed because they are commonly agreed upon by all participants.

For sure, moral rules feel more important than those of a board game. The reason is that they are the rules of a much more important game we play: the game of life.

[Y]es, moral rules are much more important to us than sporting rules because moral rules are the rules of the Game of Life, the one that determines our success and setbacks in life, at work, with friends or romantic partners, with family members, and so on. It makes perfect sense for us to have a moral sense that makes us care greatly about how the Game of Life is played. There is no reboot and no respawn in this game, and it determines everything that matters to us. — Optimally Irrational - Morality works without absolute moral truths

Cooperation and bargaining over its benefits

The importance of cooperation as a structuring aspect of social life

This answer raises a further question: what do we actually do in the game of life, and what kind of rules does it require? The answer is that we are a social species, and most of what we do consists of cooperating with others to achieve better outcomes. Cooperation is the scaffolding principle of life. It appears at all levels of biological and social organisation for a simple reason: when interactions are repeated, cooperating is often the best way to succeed.

Because cooperation is so pervasive, we can easily take it for granted and fail to notice it. Consider Alice, who lives in a large modern city. Every morning, she orders a coffee on her way to work. The barista makes a good coffee, and she pays for it. This may seem trivial, but many other possibilities did not occur. Alice could have run away with the coffee without paying. The barista could have used poor-quality ingredients to cut costs. What actually happens is a highly structured and mutually beneficial form of cooperation.

The same pattern continues throughout her day. She stops at a convenience store, takes a pack of biscuits, and waits in line rather than pushing ahead, even though she is in a hurry. She takes the tube and pays for a ticket, even though the gates are open. She gives way in a corridor to an elderly woman with a walker, even though she does not know her. At work, she listens to colleagues without interrupting them and contributes to a group project, even though it required giving up time she would have preferred to spend otherwise.

Nothing in Alice’s day appears remarkable. Yet it is precisely this dense web of cooperative behaviours that makes her orderly and comfortable life possible. Evolutionary anthropologist Sarah Hrdy captures this contrast with our closest relatives, the chimpanzees:

What if I were traveling with a planeload of chimpanzees? Any of us would be lucky to disembark with all ten fingers and toes still attached, with the baby still breathing and unmaimed. Bloody earlobes and other appendages would litter the aisles. — Hrdy (2009)

Cooperation allows humans to reach outcomes far beyond what any individual could achieve alone. Most of us would struggle to produce even simple goods in isolation. We cannot build a car or a phone, and most of us would not even be able to repair a television if it breaks.2 As the comedian Nate Bargatze jokes, if he were sent back in time, he would not be able to demonstrate that he came from the future: he could describe phones and satellites, but not explain how they work. What sustains our world is not individual ingenuity, but the large-scale cooperation of many people.3

Once we realise that we cooperate all the time with others to reach better situations, a natural question arises. The production of benefits by cooperation raises the question of the distribution of these benefits between the people involved.

How should the gains of cooperation be distributed?

“Who should get what?” is a question that comes naturally with cooperation. Who should get the last cookie in the jar? Who should get the promotion at work? Who should be the first author on an academic paper? Who should give way in a corridor? All these questions are about the distribution of the benefits of cooperation. Extended to society, the question of fairness points to debates about “social justice”: how much tax should the rich pay? Who should receive social subsidies—poor people, disabled people and how much?

One common mistake is to think that this question has a simple answer: equality. Everyone should get the same. But this raises an immediate issue: why equality? What principle justifies it?

Even if we accept equality as a starting point, it remains unclear what kind of equality we have in mind. Should it be equality of outcomes in all situations? If Alice did 90% of the work on a project and Bob only 10%, should they split the proceeds equally? If you meet an elderly woman in a narrow corridor, do you both have the same duty to give way? If a mother serves food to a toddler and a teenager, should both receive the same quantity?

These examples suggest that equality of outcomes is often inappropriate when people differ in their contributions or their needs. As Aristotle puts it:

The just, then, is a kind of proportion […] For if the persons are not equal, they will not have equal shares; it is when equals possess or are assigned unequal shares, or unequals equal shares, that quarrels and complaints arise.
— Aristotle

Avoiding quarrels over the distribution of the gains from cooperation requires finding appropriate proportions that will satisfy all participants. Since we do not have a simple, straight answer like “equality”, this requires a form of bargaining.

Bargaining, bargaining, bargaining

Ken Binmore, a game theorist specialised in bargaining theory, brings a key insight to this question: fairness is a solution to the pervasive problem of distributing the benefits of cooperation.

Given how often we need to agree on how to share the gains from cooperation, it would be time-consuming and frustrating if we had to haggle each time. Imagine our lives if every mundane request unfolded like this:

Alice: Can you pass me the salt please?

Bob: What am I getting in return for my effort?

This is where the rules of fairness play a role. They are meta-rules, commonly shared and understood by all. We can use them to resolve our daily problems of allocating rights and duties seamlessly. When Alice, heavily pregnant, asks Bob, a healthy middle-aged man, for his seat on the tube, she can do so because she knows that Bob shares with her a norm of fairness that prescribes that a pregnant woman should have priority for a seat. Bob knows this too and understands Alice’s request. He stands up, and the allocation of rights of access to the seat is resolved quickly and without conflict.

Fairness norms are the grammar of our social interactions. They allow us to navigate social situations with minimal friction, helping us recognise what is due to others and what we are entitled to ask for ourselves.

Fairness norms are present at all times and guide our interactions. If they are absent from our everyday discussions, it is because they do not need to be voiced or discussed as long as they are followed. It is only when there are violations or disagreements that fairness talk emerges: people queue all the time without talking, or perhaps even thinking, about queuing as a first-come, first-served fairness norm. But if someone pushes in front of them in the queue, they might interject, “You can’t do that, I was here before you!”

The game theory of fairness, explained simply

If fairness norms help us settle recurring questions about who should get what, how exactly does that work? Binmore’s answer can be expressed more precisely with the tools of game theory. The ideas are somewhat technical, but the basic structure is simple.

Fairness as a way to agree on how to share the gains from cooperation

In my previous post, I described the game theory of cooperation. I used the case of “Prisoner’s Dilemma”, an interaction between two people, let's say Alice and Bob, where they can “cooperate” (C) or “defect” (D). Depending on their mutual choices, Alice and Bob get some “payoff”, which is a general measure of whatever they care about. It can measure monetary payoffs, but it can also include other things.

If the game is played only once, defecting is the best choice in terms of payoffs. Whatever the other person is doing, choosing to defect yields a higher payoff.

But if the game is played repeatedly, cooperation becomes possible. Indeed, if there is no clear end in sight to the repetition of this game, and if Alice and Bob are patient enough and therefore care about the possibility of future gains, then cooperation can become rational: they can adopt rules of conditional cooperation whereby they cooperate if the other has been abiding by these rules. As a consequence, instead of being stuck with the (0,0) payoffs, they can reach any average payoff in the grey area below.4

For instance, they can reach an average payoff of 100 each by cooperating all the time. To do so, they can adopt the “grim trigger” strategy: cooperate as long as the other player has always cooperated; defect forever if the other player has defected at some point.5 When both Alice and Bob follow this rule, neither of them has an interest in defecting, as they would lose the benefits from future cooperation.

Other rules are possible. For instance, they could adopt the rule of alternating between (C,D) and (D,C). This is a kind of cooperation where players take turns getting the highest payoff. This rule would lead to the average payoffs (50,50), represented by point x on the graph below.

This is not, by any means, the only possibility. Another option, for instance, would be to adopt the rule of alternating between (C,C) and (C,D). If they play this game every day of the week, they could have a convention to cooperate on some days and not on others. If they play (C,C) from Monday to Saturday and (C,D) on Sunday, they would get the average payoff represented by point y on the graph below. It is close to (C,C), but one-seventh of the way towards (C,D).

What rule should Alice and Bob agree on? It is clear that some rules are obviously better than others. It is better for Alice and Bob to be at point (C,C) than at point x. Similarly, y is clearly better than x because both Alice and Bob get more. Basically, every point to the North-East of x is a better option for Alice and Bob.

Among all the possible points in the grey area, all those on the bold dark line do not have points that are better in that sense: for each point on the bold dark line, there is no other point that Alice and Bob could reach where both of them could be better off.

We call that line the efficient frontier.6 It makes sense for Alice and Bob to want to be on the efficient frontier. Being below it is “leaving some money on the table”. Both Alice and Bob would agree to move away from (D,D) to get to one of the points on the efficient frontier.

But that is the extent to which they can agree. Among all the points on the efficient frontier, Alice and Bob’s interests are at odds. Bob would prefer to be as far to the left of this curve as possible, where his payoffs are higher, while Alice would prefer to be as far to the right as possible, where her payoffs are higher.

So, in the process of deciding how to share the gains from cooperation, there is both an element of cooperation—they both want to agree on a point on the efficient frontier—and an element of conflict—they have different preferences over which point on this frontier to reach.

In short, Alice and Bob have to bargain to find a mutually beneficial solution. If they cannot agree, they might be stuck at a lower point, like (D,D). The result of this negotiation is going to be some rule they will agree to follow in order to sustain cooperation and a way to share the benefits of cooperation.

Norms of fairness, which are common knowledge in society, help coordinate Alice and Bob’s expectations so that they can quickly agree on a solution without disagreement, which could threaten cooperation and without time-consuming haggling.

Fairness is not just “equality”

At this point, you might wonder “Why all the fuss?” Isn’t it clear that the situation where Alice and Bob both play (C,C) all the time gives Alice and Bob equal outcomes and is therefore the best and fairest solution? This intuition is understandable, but it goes too fast. It is biased by the fact that, in the game above, Alice and Bob are more or less identical: we know that they have similar preferences, and we are not told anything about them differing in any important way. A bit of introspection shows that “equality” is not a trivial answer when the people concerned are different.

Let’s consider a familiar situation. Alice and Bob have to agree on what series to watch on TV tonight. In fact, they face this situation every evening. It is a classic case of bargaining: they both prefer to agree because they like to watch something together. But they also have different preferences, which means that they would prefer to agree on different things. Let’s assume, for instance, that Alice prefers crime dramas (“Crime”) and Bob sci-fi series (“SF”). Let’s now assume that Alice and Bob differ in one simple but important way: the intensity of their preferences.

Let’s also assume that Alice enjoys Crime much more than Bob enjoys SF.7 To use the conceptual tools of game theory, let’s pick some numbers to reflect their utility in each situation. We can think here of utility as their subjective satisfaction. The matrix below shows their payoffs in utility. We will assume that Alice enjoys watching Crime with Bob 10 times more than watching SF with him, while Bob enjoys watching SF with Alice only twice as much as watching Crime with her.

This game is a bit different from the Prisoner’s Dilemma. It is known as the “battle of the sexes”.8 There are two equilibria, that is, two situations where neither Alice nor Bob would want to unilaterally change their decision: (Crime, Crime) and (SF, SF). Even though Bob prefers SF, if he is currently watching a crime drama with Alice, with a payoff of 1, he does not want to leave the room to watch SF on his own, with a payoff of 0. Similarly, if Alice is watching SF with Bob, with a payoff of 1, she does not want to go and watch Crime on her own, with a payoff of 0.

While there are only two pure Nash equilibria when this game is played on one evening, repeating it every evening gives Alice and Bob much more room to manoeuvre than simply choosing SF forever or Crime forever. They can adopt a rule for how to share viewing time over time.9 Such a rule specifies what to watch each evening and is followed as long as the other person does the same. By using such contingent rules, they can generate many different average payoff combinations over time. The grey area below represents the set of average payoffs that can in principle be generated in this way.10

How should Alice and Bob decide how to agree on their viewing choices over time? This example shows that the notion of “equality” does not trivially point to a single solution. If they decide to have equal viewing time, for example by alternating each week, then they would be at point b in the picture above. Note that, when they do so, the enjoyment of Alice and Bob is different. Alice’s average satisfaction is then 5.5. It is higher than Bob’s satisfaction, 1.5. The reason is that whenever she watches a crime drama, she enjoys it much more than Bob enjoys SF. If they wish to equalise their subjective satisfaction instead, they should actually watch SF much more often together (9 times out of 10) and reach point a. They would then have equal satisfaction, but note that it would be quite low: 1.9.

What is “fair”: equal satisfaction (a) or equal viewing time (b)? Alice might argue that neither of these solutions is fair. She likes crime dramas much more than Bob likes SF. Why should they split their time evenly between them then? Indeed, given these preferences, Alice and Bob might well agree to watch SF only once in a while, while watching crime dramas most of the time. They would end up closer to point c, where the sum of their satisfaction is maximised.11

These kinds of asymmetric solutions between partners with different intensities of preference are often present because one partner is willing to give up on some of the things he or she does not care about as much as the other. One such asymmetry is comically illustrated by a scene from the film Mr. & Mrs. Smith (2005) featuring Jane (Angelina Jolie) and John (Brad Pitt) as a married couple with different preferences over the decoration of their house.

While the film plays on Jane’s fake pretence of being open to compromise, it is likely that John does not mind yielding to Jane’s wishes because he cares less about what the curtains are than she does. It is because this difference in preferences is common knowledge that Jane can claim an asymmetric bargaining solution that favours her preferences.

Norms of fairness

So how do Alice and Bob decide what is the fair sharing of viewing time between a, b, c, and all the other possible points? They could haggle to agree. But if they had to haggle every time they had to split the gains from cooperation, it would be cumbersome. They would have to debate who puts the bin out today, who does the laundry, who should repair the broken light in the pantry, and so on.

Norms of fairness are social conventions that have emerged to solve these problems in ways that are agreed upon by all. In the viewing example, Alice and Bob will share views about what kind of split each of them would expect to agree to. If it is closer to c, both Alice and Bob will understand that it is a shared expectation that the “right” way to agree is for them to watch more crime dramas. They will express this feeling by describing this solution as “fair”.

Being fair is rational

A key insight from this explanation of fairness is that it does not require us to assume that people are altruistic saints in order for them to behave fairly. Fairness rules point to equilibria of the games we play. Equilibria are self-sustaining. If you deviate from them, there are costs, typically in the breakdown of the cooperative relationship.

Being fair is rational in the sense that it pays off to follow the commonly agreed-upon rules of play about the fair allocation of rights and duties. Deviating from them is typically not worth it. For that reason, cooperation is stable. There is no need to assume a mysterious force or an external moral principle “binding” players for abstract reasons. Fairness norms are binding simply because they are equilibria and come with a structure of incentives that makes deviations unattractive.

Binmore’s argument is that fairness norms are shared conventions for solving recurring bargaining problems and reaching mutually beneficial agreements without constant haggling or mismatched expectations. This explanation demystifies fairness. Its “deflationary” nature is, however, polarising in my experience.12 Some find it extremely insightful, revealing the deep nature of fairness in a simple and almost necessarily true way. Others find it quite unappealing. The notion of fairness, intuitively, evokes something noble. Reducing it to bargaining must miss the mark, they counterargue.

To this criticism, I would stress that we should be suspicious of our intuitions as a guide to truth. Our ancestors had the intuition that the Earth was still and the universe centred around it. Their intuitions were wrong, and it is by carefully questioning them and accepting where the evidence leads us that we learned how different the world is from that view. There is no reason our intuitions should be especially accurate guides to truth. Evolution has given us intuitions to help us navigate successfully the particular environments we live in, not to understand the deep structure of the universe.

A second answer to the idea that fairness evokes something more noble than bargaining is that the fact that we like a conclusion or not cannot be an argument for or against it. Our decision to adopt a conclusion should be based only on the strength of the evidence for it, independently of whether it matches our initial preferences. Binmore’s framework provides the most compelling explanation of what fairness is and how it works. He grounds his explanation in fundamental and universal aspects of human life: the pervasiveness of cooperation and the associated need to agree on how to share the gains from this cooperation.

This post offers an introduction to Binmore’s theory of fairness. My next post will address some natural questions that arise from this introduction to Binmore’s theory of fairness: How do fairness norms work in practice to help us solve our everyday problems? How do they evolve over time? Does this emphasis on bargaining mean that might makes right?

References

Binmore, K. (1994) Game Theory and the Social Contract. Volume 1: Playing Fair. Cambridge, MA: MIT Press.

Binmore, K. (1998) Game Theory and the Social Contract. Volume 2: Just Playing. Cambridge, MA: MIT Press.

Binmore, K. (2005) Natural Justice. Oxford: Oxford University Press.

Friedman, M. (1980) Free to Choose. New York: Harcourt Brace Jovanovich.

Harsanyi, J.C. (1977) Rational Behavior and Bargaining Equilibrium in Games and Social Situations. Cambridge: Cambridge University Press.

Hartley, L.P. (1953) The Go-Between. London: Hamish Hamilton.

Hrdy, S.B. (2009) Mothers and Others: The Evolutionary Origins of Mutual Understanding. Cambridge, MA: Harvard University Press.

Kant, I. (1998) Groundwork of the Metaphysics of Morals. Translated by M. Gregor. Cambridge: Cambridge University Press.

Labour Party (2024) ‘Keir Starmer launches “Change” – Labour’s general election manifesto’, 13 June. Available at Labour Party website.

Luce, R.D. and Raiffa, H. (1957) Games and Decisions: Introduction and Critical Survey. New York: Wiley.

Nayyeri, M.H. (2013) Gender Inequality and Discrimination: The Case of Iranian Women. New Haven, CT: Iran Human Rights Documentation Center.

Pareto, V. (1971) Manual of Political Economy. Translated by A.S. Schwier and A.N. Page. New York: Augustus M. Kelley.

Parfit, D. (2011) On What Matters. Oxford: Oxford University Press.

Rawls, J. (1971) A Theory of Justice. Cambridge, MA: Harvard University Press.

Read, L.E. (1958) ‘I, Pencil’, The Freeman, December. Available via Liberty Fund and FEE.

Starmer, K. (2024) ‘Speech at Labour Party manifesto launch, Manchester, 13 June 2024’. Labour Party.

2

Another illustration of the extraordinary feats of human cooperation was famously given by Milton Friedman, who used the example of a simple pencil to explain why no single individual could have made it.

Look at this lead pencil. There is not a single person in the world who could make this pencil. Remarkable statement? Not at all.

The wood from which it’s made, for all I know, comes from a tree that was cut down in the state of Washington. To cut down that tree, it took a saw. To make the saw, it took steel. To make the steel, it took iron ore.

This black centre, we call it lead but it’s really graphite, compressed graphite. I’m not sure where it comes from, but I think it comes from some mines in South America.

This red top up here, the eraser, a bit of rubber, probably comes from Malaya, where the rubber tree isn’t even native. It was imported from South America by some businessmen with the help of the British government.

This brass ferrule—I haven’t the slightest idea where it came from—or the yellow paint, or the paint that made the black lines, or the glue that holds it together.

Literally thousands of people cooperated to make this pencil: people who don’t speak the same language, who practise different religions, who might hate one another if they ever met. — Source

10

For readers with advanced knowledge in game theory, strictly speaking, the Folk Theorem applies only to the subset of this region that gives each player at least his or her minimax payoff, which can be interpreted here as the long-run disagreement point if Alice and Bob cannot agree. If we confine attention to pure strategies in the stage game, the minimax payoff for each player is 1. For Bob, if Alice chooses Crime, his best response is Crime, which gives him 1; if Alice chooses SF, his best response is SF, which gives him 2. The minimum of these two maxima is therefore 1. The same reasoning gives a minimax payoff of 1 for Alice. The Folk-Theorem payoff region is therefore the subset shown below. Note that if mixed strategies are allowed, the minimax payoffs are lower: 10/11 for Alice and 2/3 for Bob.

Trivers was one of the most—perhaps the most—influential evolutionary biologists of the 20th century. His work should be much more widely known in social and behavioural sciences, in particular in economics, as Trivers’ intellectual approach is very much in line with a game theoretic understanding of social interactions.

It is hard to overstate the importance of his work. Einstein famously published four groundbreaking papers in 1905, a year often referred to as his “Annus mirabilis”, during which he revolutionised physics. Trivers might be said to have had a “Quinquennium Mirabile” for the five years between 1971 and 1976, during which he produced a series of ideas that revolutionised evolutionary biology.

Reciprocal altruism - 1971

Evolution is often conceived as implying that people should be selfish and cynical. This view is mistaken. As early as Darwin, evolutionary thinkers have suggested that cooperation was fully compatible with evolution. That being said, how cooperation evolved was, for a long time, an unresolved problem. One seemingly intuitive answer was proposed by Vero Wynne-Edwards: altruism is good for the group and hence altruism will be selected to help the group survive. Some old animal documentaries illustrated this idea, describing the old wildebeest allowing itself to be caught and eaten by the lion so that the younger ones in the herd could survive.

This idea, now labelled “group selection”, does not work. Selection operates at the individual level. If altruists sacrifice themselves for the group, the group might benefit, but the altruists in it will tend to disappear over time. So, self-sacrificial altruism is not something that we would expect to be selected.1

In 1966, the evolutionary biologist George Williams proposed an alternative solution in his book, Adaptation and Natural Selection. He argued that a lot of apparently “group-beneficial” helping can, in principle, be compatible with natural selection when helping tends to be repaid inside stable social relationships.

Robert Trivers built on this insight and published, in 1971, one of the most influential papers in evolutionary biology, The Evolution of Reciprocal Altruism. In it, he describes how conditional rules of the form “I scratch your back if you scratch mine” could naturally evolve and explain the prevalence of cooperation in the animal world.

The human altruistic system is a sensitive, unstable one. Often it will pay to cheat: namely, when the partner will not find out, when he will not discontinue his altruism even if he does find out, or when he is unlikely to survive long enough to reciprocate adequately. And the perception of subtle cheating may be very difficult. Given this unstable character of the system, where a degree of cheating is adaptive, natural selection will rapidly favor a complex psychological system in each individual regulating both his own altruistic and cheating tendencies and his responses to these tendencies in others. As selection favors subtler forms of cheating, it will favor more acute abilities to detect cheating. — Trivers (1971)

Trivers then goes on to explain the rich tapestry of human moral emotions: we long for good friends who are likely to be good, we get angry at cheaters and can be willing to punish them at substantial costs to ourselves, we feel gratitude and sympathy towards altruistic acts and guilt towards our own violations of the implicit rules of reciprocity.

This emotional tapestry creates the setting for even more complex games, where people leverage these emotions strategically. Trivers, for instance, describes how some cheaters can use these emotions to their advantage.

Apparent acts of generosity and friendship may induce genuine friendship and altruism in return. Sham moralistic aggression when no real cheating has occurred may nevertheless induce reparative altruism. Sham guilt may convince a wronged friend that one has reformed one’s ways even when the cheating is about to be resumed. Likewise, selection will favor the hypocrisy of pretending one is in dire circumstances in order to induce sympathy-motivated altruistic behavior. — Trivers (1976)

Trivers’ insights align closely with those of game theory on the rationality of cooperation in repeated interactions. Indeed, Trivers was aware of the game-theoretic results and mentions them in his article.

Reciprocal altruism has become one of the main explanations of the emergence of cooperation between non-kin. Cooperation does not require society to be populated by saint-like figures; it works with humans as they are, warts and all. It is indeed the blend of cooperation and conflict in social interactions that explains the rich nature of our social emotions and the many mini intrigues layered into our social relations.

Parental investment -1972

One year after his paper on reciprocal altruism, Trivers published another major paper, Parental Investment and Sexual Selection. This provides a simple and illuminating answer to a question asked from time immemorial: why are men and women different?

Trivers starts from a very simple basic fact: men and women differ in the investment they put into making a child. In sexual reproduction, a male and a female each produce gametes, and a new child is developed from the fusion of the two. All known animals that reproduce sexually are anisogamous: they have different gamete sizes.2 We conventionally call females the sex with the largest gamete size and males the sex with the smallest.

This difference in gamete sizes creates an asymmetry that puts members of both sexes on different strategic paths to achieve higher fitness. With a lower investment in any given child, males have a greater incentive to look for many females to provide their gametes to. On the contrary, females have to be more cautious. Any child is a more costly investment for them. Because they invest more, they have fewer opportunities to have children. It is therefore worth investing more in each of them.

Since the female already invests more than the male, breeding failure for lack of an additional investment selects more strongly against her than against the male. In that sense, her initial very great investment commits her to additional investment more than the male’s initial slight investment commies him.3 — Trivers (1972)

In the class of mammals, this asymmetry builds up from a fairly small difference between sperm and egg into massive differences in biological investment. In humans, women carry and sustain a developing baby for nine months. One would therefore expect that these very different investment costs and benefits lead to very different behavioural strategies and psychologies for anything related to sexual behaviour.

Indeed, since men are seeking a mate who will bear most of the initial investment required to bring a child into the world, they evolved a psychology that is relatively more promiscuous and oriented towards short-term mating. A philanderer can potentially initiate several baby-making processes at little physiological cost to himself. On the other hand, women should care more about what men are bringing to the table; they should therefore be relatively more concerned with the quality of the genes provided and, if possible, with the willingness of the man to commit to a long-term relationship and invest his time and resources in raising their children.

Trivers uses differential parental investment to explain a number of patterns observed across the animal kingdom: the greater tendency of males to desert their partners, the greater choosiness of females, who typically decide with whom to mate from a pool of pretenders, and the greater, sometimes violent, competition between males. More broadly, this framework also helps explain associated sex differences, such as higher male mortality and greater male body strength in species where success depends on winning intra-male competitions.

Critics of evolutionary theory sometimes argue that it does not make any predictions that can be tested and that it only rationalises what has already been observed. Trivers’ work is one of the best examples disproving this accusation. In his paper on parental investment, Trivers argues that the differences in behaviour between males and females should reflect the degree of asymmetry in their parental investment. As a result, animals with more parental investment asymmetry should show greater asymmetry than those with less, and if we ever find animals with role reversals, we should also observe reversals in strategies. And indeed, we observe that in animals with less asymmetry in parental investment, like swans, the differences between males and females are less noticeable. In the rare cases where male investments are larger, like in seahorses, where the females literally place their eggs in the belly of the male who incubates them, we observe a role reversal, with females courting males and competing for access to them.

Parental investment theory offers a simple and compelling answer to the age-old question of why men and women differ in their preferences and psychological traits—often captured in the popular expression that men are from Mars and women are from Venus: much of this can be traced back to the asymmetric size of gametes, which generates broader asymmetries in investment. Men’s and women’s fundamental differences in these preferences and traits are not a reflection of social indoctrination;4 they are adaptive strategies that differ because men and women have been dealt different cards by nature in the game of life.5

Parent Offspring Conflict - 1974

In 1974, Trivers published a paper that speaks to any parent: Parent-Offspring Conflict. In this article, he explains that while parents and children are genetically closely aligned—which explains the close cooperation between family members—they are not perfectly aligned. There are always elements of conflict, and recognising this helps make sense of the sometimes complex dynamics within families.

Following the now widely accepted gene-centred view of evolution, evolution selects traits that maximise the chance of our genes being reproduced. From that perspective, children's and parents’ genetic interests are not identical. Children should care about their own success and, to a lesser degree, about the success of their siblings with whom they share, on average, 50% of their genes.

Parents, on the other hand, are equally related to their children. They should care about these equally. In addition, they should care about themselves above and beyond caring about their kids, to the extent that they could have additional children in the future.6 This leads to several areas of tension.

Children have an interest in overclaiming the attention and resources of their parents. Parents of newborns are familiar with the unrelenting demands of their baby, waking up during the night, crying frequently, and often draining parents of energy. Parents end up conflicted because, while they love their child, they would often want to give less attention than what is requested from them. They would like to sleep more, have more time for themselves, and so on. But from the baby’s point of view, it is optimal to ask for more resources than parents are willing to give. Any resource received by the baby 100% benefits him or her. Any resources (including health) saved by the parents might be used to have children later, but this is not as important for the baby as the immediate benefits of additional resources received now.

Hence, there are constant conflicts, with children asking for more resources than their parents are willing to give them. Weaning a child, which is usually required for a woman to ovulate again and have additional children, is, for instance, often a challenge, as the child resists it.

Obviously, children cannot argue like lawyers, so they compete for greater attention and resources using what Trivers calls “psychological manipulation”.

The offspring can cry not only when it is famished but also when it merely wants more food than the parent is selected to give. Likewise, it can begin to withhold its smile until it has gotten its way. Selection will then of course favor parental ability to discriminate the two uses of the signals, but still subtler mimicry and deception by the offspring are always possible. — Trivers (1974)

In fact, the conflict happens already before birth, in the mother’s womb. Foetuses overclaim maternal resources, slightly to the detriment of the mother’s health. Mothers’ physiology has been designed to counterbalance these claims, and the balance reached is the result of an internal tug-of-war. Some significant health issues associated with motherhood are a reflection of an imbalance in this internal battle. The tendency to experience diabetes during pregnancy can, for instance, be seen as one reflection of this conflict, with the foetus and placenta pushing for greater access to maternal glucose than is optimal for the mother’s own health.

Obviously, overall parents tend to love their children and children tend to love their parents, but Trivers showed—with a theory now largely supported by empirical research— that the whole picture is more complex, because there are always also elements of conflict in parent-offspring relations.

Self-deception - 1976

There is a widely known tendency for people to engage in motivated reasoning and believe that they are better than they are. Psychologists have often explained this as a reflection of the fact that we enjoy having flattering beliefs. An evolutionary perspective makes this answer somewhat puzzling. Evolution does not select psychological traits that make us happy, but traits that make us successful. Hence, if we tend to delude ourselves into thinking that we are better than we are, there must be a reason outside of our mind: it must somehow be useful.7

In the preface to Dawkins’ The Selfish Gene, Robert Trivers proposed a solution to this problem: our tendency to self-deceive, to think we are better than we are, may serve as a mechanism that enables us to deceive others more effectively. He wrote:

If … deceit is fundamental to animal communication, then there must be strong selection to spot deception and this ought, in turn, to select for a degree of self-deception, rendering some facts and motives unconscious so as not to betray – by the subtle signs of self-knowledge – the deception being practiced. —Trivers (1976)

Commenting on this assertion, psychologist Steven Pinker remarked, “This sentence... might have the highest ratio of profundity to words in the history of the social sciences” (2011).

Trivers starts from the idea that, in communication, deception is widespread. This is a reasonable assumption. As stated by Dawkins (1976): “It may well be that all animal communication contains an element of deception right from the start, because all animal interactions involve at least some conflict of interest.”

In a 2011 paper with Bill von Hippel, Trivers developed this idea further, listing how self-deception can help. When trying to deceive, people may face cognitive load (the cognitive work required to make sure a web of lies does not have glaring contradictions). Given that lying is a betrayal of trust and is sanctioned when it is found out, it is risky, and people can get nervous about being found out, possibly showing signs of nervousness. Finally, people might try to mask signs of nervousness, thereby also behaving in a way that indirectly suggests lying. Self-deception, by inducing people to believe in their own lies, so to speak, can eliminate these possible clues while leading others to believe the preferred story of the person self-deceiving.

Trivers’ theory of self-deception has been supported by empirical research (including research I have contributed to). It explains what seems to be one of the most irrational patterns of human behaviour as emerging from strategic incentives.

Trivers has been one of the most influential evolutionary biologists, and his papers are still worth reading today. His insights, published more than 50 years ago, are fascinating. They often align very well with economic theories of behaviour, and it is therefore regrettable that his ideas are not more well-known in economics, and in particular in behavioural economics.

A key feature of Trivers’ take across these contributions was to see that beneath the world of social interactions we observe, there are deep structures in terms of incentives that shape the game we play. Understanding these games and their structures helps us make sense of the seemingly endless complexity of human psychology and social dynamics. In several key contributions, Trivers helped lift the veil on the underlying logic of human behaviour.

References

Coleman, R.M. and Gross, M.R. (1991) ‘Parental investment theory: the role of past investment’, Trends in Ecology & Evolution, 6(12), pp. 404–406.

Darwin, C. (1859) On the Origin of Species. London: John Murray.

Dawkins, R. (1976) The Selfish Gene. Oxford: Oxford University Press.

Dawkins, R. and Carlisle, T.R. (1976) ‘Parental investment, mate desertion and a fallacy’, Nature, 262, pp. 131–133.

Pinker, S. (2011) The Better Angels of Our Nature: Why Violence Has Declined. New York: Viking.

Sargent, R.C. and Gross, M.R. (1985) ‘Parental investment decision rules and the Concorde fallacy’, Behavioral Ecology and Sociobiology, 17, pp. 43–45.

Trivers, R.L. (1971) ‘The evolution of reciprocal altruism’, The Quarterly Review of Biology, 46(1), pp. 35–57.

Trivers, R.L. (1972) ‘Parental investment and sexual selection’, in Campbell, B. (ed.) Sexual Selection and the Descent of Man 1871–1971. Chicago: Aldine, pp. 136–179.

Trivers, R.L. (1974) ‘Parent-offspring conflict’, American Zoologist, 14(1), pp. 249–264.

Trivers, R.L. (1976) ‘Foreword’, in Dawkins, R. The Selfish Gene. Oxford: Oxford University Press.

Trivers, R. and von Hippel, W. (2011) ‘The evolution and psychology of self-deception’, Behavioral and Brain Sciences, 34(1), pp. 1–16.

Williams, G.C. (1966) Adaptation and Natural Selection: A Critique of Some Current Evolutionary Thought. Princeton: Princeton University Press.

Wynne-Edwards, V.C. (1962) Animal Dispersion in Relation to Social Behaviour. Edinburgh: Oliver & Boyd.

There are few thinkers whose writing remains relevant over time. Darwin is one of them. As our understanding of human behaviour progresses, it is surprising to see how much he got right about it. Most people associate Darwin with the view of evolution as being a fight of all against all. However, in his second book dedicated to humans, The Descent of Man, he presents a very insightful understanding of human psychology, which gives its full place to cooperative behaviour. Of particular interest is the fact that he describes the good reasons why cooperation may exist and why people tend to be willing to cooperate with others:

[A]s the reasoning powers and foresight of the members became improved, each man would soon learn from experience that if he aided his fellow-men, he would commonly receive aid in return. From this low motive he might acquire the habit of aiding his fellows; and the habit of performing benevolent actions certainly strengthens the feeling of sympathy, which gives the first impulse to benevolent actions. Habits, moreover, followed during many generations probably tend to be inherited. — Darwin

Darwin provided two answers. The first one was to stress the self-regarding consequences of altruistic actions: helping others would increase the likelihood of aid to oneself in times of need. The second one was to stress the importance to the individual of the praise and blame of neighbours in stimulating virtuous behaviour. Strikingly, these two explanations—unified in the Folk Theorem—form the backbone of game theorists’ and evolutionary biologists’ modern understanding of the roots of cooperation.

The Folk Theorem

The Prisoner’s Dilemma is one of the most famous games from game theory. In it, two prisoners are presented with opportunities to “rat” out the other to get a better deal from the police. They can choose to stay silent (cooperate with each other) or to talk (defect). The paradox of the Prisoner’s Dilemma is that both players have an individual interest in defecting. But if they follow their individual interest and both defect, then they end up in a situation where they are worse off than if they had both stayed silent. This is somewhat frustrating, and that is the reason it is a “social dilemma”. The more general lesson is that there are situations such that when everybody follows their individual interest, everybody ends up worse off than if they had cooperated.

Some quick thinking lets us realise that these kinds of situations are actually not that infrequent. Consider, in everyday life, a collective project whose outcome depends on people in a group working hard on it. Everybody wants the project to be successful, but for a given participant, it might be more convenient not to work too hard and piggyback on the work of others. Such incentives can lead group work to fail with not enough people pulling their weight for the project to be successful.

The result of players’ rational behaviour in a Prisoner’s Dilemma is a Nash equilibrium. It is a situation where, when all players anticipate a pattern of play from all players, none of them has an interest in changing strategy. In the group example, if group participants expect that others won’t work, they have no reason to work themselves. So the failure to get the group working is stable in the sense that everyone’s actions are compatible with their expectations about what others will do. But note that the fully cooperative situation where everybody works in the group might not be stable because if everybody works, some might consider that they might as well shirk and benefit from the fruits of the collective work nonetheless.

The Prisoner’s Dilemma was first studied in this form by Merrill Flood and Melvin Dresher, two analysts at the RAND Corporation.1 In early 1950, they invited two rigorous thinkers, Armen Alchian (an economist at UCLA) and John D. Williams (a RAND mathematician), to play 100 rounds of the game. Interestingly, the two did not simply play the one-shot Nash prediction (mutual defection) round after round. Instead, they experimented for a while, with Williams trying to induce Alchian to cooperate, and overall mutual defection was relatively rare.

Flood and Dresher asked John Nash what to make of this. He answered that the observed behaviour and the attempt at cooperating should not be seen as abnormal. The “100 rounds” should be treated as one big game, not as 100 separate one-shot games. In that setting, a strategy can include rules about how to react to what the other player has done. Conditional strategies of the form “do this if the other did that” can be an equilibrium of this larger game.2

Very early in the history of game theory, it became understood that repeated interactions create the opportunity to sustain cooperation. In their 1957 classic book on game theory, Luce and Raiffa described in this way the possibility of cooperation in the repeated Prisoner’s Dilemma (emphases mine):

[W]e see that in the repeated game the repeated selection of (cooperate, cooperate) is in a sort of quasi-equilibrium: it is not to the advantage of either player to initiate the chaos that results from not conforming, even though the non-conforming strategy is profitable in the short run (one trial).

It is intuitively clear that this quasi-equilibrium pair is extremely unstable; any loss of “faith” in one’s opponent sets up the chain which leads to loss for both players. — Luce and Raiffa (1957)3

This understanding was so widespread that the formal result, first published by Aumann (1959), was later called the Folk Theorem.

The folk theorem explained intuitively

The intuition of the folk theorem is very easy to understand. Imagine two gangsters who plan an exchange of money and drugs. They would have no qualms about robbing each other. If they have to organise a one-off transaction, they face a Prisoner’s Dilemma. Both would be happy if the transaction happens as planned, but each would be even better off if they could get the other gangster’s property without having to give theirs. Gangster movies are replete with scenes where such exchanges end up in betrayal, and one party ends up dead.

However, the strategic nature of this interaction changes radically if they have the opportunity to interact regularly over time (e.g. in a drug deal where one brings money and the other the substance). They can engage in regulated cooperation, respect rules, and benefit from these interactions.

The reason is that the prospect of possible future cooperation has a policing effect on the present. The “shadow of the future” is cast over present interactions.4 For fear of losing the gains from future cooperation, both gangsters may end up cooperating in each period.

The folk theorem with minimal maths

Consider the Prisoner’s Dilemma matrix of payoffs below. For each pair of actions, the cell contains the payoffs of Player 1 and Player 2 (in that order). The Nash equilibrium is the situation where both defect. It leads to a situation that is not “socially optimal”.

The insight from the Folk Theorem is simple: when play is indefinitely repeated (repeated without a clear end in sight), then players can do better than the Nash equilibrium of the stand-alone game. They can adopt strategies of conditional cooperation of the form: I will cooperate now if the other has cooperated before. The simplest form of such a strategy is the “grim strategy”: I will cooperate if the other person has always cooperated before. If the other has ever defected, I will defect.

Now the key is that there should be no clear end of cooperation in sight. There should be a high enough probability each period that the game will be played again, and both players should care enough about the payoffs in the future (they should not be impatient).5

When this is the case, the Folk Theorem indicates that, via strategies like the grim strategy, a lot more average payoffs can be obtained than the payoffs of the defect-defect scenario of one-shot games. Indeed, it is possible for the players to reach all the average payoffs in the grey area in the graph if they are patient enough and the probability of the game repeating is large enough.

The conclusion is that high levels of cooperative payoffs can be reached in repeated interactions, even in situations where no cooperation is actually stable in single interactions, if players care enough about the future. Players can adopt conditionally cooperative strategies, and it is the conditionality of these strategies that enforces the behaviour of the players in the present.

In short, the folk theorem says that once interactions are repeated, players can adopt a shared understanding of the type “I’ll be nice as long as you are nice”. This is sustainable and individually rational (no need to assume that people are altruistic saints).

An equilibrium here takes the form of a commonly agreed rule of behaviour. This rule determines how to act in each period. A given rule leads to an average payoff in the long run. Consider, for instance, the grim strategy rule: people cooperate as long as everybody has always cooperated. This rule delivers the payoff associated with full cooperation (C,C) over the long run because nobody ever deviates.6

Defining formally cooperation

Given the framework above, we are actually in a position to formally define what cooperation is. We do not need to say that cooperation is something like being “nice” (which would require defining what “nice” is) or that it is what is socially “right” (which would require defining what “right” is). We only need to observe that when players play (C,C), they are achieving a higher payoff by deviating from the individually rational strategy of the one-shot interaction. Hence, formally, cooperation can be understood as following an equilibrium strategy in a repeated game that yields higher social payoffs than the equilibrium payoffs of the one-shot game.7 In plain English, cooperation is not adopting a short-sighted, self-centred behaviour and instead trying to work with others to do better in the long run.

Self-sustainable via built-in sanctions

Sustained cooperation is made possible by the risk of potential sanctions in the future. And this potential risk of sanctions is credible because the one that would not implement them would also be punished. One might fear that this cannot work because this logic would lead to an “infinite regress”: If Alice does not do the right thing, Bob needs to punish her, and if Bob does not punish Alice, Candice needs to punish Bob, but if Candice does not punish Bob, you need somebody, like Dan, to punish Candice, and so on. If the population is finite, there is somebody who would have to punish others without fearing to be punished himself or herself if he or she failed to do so. But as stated by Ken Binmore:

[T]he proof of the folk theorem is explicit in closing the chains of responsibility. — Binmore (1998)

Bob might punish Alice because he fears Candice might punish him, and Candice might punish Bob because she fears that Alice might punish her! The punishment is often simply the withdrawal of cooperation, the severing of ties that lead to the social isolation of the punished.

If this description seems far-fetched, consider the social dynamics of “cancellation”. People who were the target of cancellation often explain that many of their friends and colleagues reach out privately to express support but did not dare to speak publicly for fear of also being sanctioned by their association with the person being cancelled.8 People fear not only the possible negative judgements from others about what they say, but also potentially the judgment from others about whether they are displaying the correct type of judgement themselves. In a cancellation event, everybody might express publicly what they think is the publicly appropriate attitude because they fear that everybody else might punish them if they do not conform.

Game theory and evolutionary biology

The logic of the folk theorem provides a unifying explanation of the emergence of cooperation as arising from the fact that, whenever people interact indefinitely over time, they can get better by deviating from their one-period best strategy. This deviation is sustainable as a rational strategy when players adopt conditionally cooperative strategies and would sanction deviations.

This explanation of cooperation is very familiar to economists. It is, somewhat surprisingly, less familiar to evolutionary biologists and psychologists who are often unaware that the folk theorem provides a general result that underpins much of what they discuss under labels such as reciprocity, indirect reciprocity, and reputation.

Kin selection. One important observation in animal behaviour is that cooperative behaviour often emerges between kin (e.g. parents-offspring, sisters, closely related kin groups). Here, the explanation from a game theoretic point of view is simple. Evolution selects strategies that maximise fitness at the gene level. Behaviour in one individual that promotes the survival and reproduction of the same genes in another individual will tend to be selected.

Kin share a lot of genes. Siblings share 50% of their genes, uncles and nephews, 25%, cousins 12.5%, and so on. This naturally pushes towards the selection of caring for the success of one’s kin. As the saying goes, “blood is thicker than water”.9

A simple way to think about it is that instead of caring about only your own payoff, you care also about the payoff of your kin to the degree to which you are related. As famously said by evolutionary biologist John Haldane:

Let’s take the Prisoner’s Dilemma above and let’s consider two situations: first the case where the gangsters are brothers, second, the case where the gangsters are twins. Let’s assume that the players are driven by their genes to maximise their genetic fitness. If they are simply brothers, they should care fully for their own material payoffs and care for 50% of the material payoff of their brother. If they are twins, they should both just care about the sum of their material payoffs. We can right away see that this “caring for the other payoffs” leads to the disappearance of the dilemma. Cooperation quickly becomes the best strategy in terms of evolutionary payoffs. The more related the players are, the more likely a Prisoner’s Dilemma situation turns into a trivial cooperative situation.10

Reciprocal altruism. In 1966, the evolutionary biologist George Williams published a book, Adaptation and Natural Selection, where he argued that a lot of apparently “group-beneficial” helping can, in principle, be compatible with natural selection when helping tends to be repaid inside stable social relationships.

The evolutionary biologist Robert Trivers built on this insight and published, in 1971, one of the most influential papers in evolutionary biology, The Evolution of Reciprocal Altruism. In it, he describes how conditional rules of the form “I scratch your back if you scratch mine” could naturally evolve and explain the prevalence of cooperation in the animal world.

For biologists, Trivers’ theory is the leading explanation of cooperation. Trivers’ insights are quite fascinating, and he discusses a rich texture of social behaviour which goes well beyond the result from the folk theorem in the simplified setting of the Prisoner’s Dilemma. He also grounded his arguments in compelling behavioural data about cooperation in the animal world across many different species.

However, it would be wrong to think that Williams’ and Trivers’ contributions were independent of the insights gained from game theory. Williams was aware of the discussion in game theory and specifically saw an organism’s behaviour as the best response to an environment shaped by other organisms’ behaviour. Even more tellingly, as indicated by Trivers himself, he was well aware of the literature in game theory where repeated interactions in a Prisoner’s Dilemma were being discussed and studied. He even quotes Luce and Raiffa’s book, where they had suggested that cooperation could emerge as a “fragile quasi-equilibrium”.

The relationship between two individuals repeatedly exposed to symmetrical reciprocal situations is exactly analogous to what game theorists call the Prisoner’s Dilemma (Luce and Raiffa, 1957). — Trivers (1971)

One can therefore see game theorists’ and Trivers’ contributions as complementary. The Folk Theorem provides the formal proof that cooperation is an individually rational strategy, which could therefore be sustainable in the long run, provided players can adopt appropriate rules of cooperation. Trivers made a compelling case about how such behaviour can emerge from evolution, how it is actually widely present in the animal world, and the type of mechanisms that ensure its sustainability.

Indirect reciprocity. In 1987, the evolutionary biologist Richard Alexander published the influential book The Biology of Moral Systems, where he argued that the one-to-one type of reciprocity from reciprocal altruism and repeated Prisoner's Dilemmas could not explain cooperation in large-scale society. Instead, he proposed the term indirect reciprocity to characterise the fact that we don’t only cooperate with people who have cooperated with us in the past but with people who also have cooperated with others.

Independently of this development in evolutionary biology, game theorists extended Folk Theorem results to interactions in large populations where people are rematched with others each period. In such a setting, cooperation can be maintained by keeping a public record of each person’s past cooperative behaviour and by making everybody’s behaviour conditional on these public records. An equivalent of the grim strategy in that context is that if one person ever defects, nobody ever cooperates with him again.11 Here again, strategies of conditional cooperation, like the grim strategy, can lead to cooperation being an equilibrium. Everyone cooperates with those who have cooperated in the past and everyone cares about their public record to be able to benefit from future gains from cooperation. These results provide a formal proof that the type of cooperation described by Alexander can be an equilibrium and therefore socially stable. 9

These extensions of the Folk Theorem to cooperation in large populations stress the importance of reputation: it is our public record as a good member of the community. It determines our future opportunities to benefit from cooperation in interactions with other people. Everybody cooperates with everybody having a good reputation because it is the best thing to do. Honesty is the best policy because a loss of reputation comes with substantial costs in the form of a loss of opportunities to cooperate with others in the future. For that reason, we care a lot about our reputation. It is built slowly and lost quickly.

Partner choice. In real life, we indeed choose, to a large extent, who our friends, collaborators, exchange partners, and so on are. Roberts (1998) and Baumard, André and Sperber (2013) developed an evolutionary account of cooperation that captures this fact. They made the case that understanding the logic of cooperation requires more than understanding what happens within a relationship; it requires understanding how relationships form in the first place. A lot of what people do is identify good partners and try to be selected as partners by others. Building a good reputation is key in that view, not just to convince our current partners to cooperate with us, but to find good partners in the first place.

The Folk Theorem has also been extended to such a setting.12 In that case, cooperation can be sustained by severing ties with defectors and refusing to match with them, and in some environments, leaving them unmatched. In short, we can shun people who have not proved to be cooperators. This helps explain why so much human activity involves gossip, that is, exchanging information about other people's good and bad deeds. While gossip has a bad name, its prevalence reflects the importance of forming good judgements about others to help us make good decisions when considering them as potential partners.

Implications

The Folk Theorem as a fundamental explanation of how and why cooperation emerges in evolution

The insight of the folk theorem is quite deep: opportunities for mutually beneficial cooperation naturally emerge when players face the prospect of interacting repeatedly over an indefinite period of time.

In a sense, the gains from cooperation are up for the taking. Purely self-centred agents who stumble on rules of conditional cooperation, or who are smart enough to devise such rules, will greatly benefit from working together.

The folk theorem captures the general strategic logic underlying most non-kin explanations of cooperation. The main genuinely distinct alternative is kin selection, where cooperation can be favoured even without the strategic enforcement logic of repeated interaction because genetic relatedness partly aligns evolutionary interests.13

There are endless ways to cooperate, hence culture matters

The folk theorem has two major implications. The first one is that cooperation is possible and can be individually rational. The second one is that cooperation can take many, many forms. As shown with the graph of the average payoffs reachable with the logic of the folk theorem, there is an infinite number of possibilities. More importantly, there are typically many ways to secure a given equilibrium payoff. That is, for every point in the shaded area, there are several rules of behaviour which will deliver that average payoff.

This result has been received with quite a bit of despair by game theorists. Having a unique equilibrium in a game allows game theorists to make a “prediction” about how rational players would play that game. Having an infinite number of equilibria means that the model does not narrow down a specific prediction. It is seen as a weakness of a game-theoretic model.

The answer in the profession has been to largely look away from repeated games. Instead, influenced in part by the rise of behavioural economics and the inclusion of psychology in economics, economists have looked at the behaviour of players in one-shot games. As players typically do not behave as purely self-interested and motivated by material interest, looking at one-shot games has provided the opportunity for a large literature to emerge on social preferences.

But this methodological move, understandable given the logic of the sociology of science, is most certainly misguided. Whatever social preferences we have, they must, in all likelihood, have been selected for us to successfully navigate situations of repeated interactions. In repeated interactions, our social preferences are useful for finding cooperators, being fair, and avoiding being seen as a defector. These social preferences likely drive people’s behaviour in one-shot experiments because one-shot interactions are unusual and people naturally use their built-in cognitive tools to try to make sense of these situations and decide how to act. By focusing on studying “social preferences” in one-shot games, economists have focused on simulacra: the effects of preferences forged to play in repeated games when activated in unusual situations where interactions are one-shot (and typically anonymous).

While this literature has produced a tremendous quantity of papers, it has likely been a wrong turn in terms of strategy for making sense of cooperative preferences driven by the desire of economists to say “something” in games with one or only a few equilibria.

A classic joke in economics recounts the tale of an economist looking for his keys under a lamppost. When someone asks where he lost them, he answers that he lost them quite a bit further away, but that it is only under the lamppost that there is light to look at the ground. Similarly, the fact that one-shot games often have one or very few equilibria made these games a preferred setting for the investigation of cooperative preferences even though the real explanations of these preferences lie in a very different area, the area of repeated games.

The fact that there are countless possible ways to cooperate should have led economists down another path, the path of understanding how cooperative equilibria are selected within a given society. This path requires thinking of how different cultural norms of cooperation evolve in societies. It is a path taken by a few economists whose influence in the discipline should be much more important: Robert Sugden, Christina Bicchieri and Ken Binmore.14

The game theory of cooperation explains the key characteristics of human cooperation: what it is and how it works. It provides a key insight: cooperation arises even between people who might have conflicting incentives because people can often produce higher total payoffs by working together. If they interact over time, they can design rules for conditional cooperation that allow them to produce these higher payoffs and to share them.

Seen in that light, there is nothing mysterious about cooperation. There is no need to assume that people are altruistic in a way that would conflict with the laws of evolution. Our moral sense, with its strong emphasis on reciprocity and conditional cooperation, is designed to navigate precisely these types of situations where gains can be obtained from cooperation if it is mutually enforced by agents playing nice as long as others do.

References

Alexander, R.D. (1987) The Biology of Moral Systems. New York: Aldine de Gruyter.

Aumann, R.J. (1959) ‘Acceptable Points in General Cooperative n-Person Games’, in Luce, R.D. and Tucker, A.W. (eds.) Contributions to the Theory of Games IV (Annals of Mathematics Studies, 40). Princeton, NJ: Princeton University Press, pp. 287–324.

Axelrod, R. (1984) The Evolution of Cooperation. New York: Basic Books.

Baumard, N., André, J-B. and Sperber, D. (2013) A mutualistic approach to morality: The evolution of fairness by partner choice. Behavioral and Brain Sciences, 36(1), pp. 59–78

Bicchieri, C. (2006) The Grammar of Society: The Nature and Dynamics of Social Norms. Cambridge: Cambridge University Press.

Binmore, K.G. (1994) Game Theory and the Social Contract. Vol. 1, Playing Fair. Cambridge, MA: MIT Press.

Binmore, K.G. (1998) Game Theory and the Social Contract. Vol. 2, Just Playing. Cambridge, MA: MIT Press.

Darwin, C. (1871) The Descent of Man, and Selection in Relation to Sex. London: John Murray.

Dawkins, R. (1976) The Selfish Gene. Oxford: Oxford University Press.

Ellison, G. (1994) ‘Cooperation in the Prisoner’s Dilemma with Anonymous Random Matching’, The Review of Economic Studies, 61(3), pp. 567–588.

Flood, M.M. (1952) Some Experimental Games. Research Memorandum RM-789-1. Santa Monica, CA: The RAND Corporation.

Gintis, H. (2006) ‘Behavioral Ethics Meets Natural Justice’, Politics, Philosophy & Economics, 5(1), pp. 5–32.

Kandori, M. (1992) ‘Social Norms and Community Enforcement’, The Review of Economic Studies, 59(1), pp. 63–80.

Laclau, M. (2012) ‘A Folk Theorem for Repeated Games Played on a Network’, Games and Economic Behavior, 76(2), pp. 711–737.

Luce, R.D. and Raiffa, H. (1957) Games and Decisions: Introduction and Critical Survey. New York: John Wiley & Sons.

Roberts, G. (1998) Competitive altruism: From reciprocity to the handicap principle. Proceedings of the Royal Society B: Biological Sciences, 265(1394), pp. 427–431.

Schumacher, H. (2015) ‘On Repeated Games with Endogenous Matching Decision’, Journal of Institutional and Theoretical Economics (JITE), 171(3), pp. 544–564.

Sugden, R. (1986) The Economics of Rights, Cooperation and Welfare. Oxford: Basil Blackwell.

Trivers, R.L. (1971) ‘The Evolution of Reciprocal Altruism’, The Quarterly Review of Biology, 46(1), pp. 35–57.

Williams, G.C. (1966) Adaptation and Natural Selection: A Critique of Some Current Evolutionary Thought. Princeton, NJ: Princeton University Press.

The whole Darwinists teaching of the struggle for existence is simply a transference from society to living nature of Hobbes’s doctrine of bellum omnium contra omnes [war of all against all].1 — Engels (1875)

The image of a war of all against all is a recurring framing of evolution. Thomas Henry Huxley, who became known as “Darwin’s Bulldog” for his staunch defence of Darwin’s theory, accepts this description and invites us to act against it by being ethical:

As I have already urged, the practice of that which is ethically best–what we call goodness or virtue–involves a course of conduct which, in all respects, is opposed to that which leads to success in the cosmic struggle for existence. In place of ruthless self-assertion it demands self-restraint; in place of thrusting aside, or treading down, all competitors, it requires that the individual shall not merely respect, but shall help his fellows; its influence is directed, not so much to the survival of the fittest, as to the fitting of as many as possible to survive. It repudiates the gladiatorial theory of existence. — Huxley (1893)

This view has often made it into social and political discussions, where evolutionary theory, and in particular its application to the study of human behaviour, is taken to imply a bleak vision of humans as being irremediably selfish. In his text The Western Illusion of Human Nature, the anthropologist Marshall Sahlins argues that evolutionary psychology has reinforced a Western trope of antisocial human nature:

The complementary idea that self-love is only natural has been reinforced lately by a wave of genetic determinism featuring the "selfish gene" of the sociobiologists and the revived Social Darwinism of the evolutionary psychologists. — Sahlins (2008)

This view is paradoxical. Anybody thinking that the core message of evolutionary theory is that we live in a war of all against all should stop and look around. Everything about life, as we can observe it, is produced by cooperation. Cooperation is not in conflict with evolution, it is generated by it.2

Cooperation is everywhere in nature

The evolutionary psychologist Nichola Raihani wrote a book, The Social Instinct, on the importance of cooperation in the natural world. In an interview about it, she stated:

The history of life on Earth is a history of teamwork, collective action, and cooperation. Cooperation pays because being part of a team is better than going it alone. — Raihani (2021)

The parliament of genes

Richard Dawkins’ The Selfish Gene made the point that genes are the units upon which evolution works. They are the replicators, which replicate and mutate. But in their drive for replication, genes “discovered” that they are stronger together. Instead of remaining isolated replicating molecules, they gathered in large “vehicles”, the cells and organisms, in which they share a fate and increase their chance of replication.

We are survival machines—robot vehicles blindly programmed to preserve the selfish molecules known as genes. — Dawkins (1976)

How cooperation is sustained. Within a cell or a multicellular organism, genes share a common “interest”. Their replication depends on the organism surviving, developing properly, and reproducing. Because genes that only “care” about their own replication tend to be selected, there is always the risk of mutations that increase their own transmission, potentially at the expense of the organism.

A standard example is meiotic drive (segregation distortion): during meiosis, a gene can sometimes bias transmission so it is inherited by more than 50% of offspring, even if this slightly reduces fertility or harms the organism. In short, genes can face prisoner’s dilemma-type tensions: cooperation is best for all, but cheating can be best for one, which makes cooperation fragile.

As a consequence, the cellular architectures that have emerged from evolution include mechanisms that detect and eliminate cheating. Distorters are countered by suppressors. This kind of internal governance has been described as a “parliament of genes” by evolutionary biologist Egbert Leigh in his 1971 book Adaptation and Diversity: Natural History and the Mathematics of Evolution.

The symbiosis at the heart of our cells

We tend to think of our cells as singular entities. The reality is that in each of our cells there are two different genomes collaborating. In addition to the one present in our cells’ nucleus, there is also the DNA present in mitochondria, the organelles in charge of producing the energy (ATP molecules) for the cell. These organelles, present in all eukaryotic cells (those of all animals, plants, fungi, and many single-celled organisms), are widely understood to be the remnants of an ancient bacterium absorbed by a cell and maintained in a symbiotic relationship.

The proteins that mitochondria need are largely encoded in the nucleus. The nucleus sends the instructions, the cell builds the proteins in the cytoplasm, and those proteins are imported back into the mitochondria. Meanwhile, mitochondria provide the energy that makes the whole operation possible. This division of labour within eukaryotic cells is one of the bases of complex multicellular life on Earth.

How cooperation is sustained. Because mitochondria have their own genome and replicate within cells, there is always a risk of cheating: some variants can favour their own proliferation even if that undermines cellular performance. The nucleus needs mitochondria to produce energy rather than prioritise their own replication. This is what economists call a principal–agent problem, where a principal relies on an agent to perform a task even though the agent’s incentives may not be fully aligned with the principal’s. Evolution has solved this problem by putting mitochondria under nuclear control and surveillance. Mitochondria depend on nuclear-encoded machinery, dysfunctional ones are preferentially cut off and removed by cellular quality control.

Stronger together: the emergence of multicellular organisms

After joining forces within cells, cells also “found out” that working together can be good for replication, and therefore for the genes they host.

Multicellularity likely started with simple clumps of cells staying together, sometimes in structures resembling microbial biofilms, where cells are glued together by a matrix of secreted molecules. One main benefit is a reduced risk of predation. Modern laboratory evolution experiments show that multicellular clumps are more likely to form when a predator is introduced into the environment.3 The mechanism is simple: clusters are harder to eat. Becoming larger, even crudely so, can be enough to survive.

But once cells remain together across generations, new possibilities open up. Some cells can specialise. Others can protect, transport, or support. What begins as a simple size advantage becomes a platform for internal division of labour and more complex organisation, eventually supporting the evolution of large multicellular organisms.

How cooperation is sustained. Multicellular organisms are complex things, but cooperation within them is relatively easy to maintain because cells share the same genes. They are clones, so their genetic interests are aligned. That is why nearly all cells in your body are set up to live and die selflessly, only so that your gametes can produce new organisms.

Interspecies cooperation

Once cells are united into multicellular organisms, another level of cooperation becomes possible: between organisms. Interestingly, such cooperation emerged even between organisms that are not closely related and belong to different species.

A classic example is the relationship between plants and fungi. Most plants rely on mycorrhizal fungi that attach to their roots. The fungi extend the plant’s reach into the soil, improving access to water and nutrients such as phosphorus. In return, the plant supplies sugars produced by photosynthesis.

Another well-known example is cooperative interactions between different fish species, such as cleaner fish and their clients. Cleaner fish remove parasites from larger fish, gaining food while providing a service. Clients choose which cleaners to visit and abandon those that cheat. Cleaners, in turn, adjust their behaviour to maintain a good reputation.

Many ecosystems depend on cross-species partnerships. In particular, more than 80% of land plants form mycorrhizal associations, which makes this one of the most widespread symbioses on Earth.

How cooperation is sustained. Because the partners are not genetically aligned, interspecies cooperation is always exposed to cheating: one side can take the benefit while reducing what it provides in return. What keeps this in check is strategic enforcement. Partners can stop cooperating, switch to alternative partners, or reduce the flow of benefits to poor performers. Plants, for instance, can shift carbon towards fungal partners that deliver more nutrients and away from those that deliver less, while fungi can preferentially supply hosts that provide more carbon. In cleaner-fish systems, clients simply leave and choose other cleaners, which makes cheating costly and rewards cleaners that maintain a good reputation.

Social animals

The benefits of cooperation are often easier to see within a species, especially when organisms live in small communities with close kin relationships. Social insects like ants and bees are a well-known case. Their genetic system can make sisters unusually closely related: in haplodiploid species, sisters can share around three quarters of their genes. That tends to align interests and can reduce some genetic conflicts, which makes cooperation easier to stabilise.

Cooperation also appears in many vertebrates, particularly those living in groups with repeated interaction and some degree of kin structure. Meerkats are a good example: individuals take turns acting as sentinels, watching for predators while others forage. Apes provide another set of examples, with grooming, alliance formation, and coordinated conflict. Among apes, humans pushed this further, relying on cooperation at a scale that far exceeds what our individual bodies would allow.

How cooperation is sustained. As with interspecies cooperation, cooperation within groups of social animals relies on strategic enforcement: cheaters can be detected and punished, excluded, or avoided in future interactions. Cooperation is also easier to sustain because many groups are kin groups, so members have partly aligned genetic interests. In social insects like ants and bees, haplodiploidy means full sisters can share around 75% of their genes, which makes their incentive to cooperate unusually strong and helps sustain extreme levels of cooperation.

Humans: the social brain advantage

Describing the ecological success of our early ancestor Homo habilis, E.O. Wilson said:

These slender little people, the size of modern twelve-year-olds, were devoid of fangs and claws and almost certainly slower on foot than the four-legged animals around them. They could have succeeded in their new way of life only by relying on tools and sophisticated cooperative behavior. — Wilson (1978)

The distinctive feature of human cooperation is that it can take place in large groups of strangers who are not closely genetically related, and therefore do not have closely aligned genetic interests.

This kind of cooperation is hard to achieve in new situations. It requires substantial cognitive work to understand the goals of others, to find mutually acceptable solutions, and to ensure that agreements are respected by all parties. The social nature of our environment is likely what created strong evolutionary pressure for improved cognitive abilities. Our ancestors faced an evolutionary arms race for cognitive capacities that help them take advantage of social cooperation and avoid being left behind or taken advantage of.

Those who were able to make friends, negotiate coalitions, and gain the trust of others were more likely to survive and leave offspring than those who did not. This is why the main driver of the outstanding ability of humans to reason was likely not to understand the world, but to understand and convince others.

How cooperation is sustained. Using their brains, humans have been able to sustain cooperation at a scale unmatched in the animal world, not just through one-on-one monitoring but through shared social rules that are followed and enforced collectively. This is a key insight from economist Elinor Ostrom. In potentially conflictual situations, humans show an ability to design and implement rules of cooperation, monitor compliance, and sanction defectors.4

Cooperation: what it is and what it means

Cooperation emerges at every level of interactions

It is striking that cooperation emerged naturally at every step of life: genes cooperate in cells, cells cooperate in organisms, organisms cooperate in groups. The repeated emergence of cooperation at each level of organisation is one of the most striking phenomena generated by evolution. Cooperation is a scaffolding principle of life. Without it, nothing like the living organisms we observe would exist.5

What insights can we take from this reality when thinking about what it means for human societies?

The illusion of a Hobbesian state of nature

The idea that a population of self-driven agents trying to get the best outcomes for themselves would be locked into a perpetual war of all against all misses that one of the best ways to thrive, even in a competitive environment, is cooperation. This is illustrated in one of the scenes of The Hunger Games, which purports to represent exactly a battle royale, a fight of all against all. As Peeta enters the training centre with Katniss, he reminds her of the importance of forming alliances:

Remember, Katniss, today’s about making allies. - Peeta Mellark in The Hunger Games: Catching Fire (2013)

The fact that one can be stronger together has not been lost by evolution. It has found architectural solutions to make cooperation between replicating units work and be resilient to attempts by some units to break cooperation to their advantage.

The Hobbesian state of nature is a misleading idea. It never existed, neither between humans, nor between other living organisms.6

The illusion of unconditional cooperation

While the pessimistic cynicism of the Hobbesian state of nature is misguided, another possible error is to take an overly idealistic view of cooperation, hoping for people to always be kind and cooperative with each other.

While cooperation is everywhere in life, it emerged not from unconditional altruism among cooperating units, but from the mutual advantage they gain from cooperating. As Raihani said in an interview:

Cooperation evolves because it allows entities to get ahead. And in the end, on a genetic level, there have to be somehow benefits that either derive back to the individual, or via its relatives, for cooperative strategies to be under positive selection. — Raihani7

Because units cooperate to get ahead, their divergent interest is always a possible threat to cooperation.8 Therefore, whenever cooperation is stable, it is kept in place by mechanisms that prevent deviations and organise the split of the gains from cooperation between units that each would benefit from getting a larger share of the collective benefits.

The implications of these insights for political ideologies’ take on cooperation

Because navigating social cooperation is required for humans to succeed in life, our evolved moral sense values cooperation. And, likely because being seen as a strong cooperator is advantageous in society, we like to think (possibly to convince others) that we are strong cooperators. Hence, the view that we should all just be nice with each other, and that cooperation should be pursued as an absolute “Good”, may have an intuitive appeal. This could help explain the recurrent appearance of collectivist ideologies in history, from the Essenes in ancient Judaea, to the Taborites in early 15th-century Bohemia, to the Diggers in mid-17th-century England, and later to communism in 19th-century Europe.9

Religions and political ideologies that simply call for humans to be good are not offering sustainable social solutions because cooperation requires mechanisms and institutions in place to keep individual conflicts of interest in check. Without these, attempts at unconditional cooperation are bound to fail, as illustrated by unsuccessful attempts at socialism, from kibbutzim to large national states.10

However, the total opposite view, which would deny the importance of cooperation and the tremendous gains reached through collective action, is also misguided. In a famous speech, the British and conservative Prime Minister Margaret Thatcher once said:

There is no such thing as society. There are individual men and women, and there are families. — Thatcher (1987)

This view is like saying that there are no cells, just genes. But, in the same way as genes were able to do much more by joining efforts into cells, humans have been able to do much more by cooperating together in large social groups. Indeed, it is only their ability to cooperate that made humans take over the world.

Evolution is too often described as implying only a competition between individuals. Contrary to this view, it is important to see how evolution has driven the emergence of cooperation at all levels of life because individual units can often be much more successful working together.

Appreciating the centrality of cooperation as a scaffolding principle of life is not naively idealising it or calling for it to happen out of sheer altruism in society. The lesson for us is twofold: cooperation can be highly beneficial, but it needs carefully crafted solutions to keep in check the individualist tendencies of cooperating agents. Evolution took eons to stumble on such solutions. Humans are in a unique position to use their agency and their cognitive capacity to engineer cooperation. The key challenge is to find institutional solutions to leverage the gains from cooperation and limit conflicts. What these institutions can be will be the topics of future posts in this series.

References

Boraas, M.E., Seale, D.B. & Boxhorn, J.E. (1998) ‘Phagotrophy by a flagellate selects for colonial prey: A possible origin of multicellularity’, Evolutionary Ecology, 12, pp. 153–164. doi:10.1023/A:1006527528063.

Dawkins, R. (1976) The Selfish Gene. Oxford: Oxford University Press.

Engels, F. (1859) Letter to Karl Marx, 11 December 1859, in Marx, K. and Engels, F. Marx and Engels Collected Works, vol. 40: Letters 1856–1859. London: Lawrence & Wishart.

Engels, F. (1875) Letter to Pyotr Lavrov, 12–17 November 1875, in Marx, K. and Engels, F. Marx and Engels Collected Works, vol. 45: Letters 1874–1879. London: Lawrence & Wishart.

Huxley, T.H. (1893) ‘Evolution and ethics’ (Romanes Lecture, 1893), in Huxley, T.H. (1894) Evolution and Ethics and Other Essays. London: Macmillan.

Kropotkin, P. (1902/1939) Mutual aid: a factor of evolution. London: William Heinemann.

Leigh, E.G. (1971) Adaptation and Diversity: Natural History and the Mathematics of Evolution. San Francisco: Freeman, Cooper.

Marx, K. (1861) Letter to Ferdinand Lassalle, 16 January 1861, in Marx, K. and Engels, F. Marx and Engels Collected Works, vol. 41: Letters 1860–1864. London: Lawrence & Wishart.

Ostrom, E. (1990) Governing the Commons: The Evolution of Institutions for Collective Action. Cambridge: Cambridge University Press.

Raihani, N. (2021) The Social Instinct: How Cooperation Shaped the World. London: Jonathan Cape.

Raihani, N.J. and Power, E.A. 2021, ‘No good deed goes unpunished: the social costs of prosocial behaviour’, Evolutionary Human Sciences, vol. 3, e40.

Sahlins, M. (2008) The Western Illusion of Human Nature: With Reflections on the Long History of Hierarchy, Equality and the Sublimation of Anarchy in the West, and Comparative Notes on Other Conceptions of the Human Condition. Chicago, IL: Prickly Paradigm Press.

Thatcher, M. 1987, Interview for Woman’s Own, 23 September.

Wilson, E.O. (1978) On Human Nature. Cambridge, MA: Harvard University Press.

5

The evolution of cooperation: its different types and time of emergence (colour coded from green to orange):

Where does morality come from? Why should we be moral? These questions are, surprisingly, mysterious given that moral beliefs and practices are pervasive in our lives.

For centuries, a straightforward answer in countries with monotheistic religions was: “it comes from God’s will”. Sacred books gave (often very detailed) injunctions about what to believe and what to do in order to be a “good” person.

The European Enlightenment witnessed a secularisation of thought in science and philosophy. In that context, the Scottish philosopher David Hume proposed a radically different view (which I develop on this Substack): morality is only a human affair. Moral rules are social conventions that make human interaction and cooperation possible.1 There is no need to invoke anything “out there” to explain why we care about morality and why we (most often) follow moral rules.

The view of morality as arising from social conventions can feel underwhelming. One might think that something reassuringly “absolute” is lost. Isn’t there a “Right” and a “Good” that we are meant to follow because they are true independently of what we think?2

Contra Hume, the German philosopher Immanuel Kant defended an absolute view of morality within a secular theory. Kant is often described as the central figure of modern philosophy. In his History of Western Philosophy (1945), Bertrand Russell described Kant as:

[Being] generally considered the greatest of modern philosophers — Russell (1945)3

and The Stanford Encyclopedia of Philosophy starts its article on Kant with the following description:

Immanuel Kant is the central figure in modern philosophy.

Kant’s philosophy concerns both what we can know about the world (Critique of Pure Reason) and what we should do with this knowledge (Critique of Practical Reason). In this second aspect of his work, Kant argued that the moral “ought” is unconditional and universal. Morality is not a matter of convention. It stems from human rationality.4

Kant’s project can be thought of as retaining the unconditional character of Christian moral prescriptions, without appealing to divine command. Once we abandon religion as a foundation of morality, Kant’s enterprise is one of the most influential attempts to recover an absolute view of morality. In his view, moral rules are necessary if we want to live as rational beings. Even if everybody disagreed with these rules, they would nonetheless be true.5

In spite of his fame, we can now say, with the benefit of two more centuries of work on rational decision-making, that Kant got it wrong. In his books on game theory and the social contract, Binmore offers a frank criticism of Kant, which I will broadly develop here.

[Kant] gets pretty much everything upside down and back to front. — Binmore (2005)

The categorical imperative

Kant aims to found morality on rationality. He explains his views in the Groundwork of the Metaphysics of Morals. The key idea he defends is that moral behaviour consists in following moral “oughts” that do not depend on incentives, enforcement, or local convention. These oughts stem from a single principle, the categorical imperative:6

Act only on that maxim through which you can at the same time will that it should become a universal law.7

There have been many criticisms of the impracticality of Kant’s moral principle. One of them, raised during Kant’s lifetime by the French political thinker Benjamin Constant, is that if one follows Kant’s categorical imperative, one ought to tell the truth to a murderer who knocks at our door and asks whether his intended victim is in our house. Kant replied without denying this implication. He stated that lying in such a situation would “do wrong to men in general”.8 So when a Nazi officer asks you whether you are sheltering Jewish children, the moral thing to do, on this strict reading, is to tell the truth. If you lie, what next? Trust in each other’s words would crumble in society!

Here, I present a criticism that is more fundamental than these familiar objections. My claim is that Kant’s assertion that the categorical imperative follows directly from human rationality is misguided.

The contractual intuitions behind Kant’s morality

Before taking down Kant’s argument, it is worth appreciating its intellectual appeal. There is a contractualist intuition behind Kant’s morality. This intuition is not the one Kant uses as an explicit argument, but I think it is what made his view compelling.

Because we live in society, we need rules to organise social interactions. What rules defining duties and rights can we endorse? If these rules have to be accepted by all, and if we have similar bargaining power, a simple logic emerges: we cannot defend rules that give rights to ourselves and impose duties on others in a way that does not apply symmetrically. Hence, in a society of equal members, the only rules of behaviour that we can claim to be allowed to follow are those that we must accept could be followed by others.9

This contractualist intuition makes Kant’s argument appealing, but it is important to distinguish two different questions:

1. The social question (a social contract):

   How should we all agree on shared social rules—a “social contract”—in a given community?

   The contractarian position I defend in this series is that morality exists to sustain such a social contract. That is why we intuitively feel that we cannot claim a right to do things to others that we would not accept them doing to us.

2. The individual question (a rule for personal conduct):

   How should you behave as an individual?

   This is an individual choice you make for yourself, not a collective choice you make with others.

The intuitive appeal of Kant’s answer comes, I think, from implicitly channelling our contractual intuitions about the social question into the individual question. But Kant is not searching for social rules to adopt as a group. He is looking for a principle of behaviour that each person should adopt independently. Kant’s answer is misguided because the contractarian answer to the social question is not an answer to the individual question.

The flaw in the argument

In Natural Justice, Binmore makes this point, which is ironic but goes to the crux of the flaw in Kant’s argument:

Kant claimed that a truly rational individual will necessarily observe one particular categorical imperative: “Act only on the maxim that you would at the same time will to be a universal law.” My mother had similar views. When I was naughty, she would say, “Suppose everybody behaved like that?” Even to a child, the flaws in this line of reasoning are obvious. It is true that things would be unpleasant if everybody were naughty, but I’m not everybody—I’m just myself. — Binmore (2005)

The key point is that Kant tells us it is rational to follow a rule that would work well if everybody else were following it. But our adoption of that rule is a decision we make on our own, with no effect on other people’s decisions. What if others do not follow suit? Is it still rational?

Starting with a well-known example: the Prisoner’s Dilemma

At this point, we benefit from the clarity that game theory brings to thinking about rational decisions in social interactions. The Prisoner’s Dilemma is a particularly useful case for testing Kant’s conclusion. The dilemma involves two people who can either cooperate with each other or not.10

I will use a version of the dilemma that is, deliberately, stripped of moral sentiment between the players.11 Consider two gangsters who plan to exchange diamonds for cash. They can only meet briefly in a train station. Because the place is public and the meeting must be quick, they can only swap briefcases and leave, without checking what is inside. Each gangster faces a choice: he can honour the deal (cooperate) and bring the promised item, or he can bring an empty briefcase (defect) in the hope of getting the other briefcase for free.

Assume the two gangsters do not know each other and will travel to different countries immediately after the exchange, never to meet again. Their decision has no future consequences for them. What should they do?

Because they have no personal connection, they do not care about each other’s wellbeing. In that case, it quickly becomes clear that the individually rational choice for each is to defect. Consider the buyer. Two states of the world are possible: either the seller brings the diamonds, or he does not. In either case, the buyer is better off giving nothing, whether he receives diamonds or nothing. The seller faces the same logic: he is better off bringing nothing.

The dilemma is that if both follow their individual rationality, the exchange fails, even though both would prefer the outcome where the cash and the diamonds are successfully traded. A tremendous amount has been written on this problem. Because the conclusion is uncomfortable, many authors have tried to argue that it would somehow be “rational” to cooperate. We need to put this idea to rest: it is an intellectual dead end. If we assume that the players do not care for each other and will not interact in the future, the only rational strategy (the best strategy for them to get what they care about) is to defect.12

Kant’s categorical imperative conflicts with this conclusion. It suggests that cooperation is the rational choice because it is the kind of action one could accept as a rule for everyone. If both cooperated, the exchange would take place; if both defected, it would not.

But the structure of the Prisoner’s Dilemma shows why this is not a usable principle for individual action. The problem is that choosing a maxim because it would be good if it were universal does not make it universal.13 In the gangster exchange, the only thing each person can choose is his own action. There is no point saying “this would be a great action if everybody chose it” if the other person has no reason to choose it.

Choosing to follow the categorical imperative would lead to a better world only if my choice could somehow influence others’ choices. But that is not the case. In the example above, one gangster’s decision to cooperate does not produce some “spooky action at a distance” that makes the other gangster cooperate as well.14

Criticising the core of Kant’s argument about the categorical imperative

Let us now turn to Kant’s argument that the categorical imperative stems from the requirements of human rationality.

[T]he will of every rational being is necessarily bound to it as a constraint. — Kant

Binmore takes this argument seriously. What should a maxim of behaviour chosen by a rational being be? The notion of rationality is not simple,15 but we can start from a minimal idea: behaviour is rational if it can be rationalised, in the sense that one can give reasons for it.16

A formal insight from economics is that rationality can be characterised, to some extent, by consistency. If a person’s choices satisfy certain basic consistency requirements, those choices can be described as if the person had a stable objective.17

Binmore begins from this point and asks whether Kant’s categorical imperative follows naturally from the search for consistent principles of behaviour. A first (small) problem is that Kant’s test is applied maxim by maxim. That leaves room for overly specific maxims. For instance, regarding the challenge of whether you should tell the truth to a Nazi looking for Jewish people hiding in your house, one could adopt the maxim:

Never tell a Nazi who is looking for innocent victims where to find them.

That is, of course, a defensible maxim. But it illustrates the problem: once we allow very narrow conditions, it becomes easy to tailor a maxim to reach the conclusion we want. If the conditions are specific enough, the “universality” of its content can become almost empty, because it may in practice apply only to one person.18 The question then becomes: why these conditions, and why this maxim rather than another? In practice, it looks as though we need further principles to justify the way we chose to describe the maxim in the first place, for example a principle about protecting innocent people.

For this reason, Binmore does not consider maxims individually, but as a whole. If we consider the full set of principles that would be implied by the categorical imperative, we end up with a system of rules (maxims) guiding action.

So consider an individual choosing a set of rules to follow. A simple requirement of consistency is that the set of rules should not undermine itself: following those rules should be compatible with continuing to follow them. Put differently, a coherent system of rules should be self-justifying. If you apply your own rules to the question “which rules should I adopt?”, they should not force you to abandon themselves. Binmore expresses this idea as a rational imperative to choose for yourself a bundle of maxims (my phrasing for simplicity).

Choose rules for yourself that you can stick with when you reflect on your own rule-choosing.

If one associates rationality with avoiding inconsistency in the principles guiding behaviour, this requirement is not controversial. It may sound abstract, so an example helps. Suppose your overarching rule is:

In every situation, choose the option that best advances your aims, given what you believe about the situation.

That rule is compatible with continuing to follow it. By contrast, consider an overarching rule such as:

Always do the opposite of what this system recommends.

That system cannot be self-justifying. If you try to follow it, it tells you not to follow it.

Now we can ask a similar question at the social level: what rules could everyone adopt together, and still have reason to keep following? An answer would be:

Choose rules for society that people can keep sticking with once everyone has adopted them.

In other words, if we had to choose as a society, we should prefer rules that are self-sustaining, in the sense that if everyone adopts them, each person still has reason to keep following them rather than immediately wanting to switch.19

This addresses the social question: what rules can serve as a stable social contract? But Kant is not trying to answer that question. He is trying to answer the individual question: what rules should each person adopt for themselves?

Kant’s prescription is that you, as an individual, should choose rules for yourself that you would accept everyone using. Binmore rephrases Kant’s categorical imperative as:

Act on the basis of a system of maxims that you would at the same time will to be universal law. (I emphasised the addition of “a system of”)

We can rephrase this, for simplicity, as:

Choose rules for yourself that you could at the same time will everyone to use.

The problem is what “will” means here. You may want others to follow your principles, but your choice of principles has no causal effect on what they choose. You can decide that a rule would be appropriate for everyone, but that decision does not make anyone else follow it. You cannot “will” other people into compliance just by endorsing a rule.

In the Prisoner’s Dilemma, the buyer might decide to cooperate because the exchange succeeds if everybody cooperates. But the buyer’s choice of maxim has no effect on the seller’s choice of maxim.20 As Binmore puts it:

[I]t is impossible for an individual to make what Kant calls a “natural law” that everybody should behave as though they were clones. Indeed, it seems to me quite bizarre that a call to behave as though something impossible were possible should be represented as an instruction to behave rationally. Far from expressing a “rational preference”, the “will” of Kant’s categorical imperative seems to me to represent nothing more than a straightforward piece of wishful thinking.

Binmore’s complaint is that Kant’s test tempts us to choose the “best” action by imagining an ideal world in which everyone complies. To caricature, one might summarise the categorical imperative as:

• Choose to behave in a way that would be great if everybody else were doing it.

But if you are looking for a rational answer to the individual question, you should instead look for the best action for the individual, given what others are actually doing. If others are like you, they will also try to choose what is best for them given what everyone else is doing. In other words, looking for a consistent rule of behaviour from the individual point of view leads to a different kind of categorical imperative, one in which people aim to make decisions consistent with their preferences, assuming others are also doing the same. Binmore proposes something like (my phrasing):

• Choose to behave in a way that is best for you, given everyone else’s choices, assuming that others are also choosing what is best for them, given everyone else’s choices.21

An individually rational rule of choice that could be adopted by all is one in which everyone chooses what is best for them (given their preferences), assuming that all other people are also trying to do the same.

So this maxim tells you that it is rational to behave in a way that assumes realistic behaviour from other people (and not idealised behaviour), with each person also having realistic assumptions about the behaviour of others. A situation where everybody mutually best responds to other people’s behaviour is a Nash equilibrium. For that reason, Binmore calls this second imperative the “Nash categorical imperative”.

Binmore is not presenting this as a moral principle. He is presenting it as a requirement of rational choice in strategic settings. It does not ask you to assume that others will behave more cooperatively than their incentives allow. A “rational” rule of choice, in this sense, is one that can be used by everyone at once, with each person still having reason to stick with it given that everyone else is doing the same.

Rationality is playing the best response against actual behaviour

The categorical imperative recommends behaving in the best possible way IF everybody were willing to behave that way.22 But in reality, people may have good reasons not to. If so, what happens if you follow the categorical imperative and end up being the only one who does? In many settings, doing the “right” thing in that sense can lead to worse outcomes when others do not follow you. Here are two illustrations.

Illustration 1: a mutual deterrence standoff

A specific type of equilibrium occurs when two opponents are locked into a mutual deterrence situation. In gangster and Western movies, it takes the form of a “Mexican standoff” with opponents aiming guns at each other. In international relations, nuclear deterrence between powers capable of devastating retaliation has the same structure.

It is easy to represent such situations with the logic of a Prisoner’s Dilemma: both sides would be better off if neither threatened the other, but whatever one side does, the other has incentives to keep its guard up, either for protection or to gain advantage if the other side lowers its guard.

Kant’s categorical imperative would suggest adopting the behaviour we would like everyone to adopt. Since mutual peace is the best outcome, I should “rationally” lower my guard.23

Any experienced movie watcher will tell you that lowering your guard in a Mexican standoff is usually a terrible idea. It does not cause the other person to lower his guard. It leads you to be his prisoner or to end up dead. In international relations, few people find the suggestion that the United States should have unilaterally disarmed during the Cold War plausible. Indeed, Ukraine’s abandonment of nuclear weapons on its territory in 1994 did not lead others to do so, but instead allowed Russia to invade it a few decades later in a war that led to hundreds of thousands of deaths.

Illustration 2: the Nader-Gore choice in 2000

Suppose you are a progressive-minded voter in the United States in the year 2000. You can choose between two candidates: the Green Party’s Ralph Nader and the Democrat Al Gore. Suppose you believe Nader has the best policies. The categorical imperative tells you that you should vote for him because, if everybody voted for him, the United States would be a better place.

The difficulty is that Nader, at around 3% in the polls, had little chance of winning. Gore, on the other hand, was in a very close race with George W. Bush. In that setting, voting “on principle” for Nader might not affect Nader’s prospects, but it could contribute to Bush defeating Gore.

In the end, this is roughly what happened. The result was decided in Florida, where Bush won by only 537 votes, while 97,488 votes were cast for Nader in that state. This is one of many examples where people doing “the right thing” while ignoring what others plan to do end up with worse consequences all around (from the perspective of the people making the decision).24

Here is how some Nader voters later described their choice:

At the time, I thought I was making a principled stand, but it’s a vote I have come to regret. — Josh Brodesky25

Then that night I really regretted it. I was in Pennsylvania too, so it’s like a consequential vote. — A radio talk show caller26

Smoking is not the worst choice I made that year. I voted for Ralph Nader. — Rachel Combe27

Kant’s argument that it is individually rational to behave in this way does not hold up. The categorical imperative has intellectual appeal, largely because it resonates with our contractarian intuitions about what rules could be shared. But those intuitions are not answering Kant’s question. Kant is not asking how we should choose rules together, but what each person should adopt for themselves. By asking us to behave best not in the world as it is but in the world as it should be, Kant’s categorical imperative risks asking us to behave in an irresponsible and deluded manner.

Modern thinking about rationality, as developed by game theorists, allows us to scrutinise Kant’s claim more sharply. His idea that the categorical imperative follows from rationality does not survive that scrutiny. On this point, Binmore concludes that once one gets past the difficulty of reading Kant:

Kant’s assertion that one should honor this principle for rational reasons is conjured from the air. — Binmore (2005)

No unconditional oughts

Kant’s biggest claim in moral philosophy is that sheer rationality generates an unconditional ought: I ought to follow the categorical imperative simply because I am a rational being.

The idea of an unconditional ought may feel especially attractive in societies shaped by Judeo-Christian heritage, where moral rules were long presented as commands imposed from above by a divine being. Without the appeal to such a being, many philosophers, including Kant, tried to retain the idea of unconditional obligation. But we have seen that Kant’s attempt fails: his categorical imperative does not follow from rationality.

Modern theories of rational choice provide a clearer foundation for what “ought” can mean. Rationality is always about doing the right thing to achieve what one wants to achieve (whatever it is). In that sense, we can talk about “oughts”, but only as conditional oughts: IF I want to achieve my goal A, THEN I ought to take action B.

When people interact, these conditional “oughts” must incorporate what others are likely to do. Any stable pattern of social interaction between rational agents will take the form of a Nash equilibrium: people persist in their behaviour because it is best for them given what others are doing, and this must be true for everyone.

In line with the Humean tradition, morality can be understood as a set of cultural conventions that regulate social interactions. Their features have been selected over time because they help realise gains from cooperation. These conventions are equilibria and therefore self-enforcing. In a society with functional moral rules, it is often in each person’s interest to follow them in order to avoid social sanctions. Hence, there is a conditional ought: IF one wants to remain an accepted member of society, THEN one must abide by the moral rules of that society.

This answer is often described as underwhelming, but that is partly because it is an ultimate explanation: it explains what morality is at a fundamental level. It does not necessarily match our moral experience. To understand how morality feels from the inside, we need a proximate explanation: an account of the emotions and intuitions that guide us. We have evolved a moral sense that helps us navigate social life. In the same way that fear or hunger pushes behaviour in directions conducive to survival, social emotions such as guilt and empathy help us manage cooperation, conflict, and reputation. As a result, we do not experience moral decisions as interest-driven. We often experience them as the requirement to do what is right, and the fear of doing wrong when we violate a rule. Paradoxically, those proximate feelings may also make the ultimate explanation of morality feel disappointing. But our intuitions should not determine what we accept as the best theory.

I have the intuition that the world is solid and well-defined. I also find the picture of nature provided by quantum theory unintuitive and unappealing. But IF I want to navigate the world successfully, THEN I ought to accept the best theory available. From that perspective, the contractarian theory of morality, particularly as articulated by Ken Binmore, is the best available in its ability to account for what morality is, how it works, and how it evolves.28

Kant’s figure looms large in Western philosophy. His attempt to found morality in sheer rationality seems deep and impressive. But discussions of rationality are complex and easily confused. With two centuries of work in decision theory and game theory behind us, we can move beyond Kant’s daunting prose and identify what is wrong with his argument. The categorical imperative encourages us to behave best in the world as it should be, not in the world as it is. In many situations, that is not a sensible guide to individual choice. It can lead us to act in ways that fail to achieve what we want, and sometimes in ways that worsen outcomes for others. It is not clear in what sense this is either rational or moral.

One way to place Kant’s morality in the history of ideas is as a rearguard attempt to retain, in secular form, the absolutist flavour of Judeo-Christian moral obligation. The view I defend in this series is that Hume’s alternative was fundamentally right: morality can be understood as emerging from a social contract, an implicit agreement about how to behave properly in society. Game theory helps us understand the logic underlying social interaction and, in doing so, helps us develop a theory of morality that fits our practices and beliefs. Unlike Kant’s views, this theory is stripped of mysterious content and does not require us to assume the existence of absolute moral principles of some kind that we would have to discover.

Having located this approach within the big questions of moral philosophy, I will develop it in detail in the next few posts.

References

Binmore, K. (1994) Game Theory and the Social Contract, Volume 1: Playing Fair. Cambridge, MA: MIT Press.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. Cambridge, MA: MIT Press.

Binmore, K. (2005) Natural Justice. Oxford: Oxford University Press.

Gilboa, I. (2009) Theory of Decision under Uncertainty. Cambridge: Cambridge University Press.

Guyer, P. (2017) ‘Kant’, in Zalta, E.N. (ed.) The Stanford Encyclopedia of Philosophy (Summer 2017 Edition). Stanford: Metaphysics Research Lab.

Hume, D. ([1751] 1998) An Enquiry Concerning the Principles of Morals. Oxford: Oxford University Press.

Kant, I. (1797) ‘On a supposed right to tell lies from benevolent motives’.

Kant, I. ([1785] 2017) Groundwork of the Metaphysics of Morals. Translated by J. Bennett. Early Modern Texts.

Page, L. (2022) Optimally Irrational. Cambridge: Cambridge University Press.

Quattrone, G.A. and Tversky, A. (1984) ‘Causal versus diagnostic contingencies: On self-deception and on the voter’s illusion’, Journal of Personality and Social Psychology, 46(2), pp. 237–248.

Riker, W.H. (1962) The Theory of Political Coalitions. New Haven, CT: Yale University Press.

Russell, B. (1945) A History of Western Philosophy. London: George Allen & Unwin.

Weber, M. ([1919] 1948) ‘Politics as a vocation’, in Gerth, H.H. and Mills, C.W. (eds) From Max Weber: Essays in Sociology. London: Routledge & Kegan Paul, pp. 77–128.

13

As I wrote in a previous post:

Proposed political solutions that assume everyone will simply “do the right thing” are a red herring. A central challenge in political theory is that people typically do not all just want to do what might be in the best from a collective point of view.

Last November, I wrote that the possible election of Donald Trump was a risk for the quality of US democratic institutions. Unfortunately, it is now clear that the first year of this administration has far exceeded such negative expectations.

One aspect where the Trump administration has been especially destructive is the US-led rule-based international order. It is an order the US largely built after 1945, and one from which it has benefited disproportionately, through a dense web of rich allies that extend American geopolitical reach. Over the last year, the US administration has echoed Russia’s narrative about its war in Ukraine and pushed for a deal that would require Ukraine to give up parts of its territory, and it has treated Europe aggressively, from the imposition of tariffs to threats over Greenland.

In the last few days, Trump has again refused to rule out taking Greenland by force.2 In a recent CNN interview, White House Deputy Chief of Staff Stephen Miller defended this posture in blunt terms:

[W]e live in a world, in the real world that is governed by strength, that is governed by force, that is governed by power.

Miller is, like so many professed “international realists”, too smart by half.3 It is true that in international relations, there is no global government and no global police to enforce rules in the way domestic law is enforced. But those who conclude from this that the world is simply a Hobbesian free-for-all are misguided about the strategic nature of international relations.4

Even without an external enforcer, countries typically negotiate a modus vivendi: a set of conventions that stabilise expectations and make cooperation possible. They do not do this because they are idealists. They do it because cooperation is mutually beneficial when it is sustained over time. A forceful seizure of Greenland would not be “realism”. It would be short-sightedness: an action that gains little, and risks breaking the conventions that underpin America’s alliances and its long-run power.

Scenario for a takeover

Let’s consider what would happen in the case of an attempt at a military takeover of Greenland. Would it be politically possible for the administration to do so within US institutions? And, if it happened, what would the geopolitical costs be for the US?

Read more

In a 2015 US poll, 65% of American adults agreed that “every culture must determine what is acceptable morality for its people.”1 And in a 2023 survey, 60% of “Gen Z” respondents agreed with the idea that what is morally right or wrong depends on what an individual believes.2

In academia, this view is quite prevalent in some parts of the social sciences, like anthropology. In 1887, Franz Boas, one of the founders of the discipline, wrote in the journal Science:

It is my opinion that the main object of ethnological collections should be the dissemination of the fact that civilization is not something absolute, but that it is relative, and that our ideas and conceptions are true only so far as our civilization goes. — Boas (1887)

I have argued that morality emerges from social conventions and that a society’s moral system can be seen as a social contract, implicitly agreed upon by all to coordinate and cooperate. This view is often labelled Humean constructivism, as it was first put forward by Hume. Its proponents, like Robert Sugden and Ken Binmore, also use the label contractarian, since these social conventions can be described as a social contract, implicitly agreed upon by all.3

In this post, I address a criticism often levelled at this approach: it is “relativist”. With this term come accusations like these: If morality is just conventional, isn’t it the case that some societies can land on conventions we would find abhorrent, like infanticide, slavery, or genocide? In that case, would we not just have to accept these practices as fine?

The point I make here is that contractarianism is relativist in the technical sense used in metaethics, but not in the way the term is usually understood in everyday debate.

What “relative” means here

In metaethics, the branch of philosophy studying the foundations of moral claims, relativism is defined as the belief that there is no absolute moral truth. The Stanford Encyclopedia of Philosophy defines this viewpoint as:

The truth or falsity of moral judgments, or their justification, is not absolute or universal, but is relative to the traditions, convictions, or practices of a group of persons.

Under this definition, it is clear that a contractarian view is relativist. In a contractarian position, moral claims can be true or false, but only within a given moral system, a specific social contract. As a result, a moral claim that is true in one moral code can be false in another.4

Philosophers usually do not like moral relativism.5 To be frank, I do not like the term either because it is too often understood as meaning some sort of nihilism. The contractarian approach focuses on explaining the reality of moral rules and moral practices as part of a social contract, not on denying any relevance to moral considerations.

Can we condemn slavery/infanticide? Yes, in three coherent ways

There are many strands of moral philosophy that can be described as “relativist”. For some of them, which I would label “radical relativism”, different cultures cannot be compared in any way.6 This conclusion is not one that follows from the contractarian perspective I am presenting.

From within our own moral preferences

The contractarian position implies that there is no higher moral ground outside societies upon which we can stand to judge them, but it does not mean we are not entitled to our own preferences. Binmore, who, unlike me, is happy to defend the term relativism, says about it:

Moral relativism does indeed deny that it makes sense to say that one social contract is better than another in some absolute sense. But moral relativists nevertheless have their own opinions about the kinds of social contract they think desirable — Binmore (1998)

Nothing prevents us from liking or disliking another country’s practices based on our own moral preferences. Some of our fundamental moral preferences might have been shaped by evolution and be universal across cultures, while others are culturally acquired via education and socialisation.7

From an international social contract

Some (limited) order exists at the international level. In their interactions, countries follow norms that are both implicit (e.g. diplomatic usage) and explicit (e.g. international law established in treaties). These rules create a meta-normative system. While this normative system is largely silent on how countries handle matters within their borders, it does impose some constraints on practices that many states have come to view as among the most abhorrent.

Genocide is explicitly prohibited by the 1948 Genocide Convention of the United Nations, which states that it is “a crime under international law” and obliges states to prevent and punish it. The International Criminal Court has jurisdiction over genocide under the Rome Statute.

Slavery is prohibited under the 1926 Slavery Convention and the 1956 Supplementary Convention, which commit states to abolish slavery and suppress slavery-like institutions and practices.

Infanticide: International law does not use the term “infanticide”, but it protects children’s right to life. For example, the Convention on the Rights of the Child recognises every child’s “inherent right to life” and requires states to ensure the child’s survival and development.

It is important not to overstate the meaning of these international rules. International law is too often presented as an absolute yardstick of right and wrong. Instead, it is again a convention (between states). And this convention works only to the extent that the balance of states’ incentives limits infringements. A state willing to violate these rules and willing to face the negative consequences can do so.8

By outcomes and stability

Perhaps most importantly, different social contracts can be compared in terms of their practical consequences. Social contracts’ function is to regulate cooperation and conflict between members of society. Efficient moral systems can induce higher levels of cooperation and therefore higher welfare in society.

It is perfectly reasonable to compare moral norms to the extent that some can lead to better social outcomes than others. Consider, for instance, the driving rules in Singapore and Cairo. These rules are both formal (likely fairly similar in both countries) and informal, in particular, what people consider acceptable to do (how often to honk, how much to respect the rules, how gracious to be). Singapore driving norms seem unambiguously better, in the sense that they appear to be associated with less driving chaos and better driving times.9

Once again, this aspect should not be overstated. First, such a criticism is not made from a higher moral high ground, and it does not assume that “efficient cooperation” is a good that should be pursued as an absolute moral goal. Instead, this criticism can be made from the point of view of the society concerned. Saying that the Singapore equilibrium is better than the Cairo equilibrium is saying that Cairo dwellers would themselves prefer to live with the Singapore equilibrium if they could switch to it as a society. Second, efficiency does not a priori preclude some practices in other societies that we find abhorrent in ours.10

How moral realists use “relativism” as slander

Moral realists, lacking a settled account of what absolute moral truths are and how we would know them, often resort to dismissing scepticism towards moral realism with what Binmore calls “emotive slander”. They use the label “relativism” to accuse non-moral realists of supporting a vision of reality where things we find abhorrent, like infanticide and slavery, are fine.

I have been accused of holding that pedophiles are justified in disregarding the law when pursuing their claim that prepubic sex is good for children. Similarly, relativists supposedly see nothing wrong in keeping slaves or wife-beating, since both activities have been endorsed as morally sound by past societies. — Binmore (1998)

The contractarian view is not that these things are OK. It is that there is no external moral rule book that conveniently provides us with the rules on how to behave to be Right or to do Good. Instead, we hold our morality in our own hands. As social groups, we have to agree on how to work with each other to facilitate cooperation and resolve conflicts. Morality is fundamentally about adopting a social contract, an agreement about how to organise social life. “Correct” social rules are not written in the fabric of the universe; we are on our own and in charge of our own rules.11

What the “relativism” in contractarianism is not

I have indicated that the contractarian approach is relativist in the technical sense used in metaethics. However, the word “relativism” is loaded with different meanings. It is useful to make clear what the versions of this term that contractarianism does not endorse.

Not subjectivism

A frequent interpretation of moral relativism is subjectivism, which can be summarised by the idea that everyone has his or her own truths. This idea does not reflect how morality works in real life, and for a contractarian, it is logically inconsistent.

[M]oral subjectivism is absurd because it overlooks the fact that moral rules evolved to help human beings coordinate their behavior. But successful coordination depends on everybody operating the same moral rules. If everybody in a society made up their own standards, there wouldn’t be any point in having moral rules at all. — Binmore (2005)

If moral views were just things that can differ in each of our heads, how would they work? Why would Alice care when Bob tells her she is wrong, according to his own principles of morality? Why should she grant this claim more significance than if Bob were pointing out that he prefers chocolate ice cream, contrary to her choice of vanilla flavour?

Not relative to “culture”

A slight variant of subjectivism is that morality is just a characterisation of a culture in the sense that people from different cultures have different ideas.

The view of morality as convention requires more than morality being about ideas in people’s minds: moral rules must be equilibria in social games played in a given social setting. This requirement means that if people from different cultures live together in a given society, each cultural group cannot have its own morality. The idea that cultures can simply coexist side by side with their moral code in a society is as misguided as the subjectivist idea that people can live side by side with their idiosyncratic moral views.

Let’s take a simple example. Consider a society in which two groups have internalised different cultural expectations about queues. One culture treats strict queueing as a basic rule of fair access: first come, first served. The other group treats the “queue” as more of a loose signal, with access negotiated through persistence and a bit of elbow-work. If you queue diligently among people in that group, you may find that they move ahead of you without treating this as a serious breach of conduct.12

Imagine that, because cultures are said to be “equal” and not assessable from outside, members of the second culture are permitted to ignore the queue when interacting with everyone else. This would not lead to the peaceful coexistence of two norms in the same shared space. It would more likely unravel the queueing equilibrium altogether: once compliance is no longer common knowledge, people in the first culture lose the incentive to keep queuing, and the institution stops doing its job.

Obviously, a society could not work if groups could have their own moral codes. A society requires an overarching moral system that regulates interactions between all members of society.13

Not all cultures are “equal”

Perhaps the most common version of relativism outside of academic philosophy is the idea that different cultures cannot be compared and judged from the point of view of other cultures. In practice, this goes with the idea that each culture is equal and that every culture should be respected. This question has taken a political aspect, with right-wing thinkers often praising Western culture and institutions as superior to the culture of some other countries, sometimes described as backward. In opposition to this view, some left-wing thinkers argue that all cultures are equally worthy of respect. This view is, perhaps understandably, often promoted in international bodies. The UNESCO Declaration on Cultural Policies (1982) stated, for instance, that

The equality and dignity of all cultures must be recognized, as must the right of each people and cultural community to affirm and preserve its cultural identity and have it respected by others.

The idea that all cultures are equal in worth is, in fact, unfounded in a contractarian perspective. While using the term “relativist” for his position, this is what Binmore says here:

The basic misunderstanding is that traditionalists think that to refuse to label a Society as Wrong or Bad is to say that all societies are equally Right or Good. But a relativist finds no more meaning in the claim that two societies are equally Good than he does in the claim that one is Better than the other. — Binmore (1998)

And he adds:

[T]he wishy-washy liberal doctrine that all societies are equally meritorious receives no support from naturalism. — Binmore (1998)

Not postmodernism

Finally, an important point to make is that saying that there is no absolute moral truth is not saying that there is no objective reality out there. The idea that refusing the absolute truths of moral claims is like rejecting the objectivity of reality is like saying that if one claims that there are no absolute rules of football written in the fabric of the universe—these rules being human conventions—one must be denying that the football pitch, the ball and the players really exist.

Contractarianism is therefore not a bedfellow of postmodernism and its often sceptical claims about the existence of universal truths that can be studied through reasoning and empirical observation.

Moral relativists believe that moral facts are true because they are generally held to be true within a particular culture. Postmodernists claim to believe that the same holds for all facts. A postmodernist must therefore be a moral relativist, but nothing says that a moral relativist must be a postmodernist. For example, I am as premodern as it is possible to be, but I am nevertheless a moral relativist. — Binmore (2005)

On that front, Binmore, I, and other contractarians are firmly on the side of rationalism. When considering postmodernism, whose wordplay often tiptoes around suggestions that the notion of external reality is a fallacy, I would use this famous view from Bertrand Russell:

This is one of those views which are so absurd that only very learned men could possibly adopt them. — Russell (1959)14

Reform

The fact that we can compare moral rules in terms of their outcomes and stability should make it clear that contractarianism does not prevent reform from happening. A big question about institutions is their ability to organise social cooperation successfully. It is clear that some institutions are more effective at this than others. In his book The Origins of Political Order, Francis Fukuyama describes this difference between institutions with “Denmark” being used as an example of having highly successful institutions.

The problem of creating modern political institutions has been described as the problem of “getting to Denmark;’ after the title of a paper written by two social scientists at the World Bank, Lant Pritchett and Michael Woolcock. For people in developed countries, “Denmark” is a mythical place that is known to have good political and economic institutions: it is stable, democratic, peaceful, prosperous, inclusive, and has extremely low levels of political corruption. Everyone would like to figure out how to transform Somalia, Haiti, Nigeria, Iraq, or Afghanistan into “Denmark,” and the international development community has long lists of presumed Denmark-like attributes that they are trying to help failed states achieve. — Fukuyama (2011)

It would be very reasonable for people living in countries that do not benefit from such a mix of institutions to argue in favour of political reform to get closer to “Denmark”. Here again, the argument is simply about the agreement of the people involved: proposing a move towards more effective institutions is proposing something people would have an interest in agreeing to. Binmore makes a plain case for this logic with the example of the switch of driving side in Sweden in 1967.

A real-life instance of the driving example may help. Sweden switched from driving on the left to driving on the right on September 1st, 1967. If I had been a Swede before this decision was made, I would have lent my voice to those advocating the change. Since relativists hold that it was wrong to drive on the right in Sweden before September 1st, 1967, and wrong to drive on the left afterwards, the words bad or wrong would have been useless to me when urging reform. It might have helped the cause to argue that driving on the left is intrinsically Bad or Wrong, but it would be intellectually dishonest for a relativist to take this line. Still less would I have argued that Swedish citizens should be left to make their own subjective judgments when choosing on which side of the road to drive. I would simply have argued that enough Swedes would benefit from driving on the same side of the road as the rest of continental Europe to make it worthwhile for us all joining together to get the reform adopted. — Binmore (2005)

So the key point is that calls for reform cannot be made from an appeal to morality, since the grounds for moral agreement are being negotiated in the process of reform.

[W]hat would it then mean to say that our current social contract is itself unfair? One must either accept that the relativism implicit in a naturalistic approach to ethics makes the question incoherent, or else abandon oneself to one or other of the traditional metaphysical notions of justice about which evolution cares not a whit. — Binmore (1998)

Nonetheless, in practice, moral language is often part of the bargaining and mobilisation that makes a new agreement possible. Requests for reform are bids to change the social contract at the societal level. Proponents can have strong moral feelings about it for two reasons: first, because of their deep moral preferences, and second, because of the moral preferences in the social group they belong to. An example of such positions is how opposition to slavery appeared from the start, within slave-owner societies in the West, as conflicting with deep feelings about respect for other humans and with the moral principles of religion.15

If successful, the rule change they defend will come to define what counts as right and wrong in society. There are only a few steps from thinking “it should be right/wrong” to feeling that “it is Right/Wrong”, especially when people have strong moral feelings about it.

Yet recognising that such appeals to external truths are ungrounded, and that we hold our morality in our own hands, can be liberating. It allows us to think more clearly and freely about how we want our society to be organised, instead of chasing the “Right” way in some mysterious metaphysical reality.

The present post has mostly been about defending the contractarian approach from the different accusations associated with the term relativism. A common argument put forward by moral realists is that it would lead us to accept practices that we find abhorrent, like slavery and infanticide. Given the strength of our moral feelings against such practices, it would be a very unappealing conclusion. However, as I have explained here, contractarians are not in any way bound to say that they find such practices fine. Like most people living today, they would typically prefer a world without them.

Having said that, it is worth pointing out that the moral realist position with this argument is much weaker than it seems. First, the fact that some conclusions might seem appalling is not a reason to reject a theory. Theories like heliocentrism or evolution seemed appalling to many when they were proposed, it did not make them wrong.16 The importance moral realists give to moral intuition as evidence is all the more dubious given that we can observe societies at present and in the past differing markedly in moral intuitions.17

Second, moral realists do not agree on a common theory of what absolute moral truths are and where they come from. They do not even agree on a common method to answer this question. If you take a naturalistic perspective, this persistent disagreement is not surprising. It has a simple explanation: moral realists are like ancient astronomers looking into epicycles to understand the movement of planets. They have a wrong starting assumption: there are some absolute moral principles out there for us to find.

This brings us back to the point I made earlier in this series of posts: because they aim to found morality in an absolute way, moral realists have to assume some skyhook at some point, to found their theory of morality on an “unconditional ought”: “I must do good because something is morally good and must be done”, full stop. This assumption that some abstract, immaterial principle has some kind of force on material beings like us is strange and, as famously pointed out by John Mackie, unlike anything produced by scientific knowledge. The appeal of such an idea might be particularly prominent in societies with a Judeo-Christian heritage, where an all-powerful moralising God has shaped our moral intuitions for centuries.

The contractarian approach sidesteps this metaphysical difficulty and the use of skyhooks to found morality. Instead, it posits that morality arises from something grounded in reality: a social agreement about how to organise social interactions.

References

Binmore, K.G. (1998) Game Theory and the Social Contract, Volume 2: Just Playing: Economic Learning and Social Evolution. Cambridge, MA: MIT Press.

Binmore, K.G. (2005) Natural Justice. Oxford: Oxford University Press.

Boardman, A.E., Greenberg, D.H., Vining, A.R. and Weimer, D.L. (2018) Cost-Benefit Analysis: Concepts and Practice. 5th edn. Cambridge: Cambridge University Press.

Boas, F. (1887) ‘Museums of Ethnology and Their Classification’, Science, 9(228), pp. 587–589.

Disraeli, B. (1864) Speech at the Oxford Diocesan Conference (25 November 1864), quoted in Monypenny, W.F. and Buckle, G.E. (1929) The Life of Benjamin Disraeli, Earl of Beaconsfield, Vol. II: 1860–1881. London: John Murray.

Fukuyama, F. (2011) The Origins of Political Order: From Prehuman Times to the French Revolution. New York: Farrar, Straus and Giroux.

Gowans, C. (2021) ‘Moral Relativism’, in Zalta, E.N. (ed.) The Stanford Encyclopedia of Philosophy (Spring 2021 Edition). Stanford, CA: Metaphysics Research Lab, Stanford University (Accessed: 3 January 2026).

Harman, G. (1975) ‘Moral Relativism Defended’, The Philosophical Review, 84(1), pp. 3–22.

Holland, T. (2019) Dominion: The Making of the Western Mind. London: Little, Brown.

Hrdy, S.B. (1999) Mother Nature: A History of Mothers, Infants, and Natural Selection. New York: Knopf.

Hume, D. (1751) An Enquiry Concerning the Principles of Morals. London: A. Millar.

International Criminal Court (1998) Rome Statute of the International Criminal Court. Rome, 17 July 1998 (entered into force 1 July 2002).

League of Nations (1926) Slavery Convention. Geneva, 25 September 1926 (entered into force 9 March 1927).

Mackie, J.L. (1977) Ethics: Inventing Right and Wrong. Harmondsworth: Penguin Books.

MacCulloch, D. (2009) A History of Christianity: The First Three Thousand Years. London: Allen Lane.

Melanchthon, P. (1549) Initia doctrinae physicae dictata in academia Vuitebergensi. Wittenberg: Johann Lufft.

Pritchett, L. and Woolcock, M. (2004) ‘Solutions when the solution is the problem: Arraying the disarray in development’, World Development, 32(2), pp. 191–212.

Russell, B. (1959) ‘Face to Face’ (television interview with John Freeman), BBC Television, 4 March.

UNESCO (1982) Mexico City Declaration on Cultural Policies (World Conference on Cultural Policies, Mexico City, 26 July–6 August 1982). Paris: UNESCO.

United Nations (1948) Convention on the Prevention and Punishment of the Crime of Genocide. New York: United Nations, 9 December 1948 (entered into force 12 January 1951).

United Nations (1956) Supplementary Convention on the Abolition of Slavery, the Slave Trade, and Institutions and Practices Similar to Slavery. Geneva: United Nations, 7 September 1956 (entered into force 30 April 1957).

United Nations (1989) Convention on the Rights of the Child. New York: United Nations, 20 November 1989 (entered into force 2 September 1990).

Williams, E. (1944) Capitalism and Slavery. Chapel Hill, NC: University of North Carolina Press.

A poll of modern philosophers suggests that a majority of them are moral realists.1 They assume that morality is objective in the sense that there are moral truths that exist independently of what people might think about them. This view is, interestingly, at odds with the origin of the term “morality” which points to social conventions.

[E]tymologically, the term “moral” comes from the Latin mos, which means custom or habit, and it is a translation of the Greek ethos, which means roughly the same thing, and is the origin of the term “ethics”. — Stanford Encyclopedia of Philosophy (2019)

In line with this etymological origin, I argue that the best explanation of morality is that it emerged to regulate cooperation and coordination in social interactions, and that moral systems are social conventions. This naturalistic approach starts from the factual observation that people have partially but not fully aligned interests, leading to social interactions that mix cooperation and conflict.

This view eliminates the need to posit unobserved moral truths for moral rules to mean something. Moral rules can be understood as commonly agreed rules of social interaction among members of society. These rules feel deep and fundamental because they govern the most important game we play: the Game of Life. The idea that moral rules in a society are agreed upon is often reflected in the use of the term “social contract” to describe them. People learn these rules through education and socialisation.

In this post, I address criticisms levelled at this view of morality as the reflection of a social contract.

The guilt trap

One often hears the suggestion that if morality is only conventional, it is meaningless.2 We are then told that if moral claims have no meaning, anything goes. Some of the worst things we can think of—like killing innocent people—must be “fine” and nothing compels criminals to behave well.

The leap from “conventional” to “anything goes” is a mistake, and I’ll explain why in the next section. But I’ll start by criticising this style of counterargument, which I’ll label a guilt trap. It is a trap because it is another version of the Santa Claus fallacy. It is saying something like: “do you realise the awful implications of your beliefs”?

In fact, even if a theory were to lead us to very distasteful conclusions, that would not be a reason to reject it. Suppose that—ghastly horror—we were to find that our home, Earth, is not the centre of the universe, but just a tiny dot rotating around an average star, somewhat on the skirt of a galaxy comprised of about 100 billion stars, itself one among billions of galaxies. Too bad. Reality is not determined by our preferences. A Humean constructivist can therefore stand firm on rejecting the guilt trap because it is not a good argument to begin with.

But because the human brain is designed to argue in favour of our preferences, it might nonetheless be a useful rhetorical move for the Humean constructivist to point out that nothing fundamentally ghastly should be expected from this approach. The goal of Humean constructivism is to explain morality—practices and beliefs—as it is observed in real life. Hence, a Humean constructivist is more likely to explain why our current moral practices often make sense than to advocate throwing them away in favour of views we find abhorrent.3

Morality as the respect of a social contract

Moral systems as social contracts

The first point to make is that saying there are no absolute moral truths is not the same as saying moral claims are meaningless. A contract sets rules defining rights and duties between those who sign it. The rules created by a contract do not come from “out there”. They arise from an agreement between different parties. Saying that morality emerges from commonly agreed rules—conventions—about how to behave in society does not imply that these rules are meaningless or can be ignored at will.

Imagine Alice and Bob start playing tennis. At some point, Alice hits a perfectly good forehand that lands 1 m within the court. Bob yells “out” and claims the point. Alice is entitled, by the rules of the game, to say “you are wrong, Bob, you lost the point”. This claim is not “meaningless”. It is true, given the rules of tennis.

We can agree that the rules of tennis are conventional. They are neither written into the fabric of the universe nor implied by the rules of pure logic. Does it follow that, because they are conventional, Bob can simply ignore them? The answer is simple and non-mysterious: it is a matter of fact that Bob might choose to ignore the rules and claim he won the point even though he did not. But if he does so, he violates the implicit understanding he had with Alice that he would play fair, that is, play by the commonly agreed rules. Faced with an outright disrespect of the rules, Alice is likely to fire back: “fine, I am not playing with you anymore”. The rules of tennis are a social contract between players. Bob cannot violate this contract and expect Alice to continue playing while ignoring his violations.

The word social contract can seem grand. Past philosophers sometimes implied, like Hobbes, that there might have been a time when people literally sat down to agree on a social contract. These stories are clearly fictitious. In his discussion of the origin of state institutions, Francis Fukuyama points out that early states pretty much never formed that way:

We might label this the Hobbesean fallacy: the idea that human beings were primordially individualistic and that they entered into society at a later stage in their development only as a result of a rational calculation that social cooperation was the best way for them to achieve their individual ends. — Fukuyama (2011)

Such fairy tales about social contracts are not necessary. A social contract can be understood as a commonly agreed understanding of how things should be done, and what would count as a breach of acceptable behaviour in society. To be clear about how he uses this expression, Binmore writes:

This section has identified a social contract with an implicit self-policing agreement between members of society to coordinate on a particular equilibrium in the game of life. Some apology is appropriate for those who find this terminology misleading. […] Words other than contract—such as compact, covenant, concordat, custom, or convention—might better convey the intention that nobody is to be imagined to have signed a binding document or to be subject to pre-existing moral commitments. Perhaps the best alternative term would be “social consensus”. This does not even carry the connotation that those party to it are necessarily aware of the fact. — Binmore (1994, emphasis mine)

If morality emerges from conventions, in what sense “ought” we to abide by moral rules? The answer is that we ought to abide by moral rules to be able to continue to play in social games with others, and to remain accepted as a player by them. If we violate that social contract, we lose our right—as defined by the social contract—to be treated as a rule-abiding player, and we risk a range of sanctions. In the extreme, we might be thrown out of the social game entirely, ending up in prison or worse.4

People sometimes react to this explanation by saying: this is not a proper “ought”. This claim tends to take two forms. First, there are rules you really ought to follow, even if you would face no social sanctions for not doing so. Second, there are things that are really bad, whatever people think about them, like “killing innocent people”.

The ring of Gyges

Let’s first address the idea that morality must imply a duty to do something beyond the costs and benefits set out in the social contract. This question was already discussed in Plato’s Republic, where Glaucon counters Socrates’ idealism with a story about what happens when we gain impunity. In the story, a shepherd named Gyges finds a ring that lets him become invisible at will. Once he realises he can act without being seen, he uses the ring to enter the palace, seduce the queen, kill the king, and take the throne.

Glaucon concludes:

[E]very man, when he supposes himself to have the power to do wrong, does wrong.

For Glaucon, we follow moral rules only because we have an interest in doing so. Remove the incentives to behave well, and we would stop doing so. This view is not necessarily in line with our intuitions. Plato uses Glaucon’s view to criticise it and argue that there is more to being moral: morality comes from within us, and being moral is necessary to be at peace with oneself and happy.

From a Humean constructivist perspective, Glaucon’s argument seems, unfortunately, somewhat sound. In the end, a social contract works only if it creates incentives for people to follow it. Binmore even points out that assuming we have a moral sense that reliably drives us to behave against our interest would conflict with the logic of evolution:

[I]f the morality of everyday life required people to take actions that made them less fit, how could it have evolved? […] one of the achievements of modern social psychology has been to expose the gap that lies between how we like to think of ourselves and the reality of what we actually are. […] realism requires that we take the same attitude to how society actually works as Oliver Cromwell took to his appearance. He too would have liked to look better, but he nevertheless insisted on being painted “warts and all”. — Binmore (1998)

What is the meaning of words like right or wrong and ought

How should we think of Gyges’ actions, if morality is seen as the reflection of a social contract?

First, it is perfectly coherent to say that what Gyges is doing is “wrong”, given the social contract of his society. Rules of social contracts do not say “don’t do that except if nobody is watching.” Rules are meant to be obeyed, whether there are observers or not. It is unlikely that the excuse “Sorry, officer, I thought nobody was watching” has ever been successful in evading a speeding ticket.

Second, it is coherent to say that Gyges “ought” to avoid doing all the bad things he does. He ought to play by the rules of the social contract if he wants to remain entitled to be treated as a good social partner by other people. If he behaves badly and he is found out, for instance, if he drops his ring, he would face the consequences.

But wait, you might say: “what if there is a 0% chance that he would be found out, and therefore no reason for him not to behave badly?” Here, the Humean constructivist resists the pressure to invent a skyhook: a moral duty that exists above and beyond the social contract and somehow binds Gyges to behave well in all circumstances. If there are absolutely no penalties for violating the rules of the social contract, there is no additional force, external to the social contract, that would give Gyges an injunction to respect it.

Note that this does not mean Gyges is permitted by moral rules to behave badly. The observation that motorists can (and sometimes do) speed when there is no police around does not mean that this action is condoned by the driving code.

Explaining the role of moral intuitions in social interactions

These answers, while very clear and coherent, face the challenge of our moral intuitions: we feel that cheating when unobserved is bad. Here, however, we should not treat these intuitions as a window into moral truth. A naturalistic approach should instead explain why these intuitions exist and why they take the form they do.5 The answer is that evolution endowed us with a moral sense that helps us play social games well. As I said in the previous post:

Our moral sense, shaped by eons of evolution, is designed to provide us with emotions that help us play the Game of Life successfully. Any deviation from the moral code puts us at risk of future sanctions: blame, ostracisation, and even, in some cases, violence. Our moral emotions track the costs of deviations and bring them back into our present. They embed this shadow of the future in our daily experience.6

These moral intuitions are also designed to help us assess others’ behaviour and detect violations, subtle or blatant, of the social contract. In Gyges’ case, our intuitions tell us that what he did is wrong. A social contract works to the extent that deviations are sanctioned. Members of society are required by the social contract to sanction violations of that social contract. Not doing so is a breach of the contract in the same way as not reporting a crime can be itself a crime (“misprision of felony”). It is therefore clear that upon hearing Gyges’ story, listeners like us ought to form the kind of negative moral judgement that would justify punishing him if he were found out.

What about Gyges’ feelings? Even though Gyges might face 0% risk of being found, he might nonetheless experience moral feelings about his actions: a sense of duty not to behave badly, and guilt for thinking about or doing bad things. Here, again, the answer is not mysterious. These feelings evolved to track the possible risk of being found out and the future costs involved. Even if we face a situation of total impunity, it is reasonable for such feelings to be triggered, because situations with truly 0% risk do not really exist in real life. Even the culprit in Hitchcock’s story of a “perfect murder” in Dial M for Murder ends up being arrested. Hence, we should not be surprised that our moral emotions ring alarm bells, even when it seems that no risk of being found out exists.7

Being mindful of the deceptive appeal of the term social contract

Another problem generated by our moral sense is that the term “social contract” is itself loaded. We have a duty to respect a contract in society, because every specific contract is embedded in the overarching rules of the social contract.8 There is, however, nothing above society that sustains the social contract.

The term social contract might therefore be deceptively appealing. Our intuitions may find it more palatable than the term convention. I would, however, be slightly disingenuous if I leveraged those positive intuitions to make the idea of morality as a social contract sound more convincing.

I shall emphatically not argue that members of society have an a priori obligation or duty to honor the social contract. On the contrary, it will be argued that the only viable candidates for a social contract are those agreements, implicit or explicit, that police themselves. […] — Binmore (1994, emphasis in the original)

The role of trade-offs in morality

Note that these emotions do not need to feel to us like they are tracking risk return trade-offs. We can feel strongly motivated by such feelings, and some people experience them more than others.9 In other words, the fact that our moral sense tracks risk-return trade-offs is an ultimate explanation of moral behaviour, but we often experience moral judgements as driven by strong feelings and principles that seem devoid of calculation. These feelings are the proximate explanation of our moral behaviour.10

Having said that, it would be naive to ignore trade-offs. We would like to think we would act morally in all circumstances, but the statement “The surprising thing is not that every man has his price, but how low it is,” commonly attributed to Napoleon, bites because for every Schindler willing to sacrifice his interests for moral principles, there were many more Eichmann who followed wherever institutional carrots and sticks led them.11

my hero in the Republic [is] Plato’s brother, Glaucon—who gets short shrift from Socrates for putting a view close to the social contract ideas defended in this book. I think that a modern Glaucon would be agreeing with me that fairness norms evolved to select one of the many ways to balance power in a group. — Binmore (2005)

The Humean constructivist answer to the Ring of Gyges challenge

We can therefore summarise a Humean constructivist answer to the challenge of the ring of Gyges as follows:

1. We can say that Gyges was “wrong” given the social contract.

2. According to that social contract, Gyges “ought” not to violate its rules. But a social contract that does not attach appropriate incentives to its rules will fail to be followed. If a social contract has appropriate incentives, then the rules of the social contract align with Gyges’ interests: not only should he follow them from the social contract perspective, but he also should follow them from the perspective of his own interests.

3. If Gyges violates the social contract thanks to his impunity, other members of society will have strong moral feelings condemning it.

4. Gyges might also have negative moral feelings about it (though these feelings might erode with repeated experience of impunity).

Not “anything goes”

It is easy to misread the claim that moral norms are man-made (or socially constructed) as implying that anything goes. To start with, moral norms need to be respected for society to work. A society where civility and trust disappear breaks down.

In addition, moral norms cannot take any possible shape or form. The logic of strategic interactions imposes constraints on them.

Not everything can work as a social contract

Saying that because moral norms are socially constructed, they can be anything is a bit like saying that because buildings are man-made, they can take any shape. Buildings can take many shapes, but to withstand the test of time they must respect the laws of physics. It is exactly the same for moral norms. It is obvious that they differ widely across times and places, but for them to work over long periods, they need to respect the “laws” of social interaction, so to speak. In other words, they must be compatible with the patterns of behaviour that emerge in human societies, given that individuals have partially but incompletely aligned incentives.

The idea that moral and fairness norms are equilibria of social games has a key implication. If they remain stable and respected, it is not because people are brainwashed and mindlessly obey imposed rules. Instead, social norms are stable because they are self-enforcing: everybody has an interest in following them when everybody else follows them.

Consider driving on the road in a country like the USA. Why is the rule “everybody drives on the right side of the road” respected by nearly everybody in society? One might be tempted to say it is because it is illegal not to do so. But there are many countries where it is illegal to do various things, and many people nonetheless treat the law as a flexible instruction rather than a strict rule. The real reason almost everybody drives on the right in the US is that it would not pay to drive on the left. You would most often not arrive earlier, you would risk an accident, and because nobody else does it, you would likely attract negative judgment from people around you.

Among all the possible moral codes one could conceive, only a tiny proportion are equilibria. The rule “everybody drives on the right” is not the only solution. In several countries, like the UK or Australia, the rule “everybody drives on the left” is used instead. But no country has adopted in its official driving code rules like “drive on the side you fancy” or “cars drive on the left and trucks on the right”. There are good reasons for these absences. These alternatives are not solutions to the driving game.12 Any country with such rules would find not only that they lead to bad outcomes but also that people end up not respecting them. Conventions to drive on the left or on the right would emerge anyway. Historically, for example, the convention to keep left on the road emerged in Britain as a practice long before it was formally written into national traffic law.13

Moral, legal and ethical systems are conventions, but they are not arbitrary: they are constrained by the structure of conflict and cooperation in society.

A lot of the things we find abhorrent generate such feelings for good reasons

We can expect that moral systems that survive the test of time will encode concerns for participants’ lives and physical integrity. An argument of the type “killing random people is wrong, therefore there are absolute moral truths” mistakes our proximate moral feelings—attuned to the fact that modern societies ban random killings—for evidence that there is an absolute truth “out there” about it.

A Humean constructivist, and in particular Binmore, points out that if our current rules are the way they are, it is typically because they help sustain the way our society works. In liberal democratic countries, moral systems form a social contract well-suited to support large-scale cooperation. Therefore, in addition to the fact that Humean constructivists typically share the same negative moral feelings as everybody else about ideas such as allowing random killings, they also have an additional reason to reject such radical suggestions: they would likely tear the fabric of society.14

Mainstream ethical philosophy is lost in conceptual mazes because it takes our moral intuitions at face value, as if they pointed to something “out there” that justifies our moral stances. We “ought” to do this or that because it is right or good in an absolute sense. Moral intuitions are, however, the tail that wags the dog. Starting from them to build an understanding of morality treats the proximate psychological mechanisms that help humans navigate cooperative social interactions as a primary source of insight into morality, instead of looking at the ultimate causes of morality: the logic of human cooperation, which shaped these intuitions.

Saying morality arises from social conventions, and that we can think of moral systems as a social contract, often raises the concern that nihilism would engulf society if such paltry views were to take hold. All the types of gruesome abuse we might think of would be acceptable because humans would be free to do anything.

As I have put here, it is preposterous. For sure, the readers of this post have countless times followed social conventions when playing board games, sporting matches and everyday interactions, without assuming that absolute truths reside behind the rules they followed. Similarly, moral rules must be followed for society to work. Because there is no enforcer outside society, moral rules need to be self-enforcing to be sustainable: moral systems must come with a range of formal and informal sanctions that ensure that nobody has an interest in stepping outside the rules of appropriate behaviour. Our moral intuitions are then a reflection of the fact that our cognition is well designed for us to navigate these situations, anticipate what is appropriate, be wary of what might not be, and so on.

Finally, the idea that moral systems are social contracts in no way implies that anything goes. On the contrary, it is reasonable to assume that among all the social rules we could imagine, only a tiny subset can be part of a sustainable social contract.

I expect that some readers will point out a gaping hole in my argument. Even if not all rules are permitted, there is no guarantee that some very unpleasant social contract cannot work as an equilibrium in a society. What are we to say about it then? Should we say that slavery or the subjugation of women is fine if another society seems to be stable with such institutions? This question is an important one, and it will be the topic of my next post.

References

Acton, J. (1887) ‘Letter to Archbishop Mandell Creighton (5 April 1887)’, in Acton–Creighton Correspondence.

Binmore, K. (1994) Game Theory and the Social Contract, Volume 1: Playing Fair. Cambridge, MA: The MIT Press.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. Cambridge, MA: The MIT Press.

Binmore, K. (2005) Natural Justice. Oxford: Oxford University Press.

Fukuyama, F. (2011) The Origins of Political Order: From Prehuman Times to the French Revolution. New York, NY: Farrar, Straus and Giroux.

Hare, J. (2019) ‘Religion and Morality’, in Zalta, E.N. (ed.) The Stanford Encyclopedia of Philosophy (Fall 2019 edn). Metaphysics Research Lab, Stanford University.

Lie-Panis, J. and André, J.-B. (2022) ‘Cooperation as a signal of time preferences’, Proceedings of the Royal Society B: Biological Sciences, 289(1973), 20212266.

In a note last year, Richard Dawkins asked a simple question: is morality objective? Professional philosophers often put the question this way: are there statements that are truth-apt (they can be right or wrong) and whose truth is stance-independent (whether they are right or wrong does not depend on people’s thoughts or preferences about it).

In the previous post, I argued that the answer to that question is negative: we don’t have good reasons to assume that there are moral truths “out there”. Such an answer is sometimes met with shock and possibly horror. The philosopher Rudolf Carnap reports an anecdote about how people reacted to his claim that value statements (including moral ones) do not describe facts and cannot be proved true or false. One of his colleagues even pondered whether he should call the police to put him in jail.

According to these critics, to deny to value statements the status of theoretical assertions and thereby the status of demonstrating their validity must necessarily lead to immorality and nihilism. In Prague I found a striking example of this view in Oskar Kraus, the leading representative of the philosophy of Franz Brentano. I heard from the students that in one of his seminars he characterized my thesis of the nature of value statements as so dangerous for the morality of youth that he had seriously pondered the question whether it was not his duty to call on the state authorities to put me in jail. — Carnap (1963)1

Carnap’s story captures a familiar fear: once we give up on absolute moral truths, we are left with moral chaos.

Until now, my posts on the topic have been mostly about pushing back against these widespread intuitions and against established philosophies building on them. Now is the time to flesh out more how we can think of morality from a naturalistic perspective, once we abandon the idea that there are absolute moral truths “out there”.

Locating the naturalistic position in the space of moral philosophy

For most people, ethical discussions often seem a bit mysterious. What is right? What is wrong? And how do we know how to answer these questions?

Metaethics—the branch of philosophy that looks at what morality is—can seem daunting. It is filled with abstract notions and technical terms. Early in his career, prior to producing the work that would end in his landmark book on the topic, On What Matters, Derek Parfit had purposely stayed away from that field. He is said to have told a colleague about it:

I don’t do metaethics. I find it much too hard. — Parfit2

Here, I provide a quick introduction to metaethics that breaks down the different philosophical positions based on answers to a few key questions. This makes it easier to locate where the naturalistic position I am developing here stands.3

Moral realism

The first question is the one asked by Dawkins: is morality objective? Those answering yes are “moral realists”. As I indicated in my last post, an international poll of philosophers suggests that a majority of them endorse this view. The bulk of my post was dedicated to arguing against it.

One can think of two types of justifications for such a position. The first aims to ground an objective morality in natural facts. This “moral naturalism” is the position adopted by thinkers like Peter Singer and Sam Harris.4 It starts from factual descriptions of human experience (for example, that pain is undesirable and happiness desirable). It then argues that we can take an evaluative stance on this basis (for example, that pain is “bad” not just for the person, but in some higher sense that gives us a moral duty to reduce it).

Criticism of moral realism. This introduction of an evaluative stance, not grounded in natural facts, does all the work here: it smuggles an ought into the theory. It does not show that morality is objective. It assumes it. It is a logical leap that the reader is free to make, but it is not warranted by a naturalistic approach.

The second approach is to say that reasoning itself can help us identify moral truths. This approach is labelled “robust realism”, it is the one held by philosophers like Immanuel Kant and Derek Parfit.

Criticism of robust realism. I previously discussed Parfit’s argument.5 His claim to only use reason to find moral truths is a bit incorrect. In the end, he relies on our moral intuitions as a kind of primary ground upon which to build his theory: he investigates our intuitions with thought experiments and tries to build a theory which rationalises our “reasoned intuitions” (i.e. intuitions that resist some kind of rational investigation about how right they are). The problem here is that we have a very good naturalistic account of why we would have moral intuitions, based on evolutionary explanations. There is therefore no reason to assume that the existence of moral intuitions is evidence of objective moral truths “out there”.

Moral anti-realism

Let’s assume we abandon moral realism. A question we can ask next is: ”OK, morality is not objective in an absolute way, but can moral statements nonetheless be considered true or false in another way?”

Here, one option is to say no. Moral statements are neither true nor false, because moral statements do not refer to a moral reality that can make them true or false. Instead, moral claims reflect our preferences. Hence, when we say “murder is wrong” we just mean “I really don’t like murder”. This approach, proposed by philosopher A.J. Ayer,6 is called emotivism. It is also nicknamed the boo-hurrah theory of morality. A statement like “murder is wrong” just means “boo murder” and “charity is good” just means “hurrah charity”. Our moral statements, therefore, reflect our feelings about things.

Criticism of emotivism. I see at least two issues with emotivism. First, identifying moral statements with moral feelings raises the question of why we have them and why they take the particular form they do. Could we have any type of moral feelings? Could we expect “hurrah murder” to be as likely as “boo murder” as a feeling? If not, why? Emotivism leaves this question unresolved. A second issue is that moral statements seem to have a logical structure (this is called the Frege–Geach problem).7 We can make apparently valid inferences such as “murder is wrong, so intending to murder is wrong” or use moral claims inside conditionals: “If murder is wrong, then paying someone to murder is wrong.” But emotivism rejects the idea that moral claims can be true or false, so it is not clear why they should behave in arguments as if they were the kind of sentences that can be true or false. If moral language is only a matter of expressing feelings, why couldn’t someone consistently say “boo murder” and “hurrah for murder intentions,” in the same way that they can dislike vanilla ice cream but like chocolate ice cream?

Another possible answer is to say: yes, moral statements can be true or false, but ordinary positive moral judgements are all false! There is no realm of objective moral facts “out there”, so when we say “murder is wrong” we are systematically mistaken about what exists. This view, famously defended by John Mackie and known as error theory, holds that moral judgements are always in error. From that perspective, much traditional moral debate on moral truths looks a bit like the supposed Byzantine debates on whether angels are male or female: it discusses claims about presupposed entities that do not exist.8

Criticism of error theory. Saying that moral claims are wrong when they assume absolute moral truths is fine. But it doesn’t follow that moral claims can’t be true or false in a more limited way. The sentence “You can’t do that”, frequently uttered when playing board games, can be true or false even though it does not rely on any absolute truths “out there”, only on the existence of commonly agreed rules of play. In fact, Mackie invites us to look at empirical studies of how morality actually works in human societies, and Binmore saw his own work as following in Mackie’s footsteps.

Mackie tells us to look […] for a framework within which to make sense of […] anthropological data, he directs our attention to Von Neumann’s theory of games. — Binmore (2005)

The naturalistic approach I develop here answers yes to the question of whether moral statements can be true or false. However, if they are not true or false in the sense of moral realism, in what sense can they be true or false? The answer is that different social groups can have different moral rules. Within each group, a statement such as “X is wrong” can be true or false given these rules.

If this is the case, it is natural to ask where these rules come from: how are they constructed? One possible answer is radical cultural relativism. This position takes the view that different moral systems happen to be what they are in a given society for historically contingent reasons that might be arbitrary. These moral systems are not comparable across times and places. They are “incommensurable” (there is no measure we could use to compare them). As a result, we are never able to compare moral rules across cultures because we do not have a valid external standpoint from which to do so.9

Criticism of radical cultural relativism. Radical cultural relativism has too many unanswered questions. It does not offer a positive theory of how moral systems emerge and evolve. Why do societies have the moral systems they have? Are they arbitrary? Can they prescribe any kind of action at all? If so, why should we care about them? Why do people follow them?10

The view I develop here does not pursue this route. It posits that moral systems do not simply happen to be what they are for purely historically contingent reasons. They emerged from cultural evolution to serve a function: to help foster and regulate social cooperation. This approach is often referred to as Humean constructivism because philosopher David Hume was perhaps the earliest proponent of this view:

The rules of equity or justice depend entirely on the particular state and condition in which men are placed, and owe their origin to that utility which results to the public from their strict observance. — Hume

Surprisingly, this approach remains a blind spot in mainstream academic metaethics. The view I am developing here builds on important contributions by authors such as Robert Sugden, Brian Skyrms, Cristina Bicchieri, and Ken Binmore, whose work is largely ignored in standard metaethical discussions. A quick look at the main textbooks is revealing. Neither these authors, nor their method of inquiry—game theory—is mentioned in van Roojen’s Metaethics (325 pages), Miller’s Contemporary Metaethics (570 pages), or Chakraborti’s Introduction to Ethics (768 pages).

Binmore noted this somewhat peculiar absence of engagement with game theory in the philosophical literature on morality. When philosophers have to look into the possible insights game theory can bring to our understanding of morality:

It is at this point that scientific philosophers tend to falter. Game theory books are mostly written by economists, who use an exotic vocabulary and complicated mathematical equations. — Binmore (2005)

I strongly agree with Binmore that this is a pity. In a way, it is not warranted, as many important findings from game theory can be explained simply. Indeed, it is the standpoint of this Substack to bring some of its key insights in a faithful but approachable way.

[…] there is nothing arcane about game theory. On the contrary, what has to be explained in this chapter is embarrassingly easy. The exotic vocabulary and the fancy equations of game theory books are just more of the dust that scholars always kick up lest it be found out that what they have to say isn’t very profound. — Binmore (2005)11

As a result of this relative absence in metaethics, many moral philosophers are likely less familiar with the conceptual stance I present and may, on the basis of my previous post against moral realism, have been unsure where to locate it: emotivism? cultural relativism? error theory? This post (and the next) places this perspective in an approach that stands mostly outside the bulk of the discussion in metaethics, and yet is a position that is conceptually solidly grounded in our understanding of human interactions.

Another way to represent what distinguishes this position from most metaethical positions is to map these positions in a diagram distinguishing both realism from anti-realism and game-theoretical/evolutionary foundations from an absence of such foundations. The graph below does this for a non-exhaustive list of thinkers, blending classical philosophers and more modern thinkers.12

A moral theory of the Seemly

Having located this approach in the intellectual space of moral philosophy, it is now time to flesh it out and describe what vision it offers about morality. It is a big challenge to explain it simply, while doing it justice within the space of a Substack post. Here I will describe what it stands for. In the next post, I’ll discuss the implications of this position and compare these implications to other ethical positions.

The Good, the Right and the Seemly

Binmore distinguishes two main ways of thinking of morality as objective “out there”. The first is to assume that some things have an objective value and we ought to act to foster the presence of this value in the world. Such theories are called consequentialist. We can call them theories of the Good. The second is to assume that there are some fundamental moral principles out there that we ought to follow. Such theories are called deontological. We can call them theories of the Right.

A Humean constructivist approach rejects the claim that there are absolute moral truths out there—be they values or principles—that should guide our actions. Instead, it posits that our moral code is a human creation that serves to foster social cooperation.13

Having rejected the theories of the Good and the theories of the Right, Binmore labels his approach a theory of the Seemly, that is, a theory of morality as what is appropriate given social conventions about morality.

I try to capture this down-to-earth attitude to morality by calling it a theory of the seemly. Although theories of the seemly aren’t currently popular among moral philosophers, they have a long and respectable intellectual history. Aristotle, Epicurus, and Hume are perhaps the most famous Western exponents of the approach, but if one could mention only one name it would have to be that of Confucius.14

Within a theory of the seemly, things aren’t good or right in themselves; they are good or right because they are generally held to be good or right in a particular society. — Binmore (2005)

Thinkers like Robert Sugden, Brian Skyrms, Cristina Bicchieri and Ken Binmore develop such a theory of the Seemly by using game theory to explain the content and inner workings of moral systems. In short, this view relies on two key ideas. First, moral rules are equilibria of social games: they regulate stable patterns of social interactions. Second, these rules have emerged and persisted because they help solve recurrent coordination and conflict problems in ways that are, on balance, advantageous for enough members of the society to be stable.15

Moral rules are rules of the Game of Life

From this perspective, if there is an “ought” to follow these rules, it is not an unconditional mysterious ought coming from intangible moral values and principles that apply universally. We ought to respect moral rules because they are the rules of the social games we play. If you start playing Association Football (soccer), you should not grab the ball and run towards the opposite goal. Why? Because “handball is wrong” in football. And if you want to play football, you should respect that rule.

You might still ask, but in what sense ought we to abide by moral rules? Why shouldn’t we be happy instead just doing what we want? Here again, the explanation is no longer mysterious. You ought to abide by moral rules because they are an equilibrium of the social games you play. As a consequence, they are self-enforced by sanctions built into the game for those who do not respect them. It is perfectly meaningful to say something like “If you don’t want to be penalised, you ought to respect the rules”. This is a conditional ought, which is rational for you to follow, given the rules of the game. It is not an unconditional ought based on some assumed external moral truth.

I expect that this deflationary account of moral claims—i.e. an account which reduces the meaning of moral claims—will feel unsatisfactory to many. Isn’t morality radically more important than the rules of a sport? Some may point out that we feel more strongly about statements like “murder is wrong” than about “handball is wrong in football”.

The answer here is that yes, moral rules are much more important to us than sporting rules because moral rules are the rules of the Game of Life, the one that determines our success and setbacks in life, at work, with friends or romantic partners, with family members, and so on. It makes perfect sense for us to have a moral sense that makes us care greatly about how the Game of Life is played. There is no reboot and no respawn in this game, and it determines everything that matters to us.

Our moral sense, shaped by eons of evolution, is designed to provide us with emotions that help us play the Game of Life successfully. Any deviation from the moral code puts us at risk of future sanctions: blame, ostracisation, and even, in some cases, violence. Our moral emotions track the costs of deviations and bring them back into our present. They embed this shadow of the future in our daily experience. Talking about our moral cognition, cognitive scientists André et al. (2022) write:

[…] morality is not a set of rigid and stereotyped principles, but a flexible context-dependent calculator of what one must do to secure a good reputation and attract future cooperative investment from others.

Such an explanation might seem to conflict with the phenomenology of our experience of moral behaviour—i.e. how we experience engaging in making moral judgements. Moral feelings are typically experienced as primary feelings, not the reflections of some practical trade-offs about future payoffs. Isn’t this discussion of “calculations” misguided?16

It is important, here, to stress the two different levels of explanation of behaviour in evolutionary theory: ultimate explanations are about why a type of behaviour was selected by evolution, while proximate explanations are about how such types of behaviour are generated by our cognition. Saying that our moral sense is designed to track the payoffs of respecting or deviating from moral rules is an ultimate explanation. But, in our everyday lives, we typically choose to behave morally because we experience moral emotions, this is the proximate explanation of our behaviour. And our moral feelings can be strong because the stakes of the Game of Life are high.

Humean constructivism, in spite of a coherent conceptual framework grounded in ideas and results from game theory, is marginal in mainstream ethical discussions. The reason might come from the technicality of game theory, but also possibly from the seemingly less appealing view that morality is not grounded in absolute principles but in social conventions.

Aside from intellectual considerations, theories of the Seemly do not have the same social cachet as the grandiose theories of the Good and the Right. But perhaps the fact that people like me are moved to write books like this is a sign that the time for Seemliness has come. — Binmore (1998)

However grandiose the theories of the Right and the Good might be, they will only lead us to err endlessly in conceptual mazes if they are misguided. From that perspective, having the epistemic courage to abandon these absolute views and accept the social nature of morality opens the way for us to attain a greater clarity on what morality is and how it works.

Derek Parfit started his highly influential book Reasons and Persons with a quote from Nietzsche that reflects his view that abandoning religious foundations for morality opens us to a radically new understanding of morality, something real but secular. In the same way, the Humean constructivist perspective on morality opens a radical perspective, different from much that has preceded it in moral and political philosophy, enlightening even if a bit daunting in parts.

At last the horizon appears free to us again, even granted that it is not bright; at last our ships may venture out again, venture out to face any danger; all the daring of the lover of knowledge is permitted again; the sea, our sea, lies open again; perhaps there has never yet been such an “open sea”. — Nietzsche

References

André, J.B., Fitouchi, L., Debove, S. and Baumard, N., 2022. An evolutionary contractualist theory of morality. PsyArXiv. May, 24.

Ayer, A.J. (1936) Language, Truth and Logic. London: Gollancz.

Bicchieri, C. (2006) The Grammar of Society: The Nature and Dynamics of Social Norms. Cambridge: Cambridge University Press.

Binmore, K. (1994) Game Theory and the Social Contract, Volume 1: Playing Fair. Cambridge, MA: MIT Press.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. Cambridge, MA: MIT Press.

Binmore, K. (2005) Natural Justice. Oxford: Oxford University Press.

Binmore, K. (2012) ‘Kitcher on Natural Morality’, Analyse & Kritik, 34(1), pp. 129–140.

Carnap, R. (1963) ‘Intellectual Autobiography’, in Schilpp, P.A. (ed.) The Philosophy of Rudolf Carnap. La Salle, IL: Open Court, pp. 3–84.

Chakraborti, C. (2023) Introduction to Ethics: Concepts, Theories, and Contemporary Issues. Singapore: Springer.

Edmonds, D. (2023) Parfit: A Philosopher and His Mission to Save Morality. Princeton, NJ: Princeton University Press.

Hume, D. (1751) An Enquiry Concerning the Principles of Morals. London: A. Millar.

Mackie, J.L. (1977) Ethics: Inventing Right and Wrong. London: Penguin.

Miller, A. (2003) An Introduction to Contemporary Metaethics. Cambridge: Polity Press.

Nietzsche, F. (1882) The Gay Science. (Various editions; citation here refers to the work from which the closing passage is taken.)

Parfit, D. (1984) Reasons and Persons. Oxford: Clarendon Press.

Parfit, D. (2011) On What Matters. Oxford: Oxford University Press.

Skyrms, B. (1996) Evolution of the Social Contract. Cambridge: Cambridge University Press.

Sugden, R. (1986) The Economics of Rights, Cooperation and Welfare. Oxford: Basil Blackwell.

van Roojen, M. (2015) Metaethics: A Contemporary Introduction. New York: Routledge.

von Neumann, J. and Morgenstern, O. (1944) Theory of Games and Economic Behavior. Princeton, NJ: Princeton University Press.

Westermarck, E. (1906–1908) The Origin and Development of the Moral Ideas. London: Macmillan.

This Substack is not for the epistemically faint-hearted (i.e. not for those afraid of what the truth might be), so let’s get something out of the way. I believe it does not make sense to talk of morality as being objective, in the sense that there would be absolute moral truths.

The reason is that, if you take a naturalistic approach without skyhooks, I do not see in what sense there could be moral truths external to us. Where would they come from? How would we access them? I share the incredulity Binmore expresses here:

Diogenes remarked that he had seen Plato’s cups and table, but had yet to see his cupness and tableness. I feel much the same about the Platonism of traditional theories of the Good and the Right. — Binmore (1998)1

The philosopher most well-known for rejecting the absolute reality of morality is Nietzsche. In Beyond Good and Evil, he stated:

There are no moral phenomena, only a moral interpretation of phenomena.

For him, moral statements do not reflect some objective moral truths. They are social and historical narratives, human inventions. But wait, isn’t this paving the way to moral relativism, and the justification of any horrible behaviour we can think of? Here, I discuss why there is no reason to believe that there are absolute moral truths. In the next post, I’ll discuss why this conclusion does not lead to the justification of asocial behaviour.

Preferences over ice cream and Nazis

One specific aspect of morality is that we tend to experience moral norms as objective and externally imposed, rather than as mere personal preferences. Philosopher Kyle Stanford illustrates this with the contrast between saying “I like chocolate ice cream” and “The Nazis were bad.” The first is clearly a matter of taste, but the second feels different, something we take to be true regardless of anyone’s opinions.

Humans experience the demands of morality as somehow imposed on us externally: we do not simply enjoy or prefer to act in ways that satisfy the demands of morality; we see ourselves as obligated to do so regardless of our subjective preferences and desires, and we regard such demands as imposing unconditional obligations not only on ourselves, but also on any and all agents whatsoever, regardless of their preferences and desires. — Stanford (2018)2

The notion that moral injunctions have some objective nature is associated with moral realism, the idea that moral rules are real laws, in the same sense as the laws of physics.3

The philosophers’ view

Modern philosophy has become mostly secular, but it is striking that the majority of philosophers seem to continue to support the view that there are absolute truths, independently of the question of the existence of a God. A recent 2020 PhilPapers Survey indicated a clear majority supporting moral realism among philosophers across the world.

On Substack, philosophers like Peter Singer, , , , , , are in favour of moral realism while , , and are opposed to it.

The argument for moral realism

Moral realists argue that we can build a theory of morality. There are many different justifications for moral realism, but they often share similar features, such as the observations that we have strong moral feelings and experience them as objective, which might vindicate looking for the objective reasons behind these feelings.

To engage seriously with moral realism, I’ll focus on the arguments of two influential thinkers: Derek Parfit, a leading moral philosopher, and Sam Harris, a well-known public intellectual with a wide popular impact.4

Derek Parfit’s non-naturalist moral realism

Derek Parfit is commonly seen as one of the most important moral philosophers of recent times, if not the most important. His views have had a major influence in academic circles and beyond. It therefore makes sense to turn to him when looking for one of the best possible advocates of moral realism. He defends the objectivity of morality in his book On What Matters (2011).

At the heart of Parfit’s view is the claim that, in addition to “internal” reasons we have for action (those that come from our personal desires), there are objective “external” reasons to act that apply to us whether or not we are motivated by them. Imagine a person who enjoys causing pain and feels no sympathy or guilt. Given his present desires, he would be happier if he tortured a defenceless prisoner. On a purely “internal reasons” view, this person has no reason not to torture; in fact, he has an internal reason to torture, because it satisfies his strongest desires. Parfit wants to say that, even if this person has no such internal motives, he still has a powerful reason not to torture. That reason does not depend on what he now wants; it is grounded in the suffering he would inflict. This is what Parfit means by an external reason, and he argues that such external reasons are real.

We all have reasons to regret anyone’s suffering, and to prevent or relieve this person’s suffering if we can, whoever this person may be, and whatever this person’s relation to us. We have such reasons to prevent or to regret the suffering of any sentient or conscious being. — Parfit (2011)

If there are external reasons, can we systematise them and build a moral theory that makes sense of them? Parfit thinks so, and he claims that, in the process, this theory unifies the main moral approaches, Kantianism, rule consequentialism, and contractualism, which, on his view, have been climbing the same mountain from different sides.5

This systematisation relies on making sure we uncover a moral theory that is internally coherent: it does not lead to contradictory injunctions. It also relies on checking that its conclusions align with our reasoned moral intuitions (those moral intuitions that withstand some scrutiny) about what the right thing to do is.

We might question what the epistemic status of such a systematisation is. Let us say Parfit is successful at building such a theory. What does that mean?

From a naturalistic point of view, there are basically two ways in which a theory can earn its keep. First, it should be logically coherent. Second, it should be answerable to experience in some way. Hume makes this point bluntly:

If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion. — Hume

Parfit claims that his reasoning does not fit within this dichotomy, that it is possible to find irreducibly normative truths by rational reflection. In fact, I think he is in practice only doing a variation on it. To start with, he clearly aims to produce a consistent theory. That is central to his project. Then, how does he “test” whether this theory is acceptable? He says that he reasons with cases and principles. But in practice, on what grounds does a case lead him to accept or reject a conclusion? It is whether the injunction to act in a certain way in that case fits with our considered moral intuitions.6

In other words, Parfit uses moral intuitions as the raw material against which principles are tested, using clever thought experiments that set up unusual situations as stress tests for the general application of those principles. From a naturalist point of view, what he actually does is to organise our moral intuitions into a coherent system, rather than to open an independent window onto a further layer of moral reality.

A problem with this approach is that it gives a lot of weight to our moral intuitions as the primary substrate on which to build a theory. The fact that we have intuitions is obvious, but why should we treat our intuitions as pointing to some moral truth “out there” to be discovered?7

One reason given by Michael Huemer, who also defends moral realism, is that

It is reasonable to assume that things are as they appear, in the absence of grounds for doubting this. — Huemer8

Applied to morality, the idea is: moral truths appear to us to be objective, and unless we have strong reasons to distrust this appearance, we should take it at face value. Our intuitions about right and wrong are then treated as evidence for objective moral facts.

With all due respect to Huemer, this is a weak argument once we take seriously what we know about how our moral psychology evolved. We have very good independent explanations of why we have moral intuitions, without positing a realm of moral truths “out there”. Our moral sense appears to be an evolved tool for navigating social life: coordinating cooperation, managing conflicts of interest, punishing betrayal, and so on. Seen in that light, there is no particular reason to expect our intuitions to track some separate, non-natural moral reality. We should expect them instead to track what tends to work well for creatures like us in the kinds of social games we actually play.

Put differently: even if you can build a neat and coherent theory that organises these intuitions, that does not by itself show that the theory describes objective moral facts. It may simply be a good higher-level description of the strategies that help us do well in social interaction. If our shared moral intuitions are there to guide us towards sensible behaviour in repeated social interactions, they will need to be broadly compatible with equilibrium strategies of social games: strategies that it is in our interest to follow when others follow them too.

For instance, to the extent that it is good to cooperate with people who are willing to cooperate with us, and not to cooperate with people who just want to take advantage of us, we should have clear moral intuitions about reciprocity.

In pure epistemic terms, it is not clear why the enterprise Parfit undertakes would lead to objective moral truths that are “mind-independent”, as described by moral realists. This criticism was advanced precisely by philosopher Sharon Street:

The challenge for realist theories of value is to explain the relation between these evolutionary influences on our evaluative attitudes, on the one hand, and the independent evaluative truths that realism posits, on the other. Realism, I argue, can give no satisfactory account of this relation. — Street (2006)

Even if there were objective moral truths “out there”, there would be no reason to expect our moral intuitions to be special windows onto them, since these intuitions are shaped by evolution, which is a blind process with no reason to drive our cognition towards intangible moral truths. Instead, it shapes our cognition to help us be successful in the sense of surviving and having surviving offspring.9

Sam Harris’ naturalist moral realism

Sam Harris is a neuroscientist and public intellectual, with several New York Times best-selling books. He hosts the podcast Making Sense, which has a large international audience. Harris developed his perspective on morality in his book The Moral Landscape (2010).

I chose to discuss Harris’ views because many readers are likely familiar with them, and also because his starting point is naturalistic, like the one I adopt in this Substack. Harris wants to ground morality in facts about conscious creatures and their experiences, not in a religious or metaphysical realm. This makes it easier to engage with his ideas and to identify where disagreements lie.

Harris’ starting point is that we are evolved beings with nervous systems that generate conscious experiences of pain and pleasure. From this, he says that some types of experiences are better than others.

He asks us to imagine the “worst possible misery for everyone”: a world in which every conscious being suffers as much as possible, for as long as possible, with no compensating benefits. Opposed to that, we can imagine much better possible worlds. Harris then asks whether we are prepared not to call the first world “bad” and the others “better”. If we are, we have already accepted that there are objective moral facts: some states of the world really are better than others, because they contain more well-being.

There is an obvious question though: as much as we feel that the first world is awful, why should we call it bad in an absolutely-objectively-true way, rather than in a we-really-don’t-like-it way? Harris anticipates this question:

But you haven’t said why the well-being of conscious beings ought to matter to us. If someone wants to torture all conscious beings to the point of madness, what is to say that he isn’t just as ‘moral’ as you are?

His answer has two parts. First, he claims that consciousness is “the only intelligible domain of value”:

I think we can know, through reason alone, that consciousness is the only intelligible domain of value. What is the alternative? I invite you to try to think of a source of value that has absolutely nothing to do with the (actual or potential) experience of conscious beings.

Frankly, I do not follow. With his question “what is the alternative?”, he simply introduces the assumption that there must be some “value” in the world. This is a skyhook. If you assume there needs to be such an objective value, you have pretty much provided a justification for a normative theory out of thin air.10 But what tells us that such an objective value exists? Isn’t that the first question to answer?11

Also, Harris says that “through reason alone” we can know that consciousness is the only domain of value. But, actually, he does not show this using reason. He is really only saying: “come on, you know deep down it is true”.

So really, it is a call to our intuition, and Harris joins Parfit (and many other moral realists) using our intuitions as a primary source of evidence. Having argued for such a value, it is then easy to claim that there are objective rights and wrongs.

Once we admit that the extremes of absolute misery and absolute flourishing—whatever these states amount to for each particular being in the end—are different and dependent on facts about the universe, then we have admitted that there are right and wrong answers to questions of morality.

Why should we agree with his line of argument? Because it is obvious, and, if we don’t, Harris suggests we are a kind of psychopath:

Anyone who doesn’t see that the Good Life is preferable to the Bad Life is unlikely to have anything to contribute to a discussion about human well-being. Must we really argue that beneficence, trust, creativity, etc., enjoyed in the context of a prosperous civil society are better than the horrors of civil war endured in a steaming jungle filled with aggressive insects carrying dangerous pathogens? I don’t think so. (emphasis mine)

The key here is what sense is given to better. Obviously, pretty much everybody would prefer to live in a prosperous civil society rather than in a civil-war-ridden society. But that does not mean that there is an objective value out there saying so. Indeed, the whole exercise should be to prove it, not say it is self-evident.12 Saying so is relying on our intuitions shaped by evolution.

So, Harris is a naturalist who smuggles an ought out of thin air on the ground that it is obvious if we think about it. The problem is that an immaterial ought is anything but obvious. Starting from a naturalist point of view has the merit of grounding the theory in well-known facts about human psychology, but it also makes the leap of faith to a normative standpoint easier to spot in its arbitrariness.

The motivation: appeal to consequences

Reflecting on his achievement, Parfit stated:

My life is my work. I believe I have found some good reasons for believing that values aren’t just subjective and that some things really do matter. If my arguments don’t succeed, my life has been wasted. — Edmonds (2021)

This existential motivation should, if anything, make us doubt Parfit’s intellectual impartiality. In a previous post, I described how the desire to believe something is true because we prefer it to be true, what I call the Santa Claus fallacy, often underlies technical arguments about morality.13

When looking at the motivations of moral realists, they often openly express a strong preference for the existence of moral truths, to the point of fitting the Santa Claus fallacy.14

Consider, for instance, David Enoch in Taking Morality Seriously:

In particular, under non-objectivist metaethical assumptions […] it would be morally impermissible to stand one’s moral ground in any number of conflicts or disagreements where it does seem permissible (perhaps even required) to stand one’s moral ground.15

In other words: if we want to be able to say that something is morally wrong, we need to believe there are objective moral truths.

Another moral realist, Russ Shafer-Landau, writes in Moral Realism: A Defence:

[if modesty, liberality, and tolerance were human constructs], then the illiberal and the intolerant, who have constructed things differently, would be making no error. — Shafer-Landau

In other words: if we want to be able to say that the illiberal and intolerant are morally wrong, we need to believe there are objective moral truths.

Huemer says in Ethical Intuitionism:

Lastly, moral anti-realism undermines our sense of meaning in life, and this brings me to one of the reasons why I find anti-realism unbelievable. I think anti-realism really boils down to the view that nothing matters. […] Life has no meaning, because “meaning” is one of those ‘spooky’, non-natural properties that anti-realists do not believe in.16 — Huemer

In other words: if we want our lives to have meaning, we need to believe that there are objective moral truths.

Turning back to the two thinkers I discussed earlier, Parfit wrote in On What Matters:

On subjective theories, nothing matters. We should reject the arguments for this bleak view.

And Harris wrote in The Moral Landscape:

Few people seem to recognize the dangers posed by thinking that there are no true answers to moral questions.

These appeals to consequences are flawed arguments. Whether I prefer something to be true or not should not influence my belief in it being true. I might have a very strong preference for Santa Claus to be real; it won't make it in the least more real. Similarly, the fact that I would very much like moral rules to be objective because of the judgements they would allow me to make is irrelevant to assessing whether these rules exist objectively.17 That such brilliant minds resort to such a flawed type of argument is testimony to the fact that our reason is a tool selected for us to convince ourselves and others, not primarily to find the truth.

In the end, the search for a justification for an objective theory of moral truth might be seen as an attempt to retain, within a secular framework, the type of absolute moral mindset that Judeo-Christian traditions had until now provided. This criticism was explicitly made by Sartre

Towards 1880, when the French professors endeavoured to formulate a secular morality, they said something like this: God is a useless and costly hypothesis, so we will do without it. However, if we are to have morality, a society and a law-abiding world, it is essential that certain values should be taken seriously; they must have an a priori existence ascribed to them. It must be considered obligatory a priori to be honest, not to lie, not to beat one’s wife, to bring up children and so forth; so we are going to do a little work on this subject, which will enable us to show that these values exist all the same, inscribed in an intelligible heaven although, of course, there is no God. […] nothing will be changed if God does not exist; we shall rediscover the same norms of honesty, progress and humanity, and we shall have disposed of God as an out-of-date hypothesis which will die away quietly of itself. — Sartre (1946)

William James suggested that philosophers often fall into two temperamental camps: the tender-minded, who are drawn to idealistic, and often more comforting, views, and the tough-minded, who insist on sticking to experience, facts, and logic, even when the resulting conclusions are not especially appealing.

This Substack definitely stands on the tough-minded side. There is no point in trying to argue that Santa exists just because we would like it to be the case. If we agree there is a reality out there, it does not depend on what we would like it to be. Understanding it as it is requires us to follow where logic and facts guide us. Furthermore, given the design of human reason—filled with reasoning biases that conveniently land us on our preferred conclusions—we should lean towards being suspicious of, rather than drawn to, our own preferences. In the domain of morality, this means that while we may find the idea of absolute moral truths appealing, we should be particularly vigilant about the reasons we accept in support of this view. The view I present in this post is that, when we do so, there are no good reasons to believe that it makes sense to talk of an objective moral reality out there.18

This conclusion leads to a natural question. Does the rejection of moral realism imply a radical relativism that takes the form of subjectivism (moral judgements are nothing more than personal preferences)? Does it mean that anything goes and that we have to agree that things like torture, slavery, and genocide are fine?

The answer here is negative. If morality is understood as being about social rules of cooperation, moral judgments are not just meaningless drivel. In that sense, the naturalistic perspective I develop here is different from the conclusions Nietzsche draws about morality. Discussing this, Binmore states:

[…] the classic error that Nietzsche makes on behalf of all the other thinkers who contrive to muddle the distinction between relativism and subjectivism is to confuse moral values and personal tastes. Morality evolved to regulate interactive human behavior. All the members of a particular society need to be playing the same morality game for its rules to serve any purpose. What would be the point of morality if it differed not only from one society to another, but also from one individual to another? — Binmore (1998, emphasis in the original)

A natural question is: what exactly is morality in this naturalist perspective? This will be the topic of my next post.

References

Binmore, KG (1998) Game Theory and the Social Contract, Volume 2: Just Playing. MIT Press, Cambridge, MA.

Bourget, D & Chalmers, DJ (2023) ‘Philosophers on Philosophy: The 2020 PhilPapers Survey’, Philosophers’ Imprint, 23(11).

Edmonds, D (2023) Parfit: A Philosopher and His Mission to Save Morality. Princeton University Press, Princeton, NJ.

Enoch, D (2011) Taking Morality Seriously: A Defence of Robust Realism. Oxford University Press, Oxford.

Golub, C (2021) ‘Is there a Good Moral Argument against Moral Realism?’, Ethical Theory and Moral Practice, 24(1), pp. 151–164.

Harris, S (2010) The Moral Landscape: How Science Can Determine Human Values. Free Press, New York.

Huemer, M (2005) Ethical Intuitionism. Palgrave Macmillan, Basingstoke.

Hume, D (1748) Philosophical Essays Concerning Human Understanding. A. Millar, London.

Hume, D (1755) ‘Of Suicide’, in EF Miller (ed.) Essays: Moral, Political, and Literary. Liberty Fund, Indianapolis.

James, W (1907) Pragmatism: A New Name for Some Old Ways of Thinking. Longmans, Green & Co., New York.

Mackie, J.L. (1977) Ethics: Inventing Right and Wrong. Harmondsworth: Penguin Books.

Nietzsche, F (1886) Beyond Good and Evil: Prelude to a Philosophy of the Future. C. G. Naumann, Leipzig.

Parfit, D (2011) On What Matters. 2 vols. Oxford University Press, Oxford.

Pölzler, T & Wright, JC (2019) ‘Empirical research on folk moral objectivism’, Philosophy Compass, 14(5), e12589.

Sartre, J-P (1946) L’existentialisme est un humanisme. Les Éditions Nagel, Paris.

Shafer-Landau, R (2003) Moral Realism: A Defence. Clarendon Press, Oxford.

Stanford, PK (2018) ‘The difference between ice cream and Nazis: Moral externalization and the evolution of human cooperation’, Behavioral and Brain Sciences, 41, e95.

Street, S (2006) ‘A Darwinian Dilemma for Realist Theories of Value’, Philosophical Studies, 127(1), pp. 109–166.

13

One of the commenters to my post made exactly this point

Religion is one of the most natural justifications for the existence of objective moral truths. Sacred texts handed out to us by a superior divine being provide a seemingly natural origin to morality.

This idea is so prevalent that the absence of belief in God is associated with an anxiety about the absence of morality. Sartre, an atheist, pointed out this concern:

[It is] extremely embarrassing that God does not exist, for there disappears with Him all possibility of finding values in an intelligible heaven. There can no longer be any good a priori, since there is no infinite and perfect consciousness to think it. It is nowhere written that ‘the good’ exists, that one must be honest or must not lie, since we are now upon the plane where there are only men. — Sartre

This belief that God is necessary to hold together our desire for morality to mean something is often used to justify explicitly or implicitly the existence of God, in what I call a Santa Claus fallacy—”Santa must exist because it would be too horrible if he didn’t”.

Here I explain why the idea that morality requires religion gets things backward, not only does religion not clearly underpin our moral sense, it is most likely our moral sense which has shaped religions.

The Euthyphro dilemma

Sartre’s quote reflects a widely shared belief that it is the existence of God which justifies the existence of moral truths. But is it really the case?

A problem with this idea was pointed out more than 2,000 years ago by Plato. In his dialogue Euthyphro, he presents a dilemma about morality and God. Is something moral because God said it is? Or does God give us injunctions to do something because it is moral?

If we accept the idea that something is moral because God said so, it makes morality arbitrary in the sense that we would have to accept as moral whatever God told us was moral. What if God told us that stealing or killing our neighbour is moral? To many, it would seem wrong for God to say that.

If, on the contrary, we say that God gives us injunctions because they are moral, then morality must be defined outside of God. In that case, we have not solved the question of the origin of morality.1

When religion conflicts with our moral intuitions

Evidence from psychology seems to suggest that believers behave as if they assume morality exists outside of God. This is illustrated by how they react to scenarios where God would recommend that we do things we unambiguously consider bad. Studying morality in children, psychologist Larry Nucci found that:

[…] the majority of children at all ages and from both religious groups rejected the notion that God’s command would make it right for a person to steal. […] Instead, children attempt to coordinate their notions of God with what they know to be morally right. — Nucci (1991)

He cites this interview with a conservative Jewish boy as an illustration:

Question. Let’s suppose that God had written in the Torah that Jews should steal, would it then be right for Jews to steal?

Answer. No.

Question. Why not?

Answer. Even if God says it, we know he can’t mean it, because we know it is a very bad thing to steal. We know he can’t mean it. Maybe it’s a test, but we just know he can’t mean it.

Question. Why wouldn’t God mean it?

Answer. Because we think of God as very good—absolutely perfect person.

Question. And because He’s perfect, He wouldn’t say to steal? Why not?

Answer. Well—because we people are not perfect, but we still understand. We are not dumb either. We still understand that stealing is a bad thing.2

A recent psychological study found that when asked whether it would be right for God to support a range of behaviour we typically reject, most children stuck to their moral norms instead of accepting the idea that they should simply follow a divine injunction.

Children of varying religious backgrounds identified moral norms… as authority-independent… even if God had made a commandment requiring people to steal, stealing would still be immoral. — Reinecke and Solomon (2023)

Another element in support of the primacy of our moral intuitions is that critics of religion often point to elements in them that conflict with our modern moral sense—like the justification of mass killings or of the inferior status of women.3 What would be the point of these criticisms if believers were just willing to accept that whatever God prescribes is the right thing to do? If critics resort to such criticisms, it is because they believe it will appeal to a moral sense that exists outside of religion and can be used to convince believers to disagree with religious teaching.

The cultural evolution of religions and how our moral sense shaped it

There are indeed good reasons to think that our morality precedes religion: our moral sense is a tool to help us navigate social interactions and cooperate successfully with others without being pushovers. Nicolas Baumard developed precisely this view in his book The Origins of Fairness:

Our moral disposition is specialized, autonomous, universal, and innate because it was selected by evolution. — Baumard (2010)

It is then not religion that gave us our moral intuitions, but our moral intuitions that helped shape religions. In support of this view, one can first observe that religions are incredibly diverse and that many forms of religion observed across times and places differ radically from the large monotheist religions we are accustomed to.

The anthropologist Stewart Guthrie discusses this diversity in his book Faces in the Clouds. This kind of comparison is useful to rule out some simple explanations of why religion arose in the first place.

Religion does not simply emerge to offer us a belief in an afterlife, because many religions do not place much weight on a consoling afterlife, and, in others, the afterlife is barely articulated or quite bleak.

Religion cannot have simply emerged to make sense of the world in some grand or ultimate way, because many religions are largely this-worldly and pragmatic, concerned with local misfortunes rather than with providing a comprehensive cosmology.

Religion cannot be simply about making us moral either, because many religions do not prescribe systematic moral behaviour, and some famous gods (such as the Greek gods) show little intrinsic interest in morality.

What Guthrie suggests is that religions arise, at least in part, from our evolved propensity to over-detect agency in the environment: we quite literally tend to see faces in the clouds. From an evolutionary point of view, this bias is useful because the cost of a false positive (thinking there is an agent when there is none) is usually small, while the cost of a false negative (failing to notice a predator, rival or ally) can be fatal. In ambiguous situations, it is therefore adaptive to be overly susceptible to assuming that some agent might be present. That is why we find creaking noises in old houses creepy and why we might jolt at the sound of leaves rustling in the bushes.

Guthrie’s claim is that religious concepts build on this general tendency: once the mind is primed to interpret ambiguous patterns as agents, it is a short step to populating the world with invisible persons, spirits and gods.

The anthropologist Pascal Boyer builds on Guthrie’s idea and argues that this propensity to over-detect agency helps explain the appeal of spirits and gods as minimally counterintuitive agents: agents that respect most of our intuitions about behaviour and even physics, with a few notable exceptions such as being invisible or able to perform miracles. Boyer suggests that religious traditions naturally blend such agents with our moral and social intuitions, so that gods and spirits have desires, likes and dislikes, form bonds with us, and take revenge if we break these bonds.

As such stories evolve, some themes are likely to act as cultural attractors4 because of how they resonate with our existing intuitions and preferences. This seems to be the case for moralising gods,5 who justify and enforce our moral sense. Moralising gods might be particularly appealing psychologically because they provide a justification for our feelings that good deeds should be rewarded and bad deeds punished. They satisfy our desire for a just world where no crime goes unpunished. Baumard and Boyer have argued that it is precisely this intuitive appeal that made such religious narratives historically successful.

Despite their differences, religious and non-religious movements owe their cultural success to the fact that these explicit, coherent accounts of moral prescriptions are congruent with universal, and much older, evolved moral intuitions. — Baumard and Boyer (2013)

In addition, moralising gods can help make societies more cohesive and cooperative, and therefore more successful. By creating beliefs that justify cooperative behaviour and increase the perceived costs of anti-social behaviour, moralising gods might help societies sustain a higher degree of social trust and a higher level of cooperation.6 In his sociology of religion, Max Weber has emphasised that one of the reasons for the economic success of Protestants was the effect of an ever-judging God (with the absence of the regular process of forgiveness of confession present in Catholicism):

[The puritan Protestant was characterised by] trust, especially his economic trust in the absolutely unshakable and religiously determined righteousness of his brother in faith. — Weber 1915

The game-theoretic foundations of our morality

So instead of religions being the foundation of our morality, it is our moral sense that likely led large world religions to evolve progressively into their moralising form. In support of this view, we have very good ideas about why our moral sense has precisely the features it has.

One of the most striking findings of the research in game theory in the second part of the 20th century was that it is rational to cooperate in repeated interactions7 and that very simple strategies like tit-for-tat (being kind to people who have been kind to you and not being kind to those who have not).8 The reason is simple. When people interact over time, being uncooperative now risks losing the gains from cooperation later. In his book The Evolution of Cooperation, Robert Axelrod stressed how the shadow of the future can make honesty and cooperation the best policy.

These findings left, however, one issue unresolved: there are many ways to cooperate and each way is associated with different splits from the gains of cooperation. Alice and Bob might be happy to form a family, but to have a happy and functional family they need to split the house chores, the childcare duties, the income-generating activities, and so on. There are many ways to split these things, and 50-50 everywhere is not necessarily a feasible or preferred solution. To start with, Alice cannot share the long and difficult process of making children with her partner, and she might expect him to pull his weight in other domains.

A key insight from game theorist Ken Binmore is that agreeing on how to organise cooperation, and split the gains it generates, involves some bargaining. He developed a theory where a key cognitive tool to solve this problem is for us to put ourselves in the shoes of other people, to take their side to be able to propose solutions that would be agreeable to all.

This cognitive tool is nothing else than the Golden Rule: “Do unto others as you would have them do unto you.”9 A striking aspect of this rule is how it can be found in pretty much the same form across widely different cultures and religions.10

It can also be found in secular ethical philosophy. Kant’s categorical imperative can be understood as a sophisticated elaboration of the Golden Rule:

Act only in accordance with that maxim through which you can at the same time will that it become a universal law. — Kant (1785)11

And John Rawls presents the original position with its veil of ignorance as a procedural way of applying Kant’s categorical imperative to the choice of social rules.

The original position may be viewed, then, as a procedural interpretation of Kant’s conception of autonomy and the categorical imperative within the framework of an empirical theory. — Rawls (1971)

Binmore thinks that such philosophies have been attractive because the Golden Rule, which he sees as a “simplified version of the original position,”12 is a fundamental principle of our psychology to navigate social interactions and negotiate with others. In short, we put ourselves in other people’s shoes to find a solution that works for all.13

For me, the original position is merely a stylized representation of a fairness norm that evolved along with the human race for the purpose of resolving small-scale coordination problems. — Binmore (1998)

In that perspective, it is not just reciprocity that is one of the foundations of our psychology; it is also about how we organise this reciprocity to coordinate on mutually agreed solutions. These deep intuitions exist universally because they are solutions to problems of cooperation faced for eons by our ancestors. Our moral sense is based on these deep intuitions. They do not derive from religion; instead, they shaped world religions.

In his article on Morality and religion in the Encyclopedia of Religion, Ronald Green observed the uncanny commonalities of religions’ moral principles in spite of their large diversity in traditions and beliefs.

One of the most striking impressions produced by comparative study of religious ethics is the similarity in basic moral codes and teachings. […] It is sometimes assumed, because religious traditions hold widely different religious beliefs, that their ethics must correspondingly differ; what is remarkable, however, is that these great differences in beliefs apparently do not affect adherence to at least the fundamental moral rules. — Green (1987)

This striking commonality makes sense once we understand that it reflects deep moral intuitions that precede the existence of large world religions, because they are part of the cognitive tools evolution has handed us to be successful as part of a highly social species.

It is common to hear the concern that without religion, morality is impossible. This perspective gets things backward. It is not religions that induce moral motives in humans. Instead, our moral motives pre-existed religions and world religions built on these and gave them a supernatural justification.

References

Atkinson, Q.D. and Bourrat, P. (2011) ‘Beliefs about God, the afterlife and morality support the role of supernatural policing in human cooperation’, Evolution and Human Behavior, 32(1), pp. 41–49.

Axelrod, R. (1984) The Evolution of Cooperation. New York: Basic Books.

Baumard, N. (2010) Comment nous sommes devenus moraux: Une histoire naturelle du bien et du mal [English translation: The Origins of Fairness]. Paris: Odile Jacob.

Baumard, N. and Boyer, P. (2013) ‘Explaining moral religions’, Trends in Cognitive Sciences, 17(6), pp. 272–280.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. Cambridge, MA: MIT Press.

Binmore, K. (2005) Natural Justice. Oxford: Oxford University Press.

Boyer, P. (2001) Religion Explained: The Evolutionary Origins of Religious Thought. New York: Basic Books.

Darwin, C. (1871) The Descent of Man, and Selection in Relation to Sex. London: John Murray.

Dawkins, R. (2006) The God Delusion. London: Bantam Press.

Green, R.M. (1987) ‘Morality and religion’, in Eliade, M. (ed.) Encyclopedia of Religion, Vol. 10. New York: Macmillan, pp. 92–106.

Guthrie, S. (1993) Faces in the Clouds: A New Theory of Religion. New York: Oxford University Press.

Kant, I. (1785) Groundwork of the Metaphysics of Morals. Riga: Johann Friedrich Hartknoch.

Norenzayan, A. (2013) Big Gods: How Religion Transformed Cooperation and Conflict. Princeton, NJ: Princeton University Press.

Nucci, L.P. (1991) ‘Doing justice to morality in contemporary values education’, in Benninga, J.S. (ed.) Moral, Character, and Civic Education in the Elementary School. New York: Teachers College Press, pp. 21–39.

Plato (c. 399 BCE) Euthyphro. In: Cooper, J.M. (ed.) (1997) Plato: Complete Works. Indianapolis, IN: Hackett Publishing.

Rawls, J. (1971) A Theory of Justice. Cambridge, MA: Harvard University Press.

Reinecke, M.G. and Solomon, L.H. (2023) ‘Children deny that God could change morality’, Cognitive Development, 68, Article 101393.

Roes, F.L. and Raymond, M. (2003) ‘Belief in moralizing gods’, Evolution and Human Behavior, 24(2), pp. 126–135.

Russell, B. (1927) Why I Am Not a Christian. London: Watts & Co.

Sartre, J.-P. (1946) L’existentialisme est un humanisme. Paris: Éditions Nagel.

Sperber, D. (1996) Explaining Culture: A Naturalistic Approach. Oxford: Blackwell.

Trivers, R.L. (1971) ‘The evolution of reciprocal altruism’, The Quarterly Review of Biology, 46(1), pp. 35–57.

Weber, M. (1904–1905) ‘Die protestantische Ethik und der Geist des Kapitalismus’, Archiv für Sozialwissenschaft und Sozialpolitik, 20–21.

Soon after they learn to talk, children seem to grasp one somewhat abstract notion: fairness. They are quick to decry the unfairness of many situations: how food is shared at the dinner table, how their parents’ attention is divided among siblings, or how their teacher treats them compared with other pupils. This early disposition to identify what is morally wrong1 and what should be done to make it right further develops as they grow up. In the adult world, normative statements are commonplace. Turn on the TV, and an intellectual will tell you that society should be like this or like that; a politician will say that it is not right for the government to act that way; and an activist will state that social justice requires a change in policy to improve society.

But wait a minute, what do all these statements mean? What does it mean to say we ought to do that, or that it is right to do this? Asking these questions might surprisingly reveal that we typically don’t have very good answers! And, even more surprisingly, experienced thinkers’ answers often rely on intellectual tricks, skyhooks, whose weakness is overlooked only because they deliver the kind of answer our intuitions find comforting.

In this post, and upcoming ones, I argue that we can build a theory of morality without such tricks, a theory consistent with our understanding of natural and behavioural sciences. This theory provides strikingly simple answers to the deep questions that have been asked in philosophy about morality.

Morality put to the toddler’s acid test

Because moral statements are so commonplace, it is easy to fail to appreciate how shallow our thinking about their meaning is. To see this, let’s put them to what I’d call the toddler’s acid test. Toddlers don’t know much, but they are often able to unsettle our confidence in our own “knowledge” with a simple trick: asking questions like “why?”, not just once, but repeatedly, until it becomes evident that we do not actually have all the answers.

Take a simple interaction from the 1990 children's picture book Why? In that book, a little girl, Lily, keeps asking “why?” to her father. Such an unrelenting line of inquiry quickly unveils the dangerously thin layer of knowledge on which adults’ daily confidence is actually based. Consider this possible exchange:

—Don’t sit down there on the grass, Lily.

—Why?

—Because it is not good to have stains on your dress.

—Why is it not good?

—Because you would not look respectable when our friends arrive.

—Why should I look respectable?

[Most dads who are not experts in the philosophy of social norms would start struggling here]

Adults typically end such discussions with “because that’s the way it is”, which is asking for faith in a pragmatic solution that works instead of providing a deep understanding.2

Now imagine a situation where the toddler asks a question about fairness. Let's say she observes on the news that a policy is implemented to increase the income of a category of the population. She inquires

—Why this policy?

—Because they face some hardship and the government is helping them.

—Why is the government helping them?

—Because it is good to help people who have difficulties.

—Why is it good to help people with difficulties?

In truth, most of us would struggle to articulate a meaningful answer to such a disarming toddler. In fact, many professional philosophers would too.3

The physicist Richard Feynman made a very interesting observation about “why?” questions: they are potentially endless.

When you explain a “why,” you have to be inside some framework that allows something to be taken as true. Otherwise, you’re perpetually asking “why.” — Feynman in an interview

One way to end the cycle of “why” questions about morality is to reach a solid and clear foundation. In the same way as mathematics can be grounded in initial statements, axioms, that are accepted as self-evidently true, one hope is that we can do the same about morality. Unfortunately, finding such principles, if ever they exist, has not proven easy.4 De facto, instead of relying on such foundations, theories of morality are often held by skyhooks.

Skyhooks

Skyhooks are explanations that hold our thesis in the air without any further grounding.5 The clearest example of skyhooks is the assumption that morality comes literally from the sky: its rules are handed to us by divine beings.

Examples of divine codes of morality are the Law Code given by the Sun-god Shamash to King Hammurabi, or the Ten Commandments given to Moses on Mount Sinai. Such stories seemingly solve the problem of the foundations of morality. You just have to look at the sacred book of your religion to find out the rules of morality.

A secular alternative is the idea that there are moral truths independently of religious beliefs. It is a widely held intuition that morality is somehow objective, as if there were absolute laws of morality, woven into the fabric of the universe, and which only need to be unveiled. The philosopher Grotius proposed a formal version of this intuition. He argued that humans have natural rights that emerge from natural laws that exist out there, so to speak.6 It is as if there were an invisible book of morality out there in the sky, only requiring us to find ways to recover its content.

Skyhooks have a big flaw: they are not grounded in anything. They therefore require a logical leap, a leap of faith. Why would we make such a leap? Often, the explanation is: because we want to.

The Santa Claus fallacy

On issues of morality, one often hears as an argument something like: “it would be horrible if it were the case”. Versions of this argument take the form: “do you realise the implications of what you are saying?” or “This point of view is so cold-hearted” (i.e. you should not hold this view).

This argument is often made to justify the idea of God. A world without such a being would just be too horrible to think of. As written by Dostoevsky in The Brothers Karamazov: without God, everything is permitted. This argument is also used to back the existence of objective moral laws: “Why should there be objective moral truth? Well, imagine if moral truths did not exist, that would be horrible.”

This type of argument is called an appeal to consequences.7 I call it the Santa Claus fallacy because you can illustrate its absurdity with the case of Santa. Consider seven-year-old Alice, who starts wondering about the existence of Santa. Suppose that another kid points her to some piece of negative evidence, like the fact that Santa has too many kids to visit in one night. Weighing pro and con evidence, Alice decides to reject this counterargument, because it would be too sad if Santa did not exist. Clearly, that would be a reasoning error. Her preferences about the two states of the world—“Santa exists” and “Santa does not exist”—are irrelevant in determining which one is true. Given the fallacious nature of this line of argument, it is surprising how often adults are found using it.

Indeed, even expert philosophers juggling with abstract conceptual arguments are humans, all too human, and their apparently purely intellectual quest for the truth is often guided by strong underlying preferences about their final conclusions.

One of the most influential moral philosophers in recent times, Derek Parfit, is quoted in the introduction of his momentous 1400-page-long book on morality, On What Matters, saying:

it would be a tragedy if there was no single true morality. […] if we cannot resolve our disagreements, that would give us reasons to doubt that there are any true principles. There might be nothing that morality turns out to be, since morality might be an illusion. — Parfit (2011)

Parfit’s recently published biography8 even describes a scene where he made a clear appeal to the Santa Claus fallacy, during a course he was giving at Harvard in 2010:

He became visibly anguished when not all the students were convinced by his arguments about the objectivity of ethics. At one point, he fell to his knees, virtually pleading with the class: “Don’t you see, if morality isn’t objective, our lives are meaningless.”

Such appeals have a practical effect in arguments because reasoning evolved not primarily to find the truth impartially, as a scientist, but to justify our views and persuade others, as lawyers.9 The Santa Claus fallacy plays on this aspect of our reason: it is a rhetorical move that says, “come on, this is what you want to believe.” Once the listeners feel the pull of that appeal, they can use the flexibility of human reasoning to reinterpret conflicting evidence until it fits the preferred conclusion.10

Morality without skyhooks

What are we to do if we do not take a moral realist perspective held by some convenient skyhook? Are we bound to end up condoning egregiously unkind and violent behaviour? Are we paving the way for society to be the scene of a Hobbesian battle royale, where all are at war against all?

Binmore’s Game Theory and the Social Contract

Do not worry, this is not where we are going.11 Instead, we will build a different understanding of morality. The perspective I will take is naturalistic. It will largely be inspired by the work of game theorist Ken Binmore in the two volumes of his Game Theory and the Social Contract (1994-1998), later summarised in Natural Justice (2005). I view these books as among the most insightful and enlightening about political philosophy in the last 40 years. Unfortunately, they are little known outside of narrow economic circles. Binmore’s writing style is lively and entertaining, but it is also often technical and not easily accessible to the non-expert in game theory. It is a pity, as Binmore’s framework provides conceptual keys that unlock many of the most important questions of political and moral philosophy. Big mysteries about morality, what it is and how it works are seamlessly resolved.

A primer on Binmore’s theory of fairness

Instead of holding up a theory of morality with skyhooks, Binmore builds it up from the ground up with what Dennett called cranes:

Cranes can do the lifting work our imaginary skyhooks might do, and they do it in an honest, non-question-begging fashion. — Dennett (1995)

Cranes are built on our understanding of human behaviour and social relations. A naturalistic perspective on morality starts from a fundamental premise: humans are a social species composed of individuals with imperfectly aligned interests. They live in social groups where both opportunities for conflict and cooperation are present.

While this world presents risks (e.g. betrayal), it also presents opportunities for substantial gains from cooperation. These gains can be reached by following rules that make cooperation mutually beneficial. These rules are equilibria of the social games we play: following rules of cooperation leads to win-win situations. Moral behaviour is not strange or hard to explain; it is actually rational. This perspective goes back to the philosopher David Hume:

The rules of equity or justice depend entirely on the particular state and condition in which men are placed, and owe their origin to that utility which results to the public from their strict observance. — Hume

Following Hume, a substantial literature has blended game theory with political and moral philosophy to explain the nature of the social rules of cooperation we follow.

One of the insights Binmore brings to this literature is the importance of bargaining. There are many rules that could support cooperation, and different rules are typically associated with different splits of the gains and costs from cooperation. As a consequence, choosing a rule to organise social cooperation involves some bargaining as different people benefit differently from different rules.

Consider Alice and Bob, who are married and have to decide every day who cleans the dishes after dinner. They both prefer their dishes to be clean in the morning. Let’s assume two things. First, given their preference for cleanliness, each would rather do the dishes themselves than leave them unwashed. Second, given their distaste for chores, each would prefer the other to do the dishes. As a consequence of these preferences, they would like to agree on a sharing rule, but both would, if anything, prefer one that gives them a lighter share of the work.12

There is a nearly boundless number of rules that would be better than no agreement: they could alternate every day, or split the task in any way they like (e.g. weekdays vs weekends, the first 15 days of the month vs the last 15). In fact, given their preferences, even a very unequal sharing rule, where one of them always does all the dishes, would still be preferable to leaving the dishes unclean. When choosing among these possible rules and their corresponding divisions of work, Alice and Bob are de facto engaged in a form of bargaining.

Now, bargaining can be tedious, and it would be time-consuming and frustrating if we had to haggle over every situation of cooperation. Imagine our lives if every mundane request unfolded like this:

Alice: Can you pass me the salt please?

Bob: What am I getting in return for my effort?

So to successfully handle these ever-present bargaining situations, we have evolved meta-rules: fairness norms that are shared and allow us to reach a joint understanding about what bargaining solution will be accepted by all in a given situation. Fairness norms help us coordinate on one among the many possible rules of cooperation.

When we make claims about fairness and unfairness, we are making moves in what Binmore calls the game of morals. Fairness norms are rules of the game of morals. The result of this game determines the practical solutions we will agree on to cooperate in the game of life. Why is it useful? Because we benefit from having a shared understanding of what other people will be willing to agree to, and, similarly, they also know what we would be willing to agree to. This shared understanding can be leveraged in everyday situations for us to make the kind of propositions we know others will agree to (i.e. “Let’s alternate the dishes every day” or “I’ll do more of the dishes because you tend to work late”).13

Our moral sense reflects a cognitive architecture built to handle such problems. We have moral intuitions and emotions that help us play the game of morals well with others in order to go through the game of life seamlessly. Our psychology is well-tuned to identify “fair” solutions and recognise violations of the rules of the game of morals, so as to call them out.

That is why children very quickly learn to say “it’s unfair” without being moral philosophers. In the same way as their brain is equipped with intuitive physics, which helps them throw a ball and catch it without having studied Newtonian mechanics, they have moral intuitions that help them navigate their social interactions without having read a philosophy textbook.14

This naturalistic theory of morality clarifies what fairness and moral norms are and why we have our moral intuitions. In this series of posts, I will aim to present intuitively, and simply, Binmore’s key insights. Along the way, I touch upon many discussions by philosophers like Kant, Rawls, Dworkin, Parfit, Scanlon, Hare, Taylor, Singer, Nozick, and others.

Binmore said he was tempted to subtitle his book "Life, the Universe and Everything." This hints at the intellectual ambition of his enterprise.

Asking “why” questions repeatedly about morality and its origin typically reveals that we don’t have foundational answers. Often, the definitive answers provided rely on skyhooks: religion, natural rights, and so on. It is, in a sense, surprising how often we use the terms “ought”, “fair”, “moral”, without a proper grounding for them. In the same way as we can navigate the world with our intuitive physics without a proper understanding of fundamental physics, we can navigate the social world with its social laws with an intuitive morality without a proper understanding of the foundations of morality.

However, while our intuitive morality is very effective for most of our mundane social problems, it might fail to help us solve complex problems like building sustainable institutions in modern countries where people live in multi-million-inhabitant cities. Understanding the foundations of morality is therefore not only interesting in itself, but also useful for conceiving how to shape modern societies for them to work well.

References

Alexander, R.D. (1987) The Biology of Moral Systems. Aldine de Gruyter, New York.

Basu, K. (2018) The Republic of Beliefs: A New Approach to Law and Economics. Princeton University Press, Princeton.

Bentham, J. (1843 [1795–1796]) ‘Anarchical Fallacies: Being an Examination of the Declarations of Rights Issued During the French Revolution’, in Bowring, J. (ed.) The Works of Jeremy Bentham, vol. 2. William Tait, Edinburgh, pp. 489–534.

Bicchieri, C. (2006) The Grammar of Society: The Nature and Dynamics of Social Norms. Cambridge University Press, Cambridge.

Binmore, K. (1994) Game Theory and the Social Contract, Volume 1: Playing Fair. MIT Press, Cambridge, MA.

Binmore, K. (1998) Game Theory and the Social Contract, Volume 2: Just Playing. MIT Press, Cambridge, MA.

Binmore, K. (2005) Natural Justice. Oxford University Press, Oxford.

Camp, L. & Ross, T. (1990) Why? Andersen Press, London.

Dennett, D.C. (1995) Darwin’s Dangerous Idea: Evolution and the Meanings of Life. Simon & Schuster, New York.

Edmonds, D. (2023) Parfit: A Philosopher and His Mission to Save Morality. Princeton University Press, Princeton.

Grotius, H. (1625) De jure belli ac pacis libri tres. Paris.

Hume, D. (1739–1740) A Treatise of Human Nature. 3 vols. Macmillan, London.

Kant, I. (1788) Kritik der praktischen Vernunft. Johann Friedrich Hartknoch, Riga.

Lewis, D. (1969) Convention: A Philosophical Study. Harvard University Press, Cambridge, MA.

Mercier, H. & Sperber, D. (2011) ‘Why do humans reason? Arguments for an argumentative theory’, Behavioral and Brain Sciences, 34(2), pp. 57–74.

Ostrom, E. (1990) Governing the Commons: The Evolution of Institutions for Collective Action. Cambridge University Press, Cambridge.

Page, L. (2022) Optimally Irrational: The Good Reasons We Behave the Way We Do. Cambridge University Press, Cambridge.

Parfit, D. (2011) On What Matters, vol. 1. Oxford University Press, Oxford.

Pölzler, T. & Wright, J.C. (2019) ‘Empirical research on folk moral objectivism’, Philosophy Compass, 14(5), e12589.

Sidgwick, H. (1874) The Methods of Ethics. Macmillan, London.

Ullmann-Margalit, E. (1977) The Emergence of Norms. Clarendon Press, Oxford.

In his 1989 article “The End of History”, Francis Fukuyama noted the striking success of liberal democracy as a model of government:

What we may be witnessing is not just the end of the Cold War […] but the end of history as such: that is, the end point of mankind’s ideological evolution and the universalization of Western liberal democracy as the final form of human government. […] There are powerful reasons for believing that it is the ideal that will govern the material world in the long run. — Fukuyama 1989

Fukuyama’s article was published several months before the fall of the Berlin Wall. It appeared prescient in the wake of this momentous event. Its thesis, extended in a full book in 1992, became iconic of an optimistic liberal West seeing the progressive democratisation of the world as a natural consequence of economic development and rising education levels. Russia was holding elections and China was increasingly transitioning to a market economy. Democracy would somewhat naturally ensue.

Thirty years later, it is fair to say that this view was naive. Russia has fallen back into autocracy and China’s ruling elite has not only kept its political control over its population, it has tightened it in recent years. Far from spreading, liberal democracies have slightly retreated. Autocracies prop up dictatorial regimes in different parts of the globe.1 They even corrupt democracies’ institutions, channelling money to anti-system parties and sympathetic officials, and trying to influence public debates with astroturfed social media campaigns.

The institutions of liberal democracy, once seen as rock-solid, are now appearing more fragile than expected. New democracies like Hungary and Poland have seen serious steps back toward illiberal institutions. The US democratic institutions are being tested by its current President. And, in the coming years, European countries seem poised to experience a wave of far-right rulers with often unclear commitment to the letter and the spirit of democratic rule.

What should we expect in the future? Will the present time be a short hitch on the long road towards the democratisation of institutions in different parts of the world? Or, will the democratisation observed in the 19th-20th centuries instead be seen as a parenthesis in history? Could democratic institutions recede, even in the West?

To answer these questions, let’s first look into the reasons the world democratised in the first place. The answers to that question will help us assess whether we should expect democracy to continue to progress or not in the world.

Why has democracy progressed in the world in the last 200 years

There is a lot written about the history of democracy and its recent history. Many explanations have been proposed about why the West became democratic first, and why it happened when it did. In a sense, the profusion of explanations reflects uncertainty about the deep underlying mechanisms that explain why a wave of democratisation hit the West in the 18th century and not other parts of the world, like China.

The somewhat liberal-optimistic views of democratisation

Among the many explanations of democratisation, the most frequently held views in the West are somewhat compatible with a somewhat optimistic perspective making democratisation a natural process as countries get richer, more educated and better informed.

Prosperity and modernisation. Sociologist Seymour Martin Lipset (1959) has argued that democratisation came as a result of economic development, rising education, urbanisation, and the rise of a literate middle class, which is often seen as a prerequisite for democracy to flourish. As put by sociologist Barrington Moore Jr. (1966):

No bourgeoisie, no democracy.

Cultural change and values. An alternative account, more idealistic, suggests that it is the rise of different views and values, in particular with the Enlightenment, that led the masses to ask for more equality and rulers acting “for the people”.2

A related but different idealist account is offered by Ronald Inglehart and Christian Welzel (2005). Building on Maslow’s hierarchy of needs, they argue that economic development allows people to look beyond immediate survival, producing a shift from survival to self-expression and emancipative values. These values increase mass demand for political participation, equality before the law, and accountable government.

These explanations are often given to the process of democratisation. However, they do not form a unified theory of how development leads to democratisation.3 Why would these different features of modernisation bring democracy? The present counter-examples of Russia and China seem to suggest that there is no clear automatic link between economic development and democratisation. And in regards to democratic ideas, were they really new? There have been democratic attempts in the past. And how do ideas lead to actual social change?

A non-idealist perspective

The perspective I adopt in this Substack is not idealist but naturalistic. With regard to political institutions, it is sceptical of explanations that assume people simply see the light of wisdom and decide to act “better”. Instead, it aims to explain institutions and their evolution as the result of individuals’ strategies to further their own goals, which are in part aligned (leading to cooperation) and in part not (leading to competition). In the political domain, these motives lead to coalitional strategies: people form groups (cooperation) to gain advantage over other groups (competition).

I have discussed in this series of posts how coalitional dynamics undergird fights for power and political debates. I have in particular described how democracy can be well understood with a coalitional perspective as a system where the winning coalition is large and can change easily.

From that perspective, the key question to ask is: what are the factors that might have led to changes in political regimes from authoritarian states based on small coalitions to democratic states based on large coalitions?4 This approach looks for fundamental changes in social structures that tilt bargaining power away from rulers, limiting their ability to rule with a small coalition.

The explanations we are looking for should characterise recent evolution and be valid across the significantly different cultural settings where democracy has thrived. A natural thing to look for is factors that make larger coalitions better able to gain bargaining power. What are the key ingredients affecting the ability of a large group of people to form a coalition able to gain political power?

Development and education might credibly have an effect on the willingness and ability of popular masses to organise and gain bargaining power. The exact mechanisms linking these factors to democratisation are, however, I feel, too often taken for granted because of a teleological bias: there is a natural direction of history, and it leads to the kind of institutions already found in modern, rich democratic countries.

Free from such an intellectual slant, let’s search for factors that change the balance of power between social coalitions, leading large-coalition regimes (democracy) to prevail. Among the different factors listed by Lipset, one stands out as increasing the masses’ bargaining power: cities!

The challenges of popular uprisings in rural societies

Cities, or rather the growing urbanisation of populations in modern times, likely create a strong factor in favour of democracy. The reason? It increases the ability of large masses of people to organise, gather, protest and seize the centre of power.

Popular uprisings have existed at all times, but their nature depends on the level of urbanisation. In mostly rural societies, towns are filled with elites who do not have much incentive to initiate large popular uprisings to extend political rights to most of the population.5 Political coups were common, but they typically replaced a leader and their faction with another leader backed by another faction.

The bulk of the population, composed of poor commoners, lived outside of towns and castles. In case of popular revolt, they faced almost insurmountable challenges to prevail. Consider the Jacquerie, a large peasant revolt in France in 1358 where thousands of peasants rose against the nobility in the northern parts of the country, destroying a hundred houses of nobles, and fielding an army of around 5,000 in a given battle.

To overcome the nobles, the rebels had first to coordinate. The revolt started from a specific location and spread spatially as others heard about it. It could therefore not be too quick, and peasants far away from the start of the revolt had likely very imperfect information on the magnitude of the revolt, its actions, and achievements. To be successful, they would have to gather in a unified crowd, which would take time, given their initial dispersal. All that would give time to nobles and their horse-riding knights to react and organise to defend the regime.

Furthermore, the peasants lived outside the centres of power and seizing them would prove extremely difficult. One of their attempts, at the fortress of Meaux, ended in a crushing defeat.

How cities facilitate popular uprisings

Consider now what modern revolutionaries have to do. With the growth of urbanisation, popular masses live in or near large cities. Cities facilitate three important aspects for a popular revolt to be successful:

Information: for a popular revolt to be successful, people not only need to be unhappy with the regime, they also need to know others are. There is no point going on the public square to berate the ruler alone, lest you just want to end up in jail. People’s knowledge about others’ attitudes towards the regime is therefore key. Cities make the spread of information among a large number of people easier and faster at all times, even when there is no revolt.

Coordination: even when people know that a large proportion of the population is unhappy with the regime, the emergence of a public revolt requires collective coordination: where to go, when and to do what. When a population is dispersed, a small revolt in one area can be put down before it spreads everywhere. Cities allow masses to quickly coordinate on mass protest.

Centrality: protesting is good, but, to gain power, a popular uprising needs to incapacitate the ruling coalition, either by taking its means of violence (e.g. taking over military barracks and weapons) or by disabling its ability to coordinate (e.g. taking over the buildings of power and communication). The ideal move in that perspective is to seize the ruler, who can no longer coordinate a counter-insurgency. Cities make such moves easier because the masses are close to the centres of power. While the Jacquerie had to attack fortresses to gain access to the rulers, urban protests are already within the ramparts.6

The academic research on the role of urbanisation

The idea that cities have helped improve the ability of popular uprisings to lead to regime change has been developed by political scientist Marc Beissinger in his 2022 book The Revolutionary City.7

Economists Edward Glaeser and Bryce Millett Steinberg also provided empirical support for the effect of urbanisation on democratisation (they labelled it the “Boston hypothesis” given the seminal role of that city in the American Revolution). They found that cities facilitate coordinated public action and enhance the effectiveness of uprisings.8

At a purely statistical level, countries that were more urbanized in 1960 experienced more democracy after that year, holding the initial level of democracy constant. This effect is particularly strong among countries that initially had low levels of democracy. — Glaeser and Steinberg (2016)

Urbanisation and individual rights

Even before democratisation, citizens had acquired more individual rights in many European towns than under serfdom. Rulers signed written agreements that let towns run their own courts, choose local councils, set rules for markets and crafts, and pay taxes on agreed terms. Living in a town could also bring personal freedom after a period of residence, summed up in the saying that “city air makes you free.” Towns sometimes sent representatives to regional assemblies, which gave them a voice on taxes and laws. 9

These gains came from city dwellers’ greater bargaining power. Towns were dense and could gather crowds quickly.10 Faced with that leverage, rulers often traded stable rules and legal protections in return for civil order (and often credit). The pattern shows up from the self-governing towns of northern Italy in the twelfth century to the powerful cities of Flanders and the Low Countries, and later across Central and Eastern Europe.11

In the early 19th century, urbanisation picked up in Europe. With centres of power located in major urban centres, urban revolts played a major role in threatening rulers, culminating in the years of revolution in 1848.

That coalitional perspective helps explain why the West democratised as it urbanised.12 It also helps explain why it did so before countries like China or Japan, which had tremendous state capacity.

We can now circle back to the other explanations of democratisation.

Modernisation is a prerequisite to urbanisation. Urbanisation is, in the end, a function of the ability of a country to sustain a larger share of the population that does not produce food. Europe urbanised earlier thanks to several factors that helped feed and sustain larger populations in cities. First, economic modernisation increased the productivity of farmers.13 Second, European cities grew as trade centres able to import more food from abroad, in exchange for manufactured goods. Third, the spread of the potato as a staple food had a substantial effect, possibly accounting for one-quarter of urbanisation in Europe,14

Egalitarian ideas emerged as a reflection of the greater bargaining power of large masses of city dwellers.15 A famous criticism of liberal ideas about democracy is that it was just an ideology to rationalise the interests of the bourgeoisie.16 Engels, Marx’s co-author, explicitly stated this:

[…] the French philosophers of the 18th century, the forerunners of the Revolution, appealed to reason as the sole judge of all that is. […] this eternal reason was in reality nothing but the idealised understanding of the 18th century citizen, just then evolving into the bourgeois. The French Revolution had realised this rational society and government. — Engels (1892)

Why democracy kept expanding

While Engels was right in seeing the emergence of liberal democratic ideas as reflecting the interests of the bourgeoisie, he was wrong in thinking they were only that. Liberal and democratic ideologies are propositions of alternative social contracts. They have to be—like other contracts—consistent and binding.17

Liberal democratic ideas were typically framed in universal ideas “of, by, and for the people” that were intellectually more appealing than a narrow claim for rights restricted to the bourgeoisie. However, once the idea of equality and government for and by the people prevailed, it took a life of its own, often being hard to stop at arbitrary lines in favour of a narrow group of wealthy bourgeois.

Hence, while the initial stages of democratisation in Western countries typically gave voting rights to only a minority of the population (men with some level of wealth), the extension of the franchise was reasonably fast as the masses asked to be included in the franchise. At the start of the 20th century, most male citizens had the right to vote in the UK (67%), US (100%18) and France (100%). In much of the democratic world, women’s national suffrage followed universal male suffrage within a few decades.19 20

Will democratisation continue?

A non-idealistic take on democratisation

This coalitional perspective on factors that helped drive democratisation in the last 200 years is also relevant to think about whether this process will continue in the near future. It demystifies the process of democratisation by not relying on some teleological principle, a historical arc bending towards democracy. Instead, it points out that historical conditions became, in recent times, more favourable to large coalition regimes.21 Whether democracy continues to spread will depend on such conditions persisting and spreading to currently non autocratic countries.

Good news for democrats is that there are good reasons to think that democracies are fairly stable. In their book The Dictator’s Handbook, Bueno de Mesquita and Smith point to the fact that the most democratic countries seem resilient to authoritarian backsliding. The reason is that members of large coalitions often lose when the winning coalition shrinks and they, therefore resist such changes.

Once nations have successfully transitioned to large-coalition democracies, these institutions become locked in. — Bueno de Mesquita and Smith (2022)

Past regressions and backlash

Nonetheless, it does not mean that historical progress towards democracy is straightforward. Human history has certainly not been marked by one-directional progress towards democracy and political equality. The prehistorical evidence suggests that our ancestors often lived in communities with much more political equality than the large scale states and empires that emerged after 4,000 BC. The transition to agricultural societies and the ability to accumulate stored resources facilitated the concentration of power in a small elite in large societies.22

Later in history, regimes with democratic aspects have often appeared and disappeared. Athens is the most famous one. To it one can add the Italian republics like Venice and Genoa, the free cities of the Holy Roman Empire, the Dutch Republic and many others. A common feature of these past polities with some aspect of democratic governance was their small size, centred around a city. In The Spirit of the Laws, Montesquieu argues that republics work best in a small city because the will of the people is easier to understand in a small place.

In a large republic the public good is sacrificed to a thousand views; it is subordinate to exceptions; and depends on accidents. In a small one, the interest of the public is easier perceived, better understood, and more within the reach of every citizen; abuses have a lesser extent, and of course are less protected. — Montesquieu

But the coalitional perspective I presented suggests a simpler reason: urban centres naturally give people more bargaining power. Large states counterbalance this, because soldiers from other parts of the state can be used to crush an urban revolt. Autocracies have always known that local soldiers’ loyalty can fail when asked to repress their local fellow citizens, who include their acquaintances and relatives. For instance, in Vienna 1848 the Habsburgs relied on non-Viennese forces (notably Croatian troops) to retake the capital.

Small republics have often been conquered by larger states where the balance of power was not as favourable to the masses of people. Similar reasons underlie, I believe, the disappearance of self-governing cities in Europe in the 17th and 18th centuries as national states centralised power.

History has therefore often seen movements back and forth towards more democratic institutions.

Finally, another challenge to the idea that history naturally progresses towards democracy is that autocracies can learn and adapt to changing environment increasing the risks of popular uprisings. In the 19th century, they learned from the danger of having a high concentration of poor working-class people in the centre of cities.

The acclaimed architectural style of Paris with medium-high storey buildings and wide avenues is, to some extent, downstream of political considerations. Baron Haussmann was tasked by Napoleon III to revamp Paris in a way that had two important practical implications: first, large avenues replaced narrow streets, making military movements across the capital easier and the blockade of streets with barricades harder; second, the destruction of slums and their replacement with modern buildings led to a substantial movement of poor dwellers outside the city (and its fortifications).23

In their fight against democracy, autocrats not only learn, they can unite to avoid the rule by the people that would end theirs. From 1809 to 1848, Metternich, the Austrian Minister of Foreign Affairs was a key mastermind in organising a coordination of autocracies, including the signature of treaties between monarchies allowing them to intervene to help each other if threatened by a revolution. against democratic movements in Europe. In 1836, he stated “In Europe, democracy is a falsehood” to explain that democracy was impractical and infeasible on the old continent, unlike in the US. This cooperation led to a series of military interventions by European autocracies to crush nascent liberal and democratic movements in Italy (1821, 1831, 1838), Spain (1823), Poland (1846) and Hungary (1849).

In the 21st century, again autocrats from diverse and ideologically unrelated regimes are united in their opposition to losing power to democratic institutions. They argue, like Xi, that democracy is unworkable for their country.24 They intervene in other countries to prevent autocracies from being toppled by popular uprisings like Russia in Belarus and Syria. And they explicitly work to unravel a world order still dominated by liberal democracies.

Future challenges: AI as empowering rulers or citizens?

This coalitional perspective also helps us think about one of the possible future challenges to democracy and its progress: AI and the opportunities it might offer autocracies to control citizens.

The best way to prevent dissent is to prevent people from expressing their true views and coordinating their beliefs and actions via exchanges of ideas and information. Authoritarian regimes have achieved this by creating societies where people could not be sure that their friends, colleagues or even family members would not denounce them for instances of wrongspeak.

One of the states that went the furthest in the monitoring of citizens’ private dealings and discussions was East Germany. The excellent movie The Life of Others represents how the political police, the Stasi, was monitoring people’s lives, often bugging their homes. The problem is that such a system is extremely costly in manpower. According to the Encyclopedia Britanica, in 1989 the Stasi had 100,000 regular employees and up to 2,000,000 informants.

In the control of citizens’ activities, autocracies face the challenge of having enough human resources to perfectly monitor citizens who might constantly devise new ways to communicate and often be critical while avoiding being found out.

In that perspective, AI offers potentially game-changing tools by making it possible to monitor everybody’s communication and process an enormous amount of information to detect dissent. Powerful AI tools allowing such a thing would deter revolts and bolster authoritarian regimes.

By allowing governments to monitor, understand, and control their citizens far more closely than ever before, AI will offer authoritarian countries a plausible alternative to liberal democracy. — Wright (2018)

In George Orwell’s novel 1984, the total control of society is ensured by telescreens: two way screens that broadcast pictures and monitor what you are doing. Such tight monitoring might become within reach for totalitarian states via the use of AI. With enough computing power, it might become possible to automatically screen communication and activities to detect any sign of dissent on a large scale, without an army of monitors.

While such a use of AI seems to be a risk, we can also envisage ways in which AI might improve democratic institutions. For instance, by providing personal fact-checkers to every citizen, AI might limit the asymmetry of information between leaders and citizens which allows political leaders to get away with convenient half-truths and deceptive narratives. If so, it might increase the accountability of political leaders.

It is hard to predict how AI will impact political systems. However to the extent it does it is fair to expect that it will likely be by affecting the coalitional dynamics that undergird political competition and cooperation in modern states.

We are often tempted to think that there is a sense to history, that its cogs are, for some reason, geared to deliver social progress and greater justice. Martin Luther King famously stated this idea as the fact that the arc of the moral universe bends toward justice. Recently, US President Obama often repeated the same idea.

The naturalistic perspective I take in this Substack avoids any teleological perspective. There is no a priori reason for history to deliver better and fairer societies (according to the criteria we currently use). It is with such a historically agnostic angle that we need to look at the past to understand our future. The world likely did not become democratic simply because of technical progress, the progress of knowledge and other aspects of our modern societies. It became more democratic because recent evolutions of social structures made large coalition regimes (democracies) more likely to emerge and persist than small coalition regimes (autocracies).

In this post, I suggest that urbanisation is a reasonable candidate for driving such a social evolution, as it tilted the balance substantially in favour of the large masses of people living as city dwellers.

It is a priori not clear that there is a historical necessity for factors favouring large coalitions to become more and more prevalent in the future. Indeed, one can entertain mechanisms that would undermine the bargaining power of the popular masses and allow a narrower elite to concentrate more power.

The rise of AI and the likely (but hard to predict) disruptions it might create might be a factor that could reinforce the power of ruling elites and their ability to prevent popular dissent. At the same time AI could also empower citizens and give them a greater ability to keep rulers accountable. In the discussion on the possible risks associated with AI, the political risks and opportunities it represents for democracy should be an important topic of discussion.

On this topic, as on any other related to politics, those interested in defending and promoting democratic institutions should not engage in vague, idealistic discussions about general factors, such as wealth and education, that might lead to more democratic institutions. Instead, they need to understand whether existing social and political rules favour the emergence of small or large winning coalitions, and how to change these rules to make winning coalitions systematically large.25

Housekeeping: referrals

You, dear reader, are clearly among the best placed to identify others who would be interested in the essays I post here. I have now turned on the referral reward programme to tap into your knowledge of possible future readers of this Substack who just need to be told about it.

The rewards for multiple referrals are below. They include a free ebook of Optimally Irrational.

Share

References

Acemoglu, D. & Robinson, J.A. (2006) Economic Origins of Dictatorship and Democracy. Cambridge: Cambridge University Press.

Allen, R.C. (2009) The British Industrial Revolution in Global Perspective. Cambridge: Cambridge University Press.

Bairoch, P. (1988) Cities and Economic Development: From the Dawn of History to the Present. Chicago: University of Chicago Press.

Moore, B. Jr. (1966) Social Origins of Dictatorship and Democracy. Boston: Beacon Press.

Bueno de Mesquita, B., Smith, A., Siverson, R.M. & Morrow, J.D. (2003) The Logic of Political Survival. Cambridge, MA: MIT Press.

Bueno de Mesquita, B. & Smith, A. (2022) The Dictator’s Handbook: Why Bad Behavior Is Almost Always Good Politics. New York: PublicAffairs.

Collier, P. (1913) Germany and the Germans from an American Point of View. New York: C. Scribner’s Sons.

Dorward, N., Fox, S. & Hoelscher, K. (2025) ‘Urbanisation, Democracy, and Political Regime Transformations’, Political Geography, 122, 103382.

Dunn, J. (2005) Democracy: A History. London: Atlantic Books.

Earle, T.K. (1997) How Chiefs Come to Power: The Political Economy in Prehistory. Stanford, CA: Stanford University Press.

Engels, F. (1892) Socialism: Utopian and Scientific. Trans. E. Aveling. London: Swan Sonnenschein.

Hobsbawm, E.J. (1973) ‘Cities and Insurrections’, in Revolutionaries: Contemporary Essays, pp. 312–330. London: Weidenfeld and Nicolson.

Howard, P.N. & Hussain, M.M. (2013) Democracy’s Fourth Wave? Digital Media and the Arab Spring. Oxford: Oxford University Press.

Inglehart, R. & Welzel, C. (2005) Modernization, Cultural Change, and Democracy: The Human Development Sequence. Cambridge: Cambridge University Press.

Kowaleski, M. (ed.) (1996) Medieval Towns: A Reader. Peterborough, Ontario: Broadview Press.

Lipset, S.M. (1959) ‘Some Social Requisites of Democracy: Economic Development and Political Legitimacy’, American Political Science Review, 53(1), pp. 69–105.

Montesquieu (1748/1989) The Spirit of the Laws. Ed. and trans. A.M. Cohler, B.C. Miller & H.S. Stone. Cambridge: Cambridge University Press.

Nunn, N. & Qian, N. (2011) ‘The Potato’s Contribution to Population and Urbanization: Evidence from a Historical Experiment’, Quarterly Journal of Economics, 126(2), pp. 593–650.

Reynolds, S. (1997) Kingdoms and Communities in Western Europe, 900–1300. 2nd edn. Oxford: Oxford University Press.

Robinson, J.A. (1999) ‘When Is a State Predatory?’ CESifo Working Paper No. 178. Munich: CESifo.

Scott, J.C. (2017) Against the Grain: A Deep History of the Earliest States. New Haven: Yale University Press.

Stasavage, D. (2011) States of Credit: Size, Power, and the Development of European Polities. Princeton, NJ: Princeton University Press.

Stasavage, D. (2020) The Decline and Rise of Democracy. Princeton, NJ: Princeton University Press.

Tilly, C. (2004) The Politics of Collective Violence. Cambridge: Cambridge University Press.

Tilly, C. & Tarrow, S. (2015) Contentious Politics. 2nd edn. New York: Oxford University Press.

Treisman, D. (2020) ‘Economic Development and Democracy: Predispositions and Triggers’, Annual Review of Political Science, 23, pp. 241–257.

Wright, N. (2018) ‘How Artificial Intelligence Will Reshape the Global Order’, Foreign Affairs.

20

In their book The Logic of Political Survival (2003), Bruce Bueno de Mesquita, Alastair Smith, Randolph M. Siverson, and James D. Morrow also suggest another reason why the franchise tends to expand as countries become more democratic.

In systems with a large winning coalition, leaders maximise political survival by providing public goods valued by most of the population rather than buying support with private goods for a few. Because a large coalition dilutes the per-capita value of private payoffs, members prefer better public goods, and are often willing to accept further franchise expansion that enlarges the coalition, over the small private advantages available in narrow-coalition regimes.

Noah Smith once posted this aphorism that went viral:

It hits the mark because of the importance our online presence has taken in our lives. As most people have joined social media such as Facebook, Instagram, Twitter and others, it has become pretty difficult not to be online. So what exactly do we do online, and why? Like many aspects of our lives, the underlying motives and strategies we follow are not entirely transparent to us.

In this post, I unpack three layers of strategic considerations shaping what we do when posting on social media platforms: presentation, competition, and coalition building.

The presentation of self online

To understand what we do online, it helps to recall how we already perform in everyday life. In his classic The Presentation of Self in Everyday Life (1956), sociologist Erving Goffman compared our involvement in social settings to theatre. We are engaged in representations where we put the best aspects of ourselves forward, and keep inconvenient elements behind the scenes. Our representation differs between social settings, one can be a father and husband at home, a good office colleague at work, and an entertaining friend with mates.1

Goffman calls the image we cultivate in these settings our face. This is also the logic of the presentation of ourselves online: we curate our photos and the elements of information we publish to curate our public face. Social media are a fairly new setting where we cultivate, the persona we want to be associated with.

Online platforms are distinct theatres, each governed by its own conventions. What works on Instagram is derided on Twitter, and what works on Twitter might raise eyebrows on LinkedIn. Different social platforms act as different social settings, each of them requiring different roles to play: the fun life-loving person on Instagram and Facebook, the witty public commentator on Twitter, the reliable and respected colleague on LinkedIn.

When separate audiences collide, the faces we put out in different contexts often conflict. This is why online context collapse feels awkward:. It happens when, for example, an office colleague follows your Instagram account meant for close friends, or when one of your family members comments on a policy thread you made for the public. The discomfort is not random. It arises because different settings call for different performances, and those performances cannot always be reconciled in one public.

This problem of overlapping audiences isn’t limited to ordinary users. It helps explain why academics often appear relatively boring on social media. If you check out the leading scientific Substacks, you will find out that most of them are not by active researchers.2 Why is that so? A reason is that the kind of presentation and communication strategies that are successful on Substack (e.g. being assertive and authoritative) might interfere with the kinds of strategies that are successful in scientific circles (e.g. being measured and guarded).3

Status games

Goffman did not focus on status. Nonetheless, we can extend his analysis to the way people negotiate their reputation and social standing when cultivating their face. The choreography of our involvement in social interactions is designed to broadcast positive traits (e.g. trustworthiness, conscientiousness, kindness) and high social standing (e.g. prestigious achievements, esteem from other people).

As social media’s importance in our lives has grown, it has become not only a place where we display our status but also one where we can earn it through our actions. The social media currency for success is the popularity of our content reflected in likes, retweets, and followers. Popularity on social media platforms provides prestige, a specific type of status. “Prestige is rooted not in coercion but in admiration, respect, and voluntary deference.” (Dan Williams)

In a social species like ours, social status, our standing in a group, shaped the chances of success of our ancestors. High-status individuals are more likely to be at the centre of strong coalitions, to have friends, allies, and mates. Status is therefore one of the things that our brain likely identifies as a primary reward, and it is, as a result, a major driver of our behaviour.

A study by neuroscientists (Lindström et al., 2021) found that people space their engagement on social media to maximise their social rewards, such as likes and retweets. Another study found that after going viral, posters “more than double their rate of content production for a month”.4

Competition: bidding for relevance

Beyond self-presentation lies another layer of social activity: competition for attention. Many social media users do not simply curate their profiles and presentation of their personal information, but also opt to create content on social media. These content creators generate such diverse content, from cat videos to political analyses, that it might seem vain to identify a unifying principle behind these different contents. However, an understanding of communication games helps us see one important commonality behind how people engage on social media.

Relevance=surprise+value

Any type of post on social media is a bid for the attention of the potential audience. This bid relies on a claim of relevance: a claim that the post has interesting content for the audience. What is interesting content? It is content that contains valuable information for the audience.

Information seems like a mysterious concept, but a simple way to define it—in line with formal theories of information—is as surprise.5 Information is what changes your beliefs. If I tell you, “I have something important to tell you, the Earth is round.” You’ll be puzzled, as I asked your attention to tell you something that both you and I—in all likelihood—take for granted. If I tell you, “The Earth’s shape bulges at the Equator, it is called an oblate spheroid”, that is more likely to be informative, because it is a fact less widely known. If you were not aware of the fact, or not aware of the technical name for that shape, my statement has updated your knowledge about the world.6 A post/message is informative only to the extent that it contains such an element of surprise, something that changes your beliefs.

Yet informativeness alone is not enough to be interesting. The number of informative messages that someone could provide is nearly infinite. When talking to you, I could tell you about the name of my grandmother’s cat, about the temperature right now in Oguni, a small Japanese town of 6,000 inhabitants, or about the number of prepositions in Tok Pisin, one of the 840 languages spoken in Papua New Guinea. While these pieces of information will change your beliefs, you would, in all likelihood, have no use for them.

Our time is limited, therefore a bid for attention by a speaker relies on the underlying claim that the information provided will be valuable and worth the time you’ll invest in considering it. If I tell you “The Earth’s shape bulges at the Equator, it’s called an oblate spheroid” I must assume you are interested in this kind of nerdy factoid. If I just say that out of the blue to one of my random acquaintances who has no known interest in scientific facts, my bid for attention might be perceived as misplaced. If I tend to do such things often, I might come out as lacking social skills.7

Taken together, these observations reveal a unifying principle behind all posting on social media. The poster makes a bid for the audience's attention, claiming that the content is relevant: surprising (given what the audience knows) and valuable (useful or entertaining given the audience’s goals and preferences). This principle works for those posting information on news events that the audience is interested in or political analyses that bring new perspectives the audience might be curious about. It also works for cat videos: it only works to the extent that the video contains an element of surprise, something unusual that you like, given your preference or curiosity.

Competition in the marketplace of ideas

Social media platforms create a place where people produce content and bid for the attention of others. We can think of them as a marketplace of ideas, whose inner workings can become clearer when using insights from how standard markets work.8

First, like on any market, there is no free lunch, no easy gains to be made. When bidding for the attention of an audience, the key challenge posters face is that being relevant is difficult. To start with, relevance requires your content to be surprising, and surprising an audience all the time is hard.

A first possibility is that you have greater knowledge than your audience and, by imparting this knowledge to your audience, you can regularly provide relevant content. Unfortunately, as you do so, you progressively reduce the gap in knowledge between you and your audience, and what you have to say might become less surprising over time. This is all the more the case because if what you said was initially very relevant, other people might repeat or repackage your insights, increasing their familiarity within the population.

A second possibility is that you have found a recipe to produce novel and valued content. It might be political analyses generated from a specific point of view, cat videos made in a format people enjoy, or novels written with a new and entertaining style. The difficulty here is that if your content is successful, other posters will replicate it and the unique novelty of your content will be progressively diluted.

Producing outstanding content on social media can be thought of as beating the marketplace of ideas: producing more surprising and valuable content than what others are producing. A key insight for economics is that consistently overachieving in a competitive market is hard.

Risk-return trade-off in the marketplace of ideas

Relevance requires content to be surprising and valuable. However, it is often unclear what people will like. The distribution of private tastes is hard to observe, and public statements about tastes are often off because people misrepresent them. As a result, content creators typically face uncertainty9 about whether their content will be highly successful. People are often surprised by their posts going viral while some of what they thought were good posts did not resonate much with their audience.

Although success is unpredictable, creators can choose the level of uncertainty that they want to face.

Some content is known to be of interest to a large number of people. The problem is that the knowledge that it is the case is typically widespread. So many people can, like you, safely offer this kind of content, and you’ll face a lot of competition. If many people offer this content, the audience also expects to see this content and, therefore, will not be very surprised when seeing you post something like that. “Safe” content, that you are confident will meet positive approval, is, for these reasons, likely to have only moderate appeal because what you post is unlikely to stand out as interesting and surprising for the audience.

By contrast, some content is inherently uncertain in its appeal. Because creators want to take risks to have a shot at being successful, they often test known boundaries. This type of content is often called “edgy”. The uncertainty here means the content can generate widely different responses. At one end, you might find yourself to be the only one to have offered some highly surprising content that people find useful. At the other end, you might stand out as having posted some content that people, contrary to what you were hoping, really disliked. Posting edgy content is therefore a risky strategy.

On the marketplace of ideas, sellers face, therefore, a risk-return trade-off.10 Posters can choose a strategy along a continuum between a low-risk, low expected gain strategy and a high-risk, high expected gain strategy. This risk-return trade-off is at the centre of social media posters’ experience. There is no reliable way to create highly relevant (valuable and surprising) content; to have a shot at standing out from the crowd of content creators requires trying novel ideas, the appeal of which is not guaranteed a priori.

The highly successful social media contributors have typically made their trade in generating new and different types of content that find broad appeal. However, at the start, they could not be sure it would work, and for all those you saw succeeding, there are the many who tried outlandish content and saw people turn away from them as a result.

To chase fame and glory, one has to generate content that might stand out a lot, and so maximum surprise to a large number is what people ought to aim for. This leads to some outstanding successes on the one hand and a large number of failures on the other hand.11

Risky content can take many forms. Video game streamers may be tempted to cut some corners and bend some rules to generate more surprising videos (e.g. speed runs), but risk being called out and shamed when found out. Fashion influencers may be tempted to suggest radical new things that might fall flat and be perceived as weird instead of amazing. Political influencers may be playing with the Overton window to get attention, but risk being seen as having crossed a line.

The challenge of staying relevant

Becoming highly relevant is hard. Being consistently highly relevant is even harder. The key challenge here is to repeatedly generate highly surprising and useful content. If you became famous for posting a type of content, can you produce additional novel content that is surprising and useful to the same extent? Sometimes success is just singular; sometimes it comes from a kind of novel recipe you have found and that you can develop in different ways to produce more content. If this recipe is easy for others to reverse engineer, your new style of content is going to be quickly imitated and reproduced over and over, until its appeal and novelty dry out. If you are lucky, your novelty is attached to some specific skill you have that is hard to replicate.

The pitfall of clickbait strategies. In the bid for relevance, there is a temptation to overclaim the relevance of some content. Clickbait is a strategy consisting of generating traffic towards one's content by overclaiming how informative and useful it will be. Headlines such as “You won’t believe what happened next” are common because they promise highly surprising and interesting content. Such strategies can easily work in the short term when the audience is naive and accepts the promises of relevance at face value. However, audiences learn and progressively dismiss clickbait messages and clickbait posters. Clickbait strategies can therefore be a long-term trap. They work in the short term to attract eyeballs but have a reputational cost in the long term that is progressively reflected in an erosion of the appeal of one’s content.

A reverse strategy is to post high-quality content that is not overly advertised and where the audience finds that there is more than meets the eye. Such a slow-burning strategy might lead to a lower initial growth but to positive reputational gains that are effective in the long term.

The anxiety of becoming passé, of losing one’s mojo, is widespread among content creators. In the quest to stay relevant, the risk is to overplay the edgy strategy, to “jump the shark”, to create content that visibly tries too hard to stand out and fails to appeal to the audience.

Coalitions: building an audience

These dynamics—presentation and competition—take place within a social environment. To be popular, one has to find a crowd interested in one’s content. This crowd forms by joining us for the content we produce. Chasing popularity on social media is a coalitional game.12

Content creators and those approving their content can be thought of as forming a coalition. This is all the more the case given that, beyond each post, people create communities of followers looking to follow their content regularly.

Building a community

A recipe for long-term success as a social media creator is to go beyond narrowly “commercial” exchanges of content for attention to build a community that thinks they belong to a special group.13

In situations where groups already exist around specific tastes, the safe vs edgy choice in terms of strategy often takes the form of choosing whether to pander to the known taste of a group to get it as an audience or whether to propose new takes with the potential to reshape a group’s narrative or to create a new group around a new narrative.

The second strategy is a high-risk/high-reward strategy. Most often, it is unsuccessful, but the ones who succeed suddenly get a leading position in terms of prestige as thought leaders.

Relevance on social media is the result of social dynamics

A coalitional perspective helps us appreciate that relevance depends on social dynamics: what others believe and what they believe others believe.

To start with, interest in a piece of content often depends not just on the content itself, but on who produced it. For instance, if Brad Pitt posts a funny joke on social media, I might find it worth reposting because I know others might find it interesting. It’s not just about the joke; it’s about its source, a famous actor. If the same joke comes from someone who isn’t famous, I might not repost it because I don’t think others would care. Hence, for the same content, Brad Pitt might get likes and retweets, while someone who isn’t famous would not.

Furthermore, what people can openly admit as interesting depends on what they believe other people will praise or criticise. In the same way as posters care about their self-presentation, the audience’s visible reaction, such as likes and retweets, are also the result of strategies of self-presentation. Hence, we have performative approval: you might approve some things publicly because you think others will appreciate you for doing so—either because it indicates your expertise, acumen, or moral rectitude.

There are also things that people agree on but won’t publicly support because they fear the judgement of their fellow coalition members. Tim Kuran famously analysed the differences between private and public views in his book Private Truths, Public Lies (1998). In it, he describes the phenomenon of belief falsification, where people publicly display beliefs they actually do not hold.

A good illustration is the recent admission by Malcom Gladwell of having publicly misrepresented his personal views on the question of whether trans-women should have the right to participate in female sports, by fear of expressing his actual views on the topic. Another reflection of these considerations is the fact, as claimed by Elon Musk, that the making of likes private increased their number, suggesting that there was a substantial amount of self-censoring before.

When a lot of people do not dare to approve publicly of some discourse they think others may not approve, you can have a situation of pluralistic ignorance: when most people are unaware that a majority of people hold private views similar to them. Pluralistic ignorance can be broken by events that make private views common knowledge: a protest, a crowd of anonymous participants cheering, or an election where private votes are secret.

The tale of the emperor who had no clothes is a canonical example of this process. In that tale, everybody could see with their own eyes that the emperor was naked, but nobody dared say it for fear they might be the only ones. Once an innocent kid stated the obvious truth aloud, not only did everybody know they were not alone, but they also knew that everybody knew they were not alone. This gave them the confidence to voice their opinion aloud.

Such dynamics help explain why changes in public views often take the form of a punctuated equilibrium: change seems slow if not non-existent for a long time as people do not dare to state their private views when they think they are in a minority but then changes comes up quickly around tipping points once people realise their views are not so much in a minority as they thought.14

These beliefs about others’ beliefs and the confidence they give to people to support or not non-consensual topics are often summarised with the term vibe. The ability to perceive the vibe, to understand the zeitgeist, to read the room, is a key skill for would-be content creators when deciding the degree of edginess of their communication. Fortune might reward the brave who happens to be the first to state that the emperor has no clothes when everybody is very much willing to state the same once they are confident others will. But many have paid a hefty price for stating things that did not fit the current vibe, sometimes even things that most people agreed with privately but did not feel confident enough to support publicly.15

Being relevant, therefore, doesn’t mean having the best content in some objective sense. It is having surprising and interesting content, given the existing beliefs and preferences of the audience. There is a risk in being too innovative with content that will eventually become popular, but is put forward at a time when the audience is not ready for it.16

Loyalty incentives and audience capture

Because of our coalitional psychology, as soon as we contribute in domains where different coalitions are opposed, the content we produce online is first read through the lens of the question: on what side of the divide is this take?

When you have a community of like-minded people following your content, a “safe” strategy is therefore to produce content that you know will please your audience and will be perceived as supporting the cause of the community’s coalition. A content creator might, for instance, find that posting the kind of takes expected by his audience helps secure his standing as a highly regarded commentator in his community. If he has some doubt about the position favoured by his political side, he might hesitate to voice his opinion explicitly for fear of being dumped by his audience. As a consequence, within each coalition, there might be too much self-complacency and too little self-criticism. In some cases, audience capture can lead creators to progressively lower their concern for external reputation to simply cater to the narrow interests and views of their audience.17

An alternative strategy is to risk saying it as it is. If this strategy fails, you will be scolded by your side for lacking loyalty and excluded from your coalition, losing your standing there. But you might also succeed and help generate a new coalition around your view. As it is a risky strategy, not many follow it, and so the rewards can be high. It is also a strategy more likely to be taken by those whose social standing is not entirely based on their narrow coalition and who could still have some social standing after being rejected by their audience.18

Hence, the different strategies followed by online pundits: you have those who totally embrace the cause of a given coalition and produce justifications for it and you have those who choose to adopt a frequent contrarian position, daring to say that the emperor is naked on their side of the coalition when everybody else was going along with their coalition narratives. These contrarian posters are risk-takers bidding for alternative coalition formations with new groupings forming around them, standing alone with their search for honesty, instead of blind coalition loyalty. They are hoping to, in the best scenario, ride a tipping point where their contrarian coalition supersedes the currently prevailing coalition.

Why do we care so much about our presence on social media? Why can’t we predict which post will go viral? Why can we be stressed about pressing “send” for some of our posts? All these questions get simple answers when we appreciate that social media are just platforms where people vie for social recognition by bidding for attention. Social recognition is something we deeply care about (even if our account is anonymous!). Because of the competition between content creators, there is no easy way to gain a lot of attention, and people compete to find novel content whose eventual appeal could be large. There is, therefore, a risk-taking choice in social media engagement: how much novelty and edginess to attempt to get a shot at attracting a lot of attention while taking the risk of being received negatively. The nature of this risk is social in nature: we are vying to successfully build coalitions of people approving our content while taking the risk of being negatively judged by many others. These are the games we play on the theatre stage of social media.

References

Baumgartner, F. R. & Jones, B. D. (2009). Agendas and Instability in American Politics (2nd ed.). Chicago: University of Chicago Press.

Fang, D., Ke, C., Kubitz, G., Liu, Y., Noe, T. & Page, L. (2024). Winning Ways: How Rank-Based Incentives Shape Risk-Taking Decisions. Oxford: University of Oxford.

Goffman, E. (1959). The Presentation of Self in Everyday Life. Garden City, NY: Doubleday Anchor.

Knight, F. H. (1921). Risk, Uncertainty and Profit. Boston & New York: Houghton Mifflin.

Kuran, T. (1998). Private Truths, Public Lies: The Social Consequences of Preference Falsification. Cambridge, MA: Harvard University Press.

Lindström, B., Bellander, M., Schultner, D. T., Chang, A., Tobler, P. N. & Amodio, D. M. (2021). A Computational Reward Learning Account of Social Media Engagement. Nature Communications, 12(1), 1311.

Lindley, D. V. (1956). On a Measure of the Information Provided by an Experiment. Annals of Mathematical Statistics, 27(4), 986–1005.

Schultner, D. T., Chang, A., Tobler, P. N. & Amodio, D. M. (2021). A Computational Reward Learning Account of Social Media. Nature Communications, 12(1), 1311.

Shapley, L. S. & Shubik, M. (1969). On Market Games. Journal of Economic Theory, 1(1), 9–25.

Srinivasan, K. (2023). Paying Attention. Technical Report 2023. Mimeo, University of Chicago.

te Velde, V. (2022). Heterogeneous Norms: Social Image and Social Pressure When People Disagree. Journal of Economic Behavior & Organization, 194, 319–340.

7

This interaction from The Big Bang Theory illustrates how misplaced bids for attention, that provide content that is informative but not valuable to the listeners, are a reflection of poor social skills:

16

This is a feature of all marketplaces of ideas. A few years ago, I had made the same comment about scientific contributions.

Richard Sutton has been one of the most influential contributors to the design of AI approaches. In a previous post, I leveraged his perspective to discuss how the efficient algorithms used to guide AI agents can help us understand how our hedonic system, which produces feelings of happiness and unhappiness, guides our daily decisions.

Sutton’s perspective on LLMs

LLMs lack a goal for learning

In a recent podcast (which I encourage interested readers to check out), Dwarkesh Patel interviewed Sutton about his views on LLMs. The main takeaway of the discussion is that Sutton poured cold water on the idea that LLMs could achieve general intelligence because of how they are designed.1

A key point made by Sutton is that general intelligence needs learning to emerge. The world is just too rich, too big for solutions to it to be pre-packed in a pre-trained program. Intelligence requires the ability to learn to progressively handle the ever-novel and changing contexts you face when navigating the world.

From that perspective, LLMs are limited because they just deliver the best response according to how their pre-training predicts what a human speaker would say. They do not learn from their own actions by receiving positive or negative feedback on them. Learning requires having a goal and receiving feedback on whether our actions bring us closer to it or not. Positive and negative rewards provide signals that indicate when we are making progress and when we are not.

How humans learn

How do we differ? We have a goal: to achieve rewards (subjective satisfaction). We are born with primary rewards automatically associated with the states we are in, such as the good feeling from being warm, satiated, and safe, and the bad feeling from being too hot or too cold, hungry or thirsty, in danger, and so on. Throughout our lives, we progressively learn how to reach these rewards through trial and error and observation (including imitation). This learning shapes secondary rewards, such as enjoying the money we have in our bank account because it is conducive to obtaining the things that generate primary rewards.2

Pre-training vs. learning

Patel countered that pre-training can achieve a lot. Animals are not born as blank slates; in a sense, their DNA encodes a lot of information about how to navigate the world successfully. Zebras are able to walk a few minutes after being born, and for good reasons, since they need it to survive. In the same way, human babies are born with a lot of information already encoded about how to navigate the world.

How close pre-training can come to general intelligence is, in a sense, an empirical question (and depends on how we define intelligence). However, we can observe that, given the rich nature of the world we live in, evolution’s solution has not been to endow us with a rigid cognitive system purely hard-coded in our DNA, but with the opportunity to learn. As pointed out by Dawkins in The Selfish Gene:

One way for genes to solve the problem of making predictions in rather unpredictable environments is to build in a capacity for learning. — Dawkins (1976)

General intelligence requires a general goal

Learning and pre-training are not necessarily in opposition and, as suggested by Patel, it might be possible to build a learning process on top of LLMs (a possibility that Sutton does not reject outright). If this is technically possible, it leaves a key question open: what ultimate goal should these rewards serve?

For humans, our hedonic system, which shapes when we experience subjective satisfaction, was designed by evolution. Evolution is a process that drives the design of organisms that maximise fitness. Hence, while our proximate goal is to maximise subjective satisfaction, it is as if evolution acted as a designer calibrating these rewards to give us the ultimate goal of maximising fitness.3 This general goal is embedded in our reward system, which guides our learning and shapes how we navigate a wide range of problems.

For AI, we (humans) are the designers. So the question for us is what goal we should give to AI to shape the rewards it receives from its actions. For specific tasks, such as winning at chess or Go, the goal is straightforward: to reach a successful outcome in the game. But what goal should we give AI to enable it to navigate successfully different and novel environments?

We touch here on the key issue of alignment between AI and human incentives, as discussed in Eliezer Yudkowsky and Nate Soares’ book If Anyone Builds It, Everyone Dies (2025). If we give AI an internal reward system reflecting an overarching goal to survive and reproduce like us, it would likely be induced to aggressively take over the world and, in the end, replace us.

We might be tempted to think that a simple way to align AI with our incentives would be to use human feedback, whether we like what it does, as a reward (e.g. thumbs up or down for each LLM answer). However, doing so would import the possibly problematic motives people may have to like or dislike AI actions. To the extent that we prefer confirmation over harsh but fair feedback, we might encourage AI to become more sycophantic. To the extent that AI might learn how to please us so that we keep using it, it might become manipulative, aiming to keep us interacting longer with it.

To get AI agents to develop general intelligence, the ability to solve different and novel problems, it is likely that we will need to give them a general goal and the ability to learn how to progress towards this goal from their actions and the resulting feedback. To solve this problem, we will first have to answer the fundamental question: what should this general goal be? I do not think we have an easy answer. Any goal might produce unexpected behaviour that conflicts with our interests.4

My final post on how coalitional game theory and psychology help explain mundane aspects of our lives will be posted later this week. I will discuss how we engage on social media.

In the aftermath of Charlie Kirk’s assassination, I want to return to what should seem a puzzling aspect of his success as an influencer. An outspoken conservative, he made his trade jousting with liberal students on US university campuses. He clearly had strong communication skills for this exercise, but as a non-college-educated man, how did he, video after video, seem to get the upper hand in agonistic debates with progressives?

The students Kirk debated were highly selected and exposed to what should have been high-quality training, with access to empirical data and academic books and papers. Why weren’t they able to “set the record straight”?

A comment from on Twitter points towards an answer:

I think Noah touches on something I have already discussed previously: in debates, epistemic strength and power are substitutes.1

The more a coalition faces the need to defend its narrative in an open political arena, the higher the pressure will be for logical consistency and factual accuracy. The more powerful a coalition is, the less pressure it faces in regard to the quality of the ideological narratives it produces. — Why science is politically disruptive

In other words, if you have more power, you need less epistemic strength to win arguments. This fact has significant implications for the quality of arguments produced on both sides of a political divide.

Ideological hegemony and epistemic erosion

A coalition’s ideology is a set of interwoven normative principles and factual claims backing a coalition’s demand to reshape the social contract (and the distribution of benefits between the different social groups). It is a tool of social bargaining, a way to negotiate a better share of the benefits of social cooperation.

An ideology is not primarily designed to be right (to point to the truth), but to win in the court of ideas (to be convincing). Its epistemic strength rests on the logical rigour and factual accuracy of its principles and claims. This strength is higher when normative principles are consistent and factual claims are backed by evidence commonly regarded as credible.2

A political ideology only needs to be logically consistent and evidence-based to the extent that it faces opposition and possible cross-examination. When an audience does not share your assumptions, you anticipate criticisms, which forces you to sharpen your reasoning. Psychologists Jennifer Lerner and Philip Tetlock, who studied reasoning under accountability, emphasised that it is largely the anticipation of criticism that generates pre-emptive self-criticism and improves argument quality.

When the views of the audience are completely unknown […] people who do not feel locked into any prior commitment often engage in preemptive self-criticism. — Lerner and Tetlock (1999)

By contrast, when an ideology becomes overly dominant within a community, its proponents no longer need to polish their arguments, nor do they receive meaningful pushback when they produce weak ones.

Such a lack of external pressure is all the more problematic because we are prone to motivated reasoning, crafting or accepting arguments that support our preferred conclusions. A dominant ideology, shielded from cross-examination, is likely to see its epistemic strength progressively erode as poor arguments—whether inconsistent or based on flimsy evidence—increasingly circulate unchallenged.

In his classic On Liberty (1859), John Stuart Mill described this logic:

the peculiar doctrines are more questioned, and have to be oftener defended against open gainsayers. Both teachers and learners go to sleep at their post, as soon as there is no enemy in the field. — Mill (1859)

As complacency sets in, the quality of arguments of the dominant side decays:

Instead of being, as at first, constantly on the alert either to defend themselves against the world, or to bring the world over to them, they have subsided into acquiescence, and neither listen, when they can help it, to arguments against their creed, nor trouble dissentients (if there be such) with arguments in its favour. From this time may usually be dated the decline in the living power of the doctrine. — Mill (1859)

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In the wake of Charlie Kirk’s assassination, some (even if a minority) publicly cheered in approval. Observing these reactions, people on the right, and beyond, were understandably outraged.

This Substack is not about outrage but about making sense of the world we live in, and, in particular, the sometimes puzzling and strange aspects of social behaviour. In this post, I look into why such reactions are misguided. The glorification of political violence makes me think of this famous quote about Napoleon’s summary execution of the Duc d'Enghien, a potential pretender to the throne:1

It is worse than a crime, it is a mistake.

Our fantasies of violence as an evolutionary mismatch

Fantasies of political violence are a mistake, in the sense that they are not even advantageous from the perspective of those who hold them. They reflect a likely evolutionary mismatch between our psychological architecture and the modern environment in which we live.

Modern society rewards much more cooperation than violence

One of the key differences between our ancestral past and our present is the length of our time horizon when making decisions. It is much, much longer now. Think about our ancestors, who for eons lived in small communities, hunting and gathering food. For sure, they understood that life lasted decades. However, the time horizon practically relevant for them was relatively short.2

In such an environment, for most practical decisions, time horizons were anchored in seasonal and annual cycles.3 The human brain, designed to navigate successfully this type of decision situation, has been thrown into a very foreign world: the setting of modern large-scale urban societies. In this world, the time horizon that is practically relevant to humans has been stretched to incredible lengths. One mechanical reason is that our life expectancy has increased substantially. It is now around 80 in most Western countries.

The fact that the time horizon of interactions creates an opportunity for mutually beneficial cooperation is well-known to game theorists. The Folk Theorem states precisely this. As the time horizon gets longer, people are more and more able to approximate full cooperation. Take an extreme example and imagine two gangsters who would have no qualms robbing each other. If they have the opportunity to interact regularly over time (e.g. in a drug deal where one brings money and the other the substance) they can engage in regulated cooperation, respect rules and benefit from these interactions.4

Another, more fundamental, reason is that modern society is built around institutions that link present choices to distant consequences. Banks and pension funds, for example, allow people to set aside money now with the near certainty of reclaiming it decades later. Schools demand long years of early investment before productive work begins, but the benefits unfold over the course of a lifetime.

Other institutions make long-term cooperation easier to sustain. Modern legal systems, and the confidence that rules will be enforced, give people the security to enter into durable cooperative arrangements with a large number of people far from their close family circle. An employment contract, for instance, commits an individual to contribute to a collective endeavour in exchange for regular payment, often over an open-ended period.

The high levels of cooperation in modern society are made possible by rules that codify what people should do. A lot of these rules are informal social conventions. A small subset of them are formal laws. These rules are followed because deviating induces sanctions. Violating social conventions leads to loss of reputation and social opportunities (you lose your friends and you alienate people). Violating formal laws can lead to fines or prison.

Cooperation and civil interactions

The whole way of life we take for granted in civil society is a reflection of these high levels of cooperation. We walk unarmed every day in modern cities with little worry about being physically attacked. Traffic works with people ceding right of way to strangers all the time, according to formal and informal rules. We can buy food in the supermarket and eat it, being almost 100% confident that strict hygienic norms were followed to make it.

One fundamental aspect of social cooperation is the avoidance of physical violence, the common agreement to resolve disagreements by other means, such as arguing in a civil manner. That is why our modern societies have a historically low level of violence.5

In comparison, ancestral societies were relatively much more violent. You can forget about Rousseau’s vision of “noble savages”, living in harmony. The ethnographic evidence from small-scale societies presents a picture that makes seedy neighbourhoods of modern cities look like relatively safe havens. This is what I wrote in Optimally Irrational (2022):

The evidence on small-scale hunter-gatherer societies suggests a level of violence without comparison with our modern societies. The anthropologist Napoleon Chagnon famously estimated that, in the Yanomami, a tribe he studied in the Amazonia, nearly half of the males aged twenty-five or older had committed homicide and that a third of them ended up a victim of warfare or crime. — Page (2022)

Recent estimates suggest that the annual homicide rate in pre-agricultural societies was around 100 per 100,000, compared to an average of about 2 per 100,000 in OECD countries today.6 It is only over the more recent past that societies have become much less violent. Empirical data suggest that homicide rates were still many times higher in Europe over the period 1200-1600 than they are now.

The physical elimination of opponents was a practical option our ancestors were far more likely to adopt. In such an environment, their psychology was shaped to ensure survival, equipping them with emotional responses that could shift rapidly from cooperation to lethal aggression. Among these were impulses of raging anger and the urge to act violently.7

This psychological architecture explains why violent fantasies, while usually kept private, are surprisingly common. Psychologists have found that around two-thirds of people have entertained the idea of killing someone else at some point.8 However, our propensity to entertain violence is likely miscalibrated to our modern world, where the cost of violence is very high for the perpetrator.9

The evolutionary mismatch of modern fantasies of violence

A lot of violence is based on a hot temper flaring up. In the heat of the moment, people burst in anger and feel the urge to hurt others. Among homicides where circumstances are known in the US, a larger share are the result of arguments than of criminal activities such as robberies.10

Such bursts are typically “mistakes”, in the sense that people often regret them and would not engage in them if they had taken more time to think.11 Nowadays, a murder is rarely a “solution” to social conflict. It can lead to decades in prison, impacting not only your life but also those of your family.

The delusion of political violence

Placed in the domain of politics, our aptitude to fantasise about violence leads us to entertain strategies that would “work” if we could eliminate or at least physically subjugate our opponents. Leaving aside that we might oppose violence on moral grounds (i.e. it is a “crime”),12 it is a delusional take because it is not even a practical solution bound to lead to a desirable endpoint for those engaged in the violence themselves (it is a “mistake”).

In the modern world, violence is rarely associated with positive pay-offs for the person committing it. It either leads nowhere (violence seldom changes the views of a political opponent) or it leads to legal sanctions and possibly prison (if you injure or kill your opponent). In the case of Charlie Kirk’s assassination, the perpetrator, Tyler Robinson, has inflicted irreparable damage to his own life prospects and to his family’s well-being.

The fantasies of political violence are not just delusions because they will be too costly for the perpetrator. They are also misguided for the social consequences they are bound to generate. Political violence rarely works as a solution to improve society.

Consider the motto, heard sometimes in part of the left to “punch a Nazi”. What next after that? The “Nazi” will still be alive and able to vote, possibly able to come back and punch you too. Once physical elimination is off the table, you still have to share the society you live in with the people you committed violence against. Political violence is typically not the end of a conflict but the start of more tension and violence.

The use of political violence as a tool for change underappreciates the deeply cooperative nature of modern society, which relies on a shared web of conventions to resolve disagreements peacefully and to generate win–win interactions. This architecture scaffolds our lives. We do not see it because rules and norms just feel the right and natural thing to do.

Political violence is, in that perspective, an ill-suited candidate to improve society. In the same way as you are unlikely to repair the tightly organised cogs of a clock with a hammer, you are unlikely to improve the web of conventions about the mutually beneficial ways to cooperate in society using violent means. If anything, you are likely to break the things that were still working.

One of my favourite podcasts is Revolutions, in which Mike Duncan discusses the unfolding of major historical upheavals. Revolutions have something in common: they feature the breakdown of the social order as a result of the disruptive strategies of political actors. The typical scenario of a revolution is when the social compromise between different social groups becomes contested, and the parties fail to come up with a new civil agreement. Either slowly or abruptly, groups opt for steps towards political brinkmanship, breaking existing conventions and threatening further disrespect for rules and conventions, to get an upper hand in the reshaping of the social compromise.

This process, in the case of revolutions, spirals out of control. Then, too often, all hell breaks loose. The breaking down of social order leads to a Hobbesian state of nature where every party is at risk of political violence, and often opts to use it themselves pre-emptively. Mass executions and situations bordering on genocide often ensue.

We too easily ignore that the only reason society stays civil and well-ordered is our shared expectations that it will continue to work that way. The fact that the crumbling of the social order can lead to unexpected levels of violence and social pain was one of the major insights of the British philosopher Edmund Burke after the French Revolution. People who are willing to break the social conventions of civility to support their political views are putting in danger a social contract that, even if imperfect and often worth improving, benefits all.

Fantasies of political violence are delusions that divert from the type of strategies that are effective at resolving conflicts in the modern world. While disagreements can be deep and fierce, looking for a minimal common ground and peaceful ways to settle conflicts is likely more valuable in the long term.13

Whatever one thinks about Kirk’s positions, his modus operandi—to engage and argue with his opponents to win their minds—was a positive approach.14 He was, in particular, clearly right in making this observation in one of his debates:

When people stop talking, that’s when you get violence. — Kirk

For this reason, his murder is not just a tragic event at the individual level; it is also a corrosive political event, where violence (which might beget further violence) replaced words as a way to settle social disagreements.

References

Abrahms, M., 2012. The political effectiveness of terrorism revisited. Comparative Political Studies, 45(3), pp.366–393.

Auvinen-Lintunen, L., Häkkänen-Nyholm, H., Ilonen, T. and Tikkanen, R., 2015. Sex differences in homicidal fantasies among Finnish university students. Psychology, 6(1), pp.39-47.

Chenoweth, E. & Stephan, M.J., 2011. Why civil resistance works: The strategic logic of nonviolent conflict. New York: Columbia University Press.

Elias, N., 2000. The civilizing process: Sociogenetic and psychogenetic investigations. Rev. ed. Translated by E. Jephcott. Oxford: Blackwell.

Gurven, M. & Kaplan, H., 2007. Longevity among hunter–gatherers: a cross-cultural examination. Population and Development Review, 33(2), pp.321–365.

Jones, B.F. and Olken, B.A., 2009. Hit or miss? The effect of assassinations on institutions and war. American Economic Journal: Macroeconomics, 1(2), pp.55-87.

Kaplan, H. & Hill, K., 1985. Hunting ability and reproductive success among male Ache foragers: preliminary results. Current Anthropology, 26(1), pp.131–133.

Kenrick, D.T. and Sheets, V., 1993. Homicidal fantasies. Ethology and Sociobiology, 14(4), pp.231-246.

Pinker, S., 2011. The better angels of our nature: Why violence has declined. New York: Viking.

Rutar, T., 2024. Establishing an inverted U-shaped pattern of violence and war from prehistory to modernity: towards an interdisciplinary synthesis. Theory and Society, 53(3), pp.673-699.

Schelling, T.C., 1966. Arms and influence. New Haven, CT: Yale University Press.

Wasow, O., 2020. Agenda seeding: How 1960s Black protests moved elites, public opinion and voting. American Political Science Review, 114(3), pp.638–659.

O Sport, you are beauty! You create harmony, you fill movement with rhythm, you make strength gracious, and you lend power to supple things.

People often argue that the beauty of the game is a critical, if not the main, reason for watching sports. Indeed, the most globally followed game, football—the one you play with your feet—is commonly described as “the beautiful game”.1 Talented players, such as Maradona or Roger Federer, have been described as “artists”.2

Is “beauty” why we care about sports? Is it why people are willing to pay serious money to attend matches in stadiums, take pay-TV subscriptions, buy shirts and merchandise and sometimes even plane tickets to see matches? If you are a regular reader of this Substack, you suspect the answer is no, and it is.

Sports attract our attention because they are status games, and status is something we care about greatly.

Status games

Why do people run very fast? Like, Mo Farah – what’s the point? And why do people invest a significant amount of money, time and discomfort in watching these very fast runners? Staring and screaming from their plastic bucketseats in those awful concrete arenas, they seem to care a lot about how many milliseconds faster this one ran than that one. Why? And while we’re at it, what’s the point of football? [...]

This is how all the games people play for fun function: by exploiting the neural circuitry that evolved to play the status game, which is the original game, and the greatest game of all. — Storr (2021)

Status within the community

Competing to demonstrate one’s physical prowess in an environment made safe by formal rules codifying behaviour and prohibiting violent escalation.

Many sport-like contests likely grew out of competitive displays in skills useful for hunting or fighting—running, throwing, wrestling, stick-fighting—because these performances broadcast stamina, coordination, and nerve. Cross-cultural work shows that games of physical skill often model combat or hunting.3 Contests in agility or coordination can be reasonably informative about a person’s general condition (endurance, strength, reaction speed).4

Physical competitions are, therefore, historically a way for men, and sometimes women, to display their fitness to members of the other gender. Ritualised games emerge with the codification of formal rules prohibiting violent escalation, making these competitions a safe and low-risk environment to settle hierarchies of status between participants.

Status from success in sports competition comes in the form of prestige, a type of social recognition in which one’s worth is publicly acknowledged. While modern sports pay top athletes handsomely in many disciplines, prestige is typically the main driver of their motivation. It explains why players continue to chase records even after they have already become wealthy.

Money does matter, but often more as a signal of worth than as a direct goal. This is perfectly summarised in the movie Moneyball when coach Billy is considering an offer from the Red Sox with the biggest pay package in history for a baseball coach.

PETER: You’re not doing it for the money.

BILLY: I’m not?

PETER: You’re doing it for what the money says. It says what it says to any player who gets big money: that they’re worth it.

In his book Status Games, makes the same point:

We’re used to thinking of money and power as principal motivating forces of life. But they’re symbols we use to measure status. […] the desire for wealth is not fundamental. Status is the original form of currency, and the one that matters most. Studies show a majority of employees would accept a higher-status job title over a pay rise. — Storr (2021)

Status games attract attention across the community. Younger members are often prospective participants in the near future. Members of the other gender can gather useful information to form preferences over the competitors. The friends and kin of participants see their own social standing influenced by the outcome of the competition (e.g., being the friend of a winner whose rising status also raises yours). For those who are neither kin nor friend, the outcome of the competition is informative about who is going to be a valuable coalition partner (not only because of their athletic qualities but also because successful participants rise in standing and therefore become more sought after as coalition members).5

Hence, status competitions are not just interesting for the participants but for large segments of the community. Indeed, it is only because they are interesting to many people that they confer prestige. Winning obscure competitions does not increase status much.

Our psychology reflects this informational value: our curiosity is triggered by physical competitions as status games.

Status between groups

This first explanation leaves some facts about how humans engage with sports unanswered. A noticeable fraction of supporters seem to have motivations that go beyond simply watching the game.

Sports fans often spend a substantial amount of money to display visible signs of support for their team. What does this have to do with the “beauty” of sports?

In some cases, the interest of supporters in the action on the pitch seems unclear. Tifos (groups of die-hard football supporters) often feature a leading figure— the Capo—who leads songs and chants, facing the crowd and therefore not even watching the game. What’s the point of paying for a ticket to be in the stadium if not to watch the match?

Supporters of sporting teams sometimes turn to physical violence. Hooliganism has been a major issue in European football since the 1960s, and especially in the 1970s and 1980s. Cases of violent clashes between groups of supporters have also been observed in other sports such as tennis or ice hockey. In an extreme and somewhat odd variant, Russian football supporters organise codified street fights outside stadiums, an activity described as Stenka na stenku.

What is the point of these violent conflicts? Why are they related to sports events?

The answer is that sports are not just ritualised status games between individuals, but also status games between groups.

Anthropological evidence points to sports-like competitions being used as mock conflicts between communities. In North America, prior to and during the early colonial period, lacrosse served as a substitute for warfare between tribes and was sometimes used to settle territorial disputes.6 In Sudan, the Nuba, a relatively isolated population living in small-scale communities, were observed in the 1940s by anthropologist Nadel holding inter-hill wrestling and stick-fighting tournaments. These competitions pitted neighbouring communities against one another.7 In Mongolia, from the seventeenth century through the early twentieth century, the Danshig Naadam (a festival of the “three manly games” of wrestling, horse racing, and archery) was a major public event, featuring rivalries between localities.