Thank you for this brilliant article and for introducing his work - a must read . I never knew about Trivers work.but it comes ontime for me. I am working on understanding the behavior of fear and its conflict with judgement
So, senior year at UCSC I moved into a house on High St across the street from the university. It had been his house, we got lots of his mail. Plus they left things.
Regardless, not being a socio/anthro/psych major, I hadn't heard of him so I started reading about this and psychobiology. It was a memory shock to see this article.
Great article. I was Bobs PhD student at Rutgers. One error you make in your article is on parental investment “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. — Trivers (1972)”. This was an error commonly known as the Concorde fallacy i.e. past investment should have no bearing on future investment decisions. Bob acknowledged this error later too. It doesn’t negate the main findings or theory but it does affect optimal investment decisions under various conditions
Hi Robert, thanks a lot for your comment! I think you are right that Trivers’ argument, as stated in that passage, sounds problematic from the point of view of economics, where we would call this a sunk-cost fallacy. I had the same hesitation when writing it, but felt that the intuition might still make sense in a biological setting.
Your comment led me to look into the issue more carefully. With limited resources to allocate across present and future reproduction, past and future investments are not independent. An individual who has already invested a great deal in producing an offspring may have reduced future reproductive prospects, which can make completing the current reproductive attempt more attractive than abandoning it and starting a new one. In that sense, the relevant point is not the sunk cost as such, but the way past investment changes the expected return of future options.
So I agree that Trivers’ wording is open to the sunk-cost criticism. But I also think there is a forward-looking version of the argument, formalised later in the literature, that recovers part of his intuition.
A huge amount of economics is concerned with expectations of future returns, which affect investment today. With money as the sole measure, sunk costs of past investments vs opportunities of new investments are essentially independent. With relationships & offspring, every culture ensures that prior commitment fulfillment has some relationship with expected success of current & future commitment. Most often outside of mere money.
Adding non-monetary variables to econ equations makes reality even more intractable, requiring more heroic assumptions for simplification.
Great to hear from you. Glad you liked the article!
What I meant is the following. Economics is a science of optimal decisions. Lionel Robbins’ famous definition of the discipline was the science of the best allocation of resources to meet unlimited needs. Evolution is an optimisation process. It leads to organisms designed to maximise fitness. So there is a natural alignment between economics and evolutionary theory. You can use all the tools for optimal decisions in economics to understand behaviour if you assume that the ultimate goal (driven by evolution) is fitness.
Trivers’ work focuses on strategic interactions, and even though this approach is not formal, his insights were really good and they often align very well with results in game theory. For instance, I described in my previous post the close parallel between the game theory of cooperation in repeated interactions and his theory of reciprocal altruism. https://www.optimallyirrational.com/p/the-game-theory-of-cooperation
Truly one of the GOATs. The fact he isn't standard reading in virtually all social sciences is a tragedy. Hopefully, decades from now he will be remembered as one of the visionaries that the world wasn't ready to accept.
Yes Trivers was a brilliant man. I enjoyed “The Folly of Fools” very much even though he beat around the bush on self-deception’s role in “homosexuality.” And it’s a pity that he spent so much time with Epstein.
He was great, sure. But I don’t get all the people calling him the greatest evolutionary biologist of the past century. Ronald Fisher and J B S Haldane are definitely greater, as they united genetics with the theory of natural selection. George C Williams, W D Hamilton, and Ersnt Mayr probably were more important too.
Quote: "There is a modern version of group selection which avoids this pitfall: multilevel selection."
Isn't it enough that we evolved in small groups of closely related kin such that the people we grew up around were as a rule close enough genetically to justify altruism. Proximity in other words was a good proxy for relatedness.
I don’t know about a theory making this point quantitatively. I think the best explanation is “cultural group selection”. Some groups coordinate on better social equilibria and thrive with more cooperation. In these groups, conditional altruism is the best policy because it is an equilibrium of the game. Hence there is no negative selection of altruist, but positive selections of people able to engage in altruism but not naively and unconditionally. This idea is present in my previous posts and I will have a dedicated post about it at some point.
There’s no logic to behavior, there’s only the social semiotic which is hidden in language so deeply, that Aristotle easily describes our behavior as contradictory yet noted in reality there are no contradictions. Absent a solution for this key paradox, any sideways explanations like Trivers's only serves to hide contradictions, rather than explain them.
Thank you for this brilliant article and for introducing his work - a must read . I never knew about Trivers work.but it comes ontime for me. I am working on understanding the behavior of fear and its conflict with judgement
So, senior year at UCSC I moved into a house on High St across the street from the university. It had been his house, we got lots of his mail. Plus they left things.
Regardless, not being a socio/anthro/psych major, I hadn't heard of him so I started reading about this and psychobiology. It was a memory shock to see this article.
Great article. I was Bobs PhD student at Rutgers. One error you make in your article is on parental investment “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. — Trivers (1972)”. This was an error commonly known as the Concorde fallacy i.e. past investment should have no bearing on future investment decisions. Bob acknowledged this error later too. It doesn’t negate the main findings or theory but it does affect optimal investment decisions under various conditions
Hi Robert, thanks a lot for your comment! I think you are right that Trivers’ argument, as stated in that passage, sounds problematic from the point of view of economics, where we would call this a sunk-cost fallacy. I had the same hesitation when writing it, but felt that the intuition might still make sense in a biological setting.
Your comment led me to look into the issue more carefully. With limited resources to allocate across present and future reproduction, past and future investments are not independent. An individual who has already invested a great deal in producing an offspring may have reduced future reproductive prospects, which can make completing the current reproductive attempt more attractive than abandoning it and starting a new one. In that sense, the relevant point is not the sunk cost as such, but the way past investment changes the expected return of future options.
So I agree that Trivers’ wording is open to the sunk-cost criticism. But I also think there is a forward-looking version of the argument, formalised later in the literature, that recovers part of his intuition.
YES!!!! This is exactly what saves his argument. As you point out "past and future investments are not independent."
A huge amount of economics is concerned with expectations of future returns, which affect investment today. With money as the sole measure, sunk costs of past investments vs opportunities of new investments are essentially independent. With relationships & offspring, every culture ensures that prior commitment fulfillment has some relationship with expected success of current & future commitment. Most often outside of mere money.
Adding non-monetary variables to econ equations makes reality even more intractable, requiring more heroic assumptions for simplification.
Looks like I need to read more on Trivers.
This is an excellent article. Thank you. Could you elaborate on your point about how Trivers’ work aligns with economics?
Hi Danny,
Great to hear from you. Glad you liked the article!
What I meant is the following. Economics is a science of optimal decisions. Lionel Robbins’ famous definition of the discipline was the science of the best allocation of resources to meet unlimited needs. Evolution is an optimisation process. It leads to organisms designed to maximise fitness. So there is a natural alignment between economics and evolutionary theory. You can use all the tools for optimal decisions in economics to understand behaviour if you assume that the ultimate goal (driven by evolution) is fitness.
Trivers’ work focuses on strategic interactions, and even though this approach is not formal, his insights were really good and they often align very well with results in game theory. For instance, I described in my previous post the close parallel between the game theory of cooperation in repeated interactions and his theory of reciprocal altruism. https://www.optimallyirrational.com/p/the-game-theory-of-cooperation
Perfect. Thank you. I intuited that as I’ve an economics degree. But I wanted to see if the intuition was correct.
It’s a really good article.
Truly one of the GOATs. The fact he isn't standard reading in virtually all social sciences is a tragedy. Hopefully, decades from now he will be remembered as one of the visionaries that the world wasn't ready to accept.
Great post, thanks for writing it!
Yes Trivers was a brilliant man. I enjoyed “The Folly of Fools” very much even though he beat around the bush on self-deception’s role in “homosexuality.” And it’s a pity that he spent so much time with Epstein.
What is self reception role in homosexuality?
By default, I would not think there is much of a role for self-deception in it.
He was great, sure. But I don’t get all the people calling him the greatest evolutionary biologist of the past century. Ronald Fisher and J B S Haldane are definitely greater, as they united genetics with the theory of natural selection. George C Williams, W D Hamilton, and Ersnt Mayr probably were more important too.
Thank you
Quote: "There is a modern version of group selection which avoids this pitfall: multilevel selection."
Isn't it enough that we evolved in small groups of closely related kin such that the people we grew up around were as a rule close enough genetically to justify altruism. Proximity in other words was a good proxy for relatedness.
I don’t know about a theory making this point quantitatively. I think the best explanation is “cultural group selection”. Some groups coordinate on better social equilibria and thrive with more cooperation. In these groups, conditional altruism is the best policy because it is an equilibrium of the game. Hence there is no negative selection of altruist, but positive selections of people able to engage in altruism but not naively and unconditionally. This idea is present in my previous posts and I will have a dedicated post about it at some point.
There’s no logic to behavior, there’s only the social semiotic which is hidden in language so deeply, that Aristotle easily describes our behavior as contradictory yet noted in reality there are no contradictions. Absent a solution for this key paradox, any sideways explanations like Trivers's only serves to hide contradictions, rather than explain them.