Sam Harris speaks with David Buss about the differential mating strategies of men and women. They discuss the controversy that surrounds evolutionary psychology, the denial of sex differences, cross-cultural findings in social science, the replication crisis in psychology, the biological definition of sex, why men and women have affairs, ovulatory shifts in mate preference, sex differences in jealousy and infidelity, the sources of unhappiness in marriage, mate-value discrepancies, what we can learn from dating apps, polyamory and polygamy, the plight of stepchildren, the “Dark Triad” personality type, the MeToo movement, and other topics. If the Making Sense podcast logo in your player is BLACK, you can SUBSCRIBE to gain access to all full-length episodes at samharris.org/subscribe. Learning how to train your mind is the single greatest investment you can make in life. That’s why Sam Harris created the Waking Up app. From rational mindfulness practice to lessons on some of life’s most important topics, join Sam as he demystifies the practice of meditation and explores the theory behind it.
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Today I'm speaking with David Buss.
David is a professor of psychology at the University of Texas at Austin, and he's the author of many books, most recently, When Men Behave Badly, The Hidden Roots of Sexual Deception, Harassment, and Assault.
And David and I get into many interesting topics around the differential mating strategies of men and women.
We discussed the controversy that surrounds evolutionary psychology, the denial of sex differences that one increasingly encounters on the left, cross-cultural findings in human psychology, the replication crisis in psychology,
And then we get into the differences between men and women with respect to the relevant attitudes toward sex and mate preferences, sex differences in jealousy and infidelity, the sources of unhappiness in marriage, mate value discrepancies, what we can learn from dating apps, polyamory and polygamy, the plight of stepchildren,
And the so-called dark triad personality type that causes so much mayhem, the Me Too movement, and related topics.
Anyway, I hope you enjoyed this conversation as much as I did.
All very useful stuff to understand.
And now I bring you David Buss.
I am here with David Buss.
David, thanks for joining me.
Glad to be talking to you, Sam.
So, you have written a very interesting book.
You've written several books, but the current one is When Men Behave Badly.
The Hidden Roots of Sexual Deception, Harassment, and Assault.
When did you start writing this?
Was this a Me Too response?
No, not at all.
Well, first of all, I've actually been researching conflict between the sexes for about three decades, so I published my first paper on it about 30 years ago.
And no, I started writing a book and signed a contract for it At least a year before the Me Too movement broke.
So it's a long-term project.
Took me about three years to write, 30 years to research, three years to write.
Well, it's really interesting, and it connects with so many topics that are of perennial importance, but seemingly even more important now.
But before we get into the specific topic of biological sex and the differential mating strategies of men and women and all of the logic there, perverse and otherwise, Let's just talk about the scientific context in which we're having this conversation.
This is essentially evolutionary psychology that is the lens through which you're looking at these phenomena.
Evolutionary psychology has been and probably still is somewhat controversial.
Can we rehearse the reasons why that's the case?
I think that it's controversial primarily among people who don't really understand its logic.
So people pick up, you know, I don't know, a newspaper article on it, or even in the textbooks that cover it, and all intro to psychology textbooks cover it, they typically contain conceptual errors, typically many conceptual errors.
And so I think there's just a lack of accurate understanding of what evolutionary psychology is, and I think part of that stems from, you know, in my field, which is psychology, you can get a bachelor's, a master's, or a PhD without ever taking a single course in evolutionary biology.
And so, what it means is that all the professors, you know, don't have any training in it, And they don't have a deep understanding of it.
Now, of course, some do.
Some pick it up post-PhD or get some exposure to it.
But one way to think about it is that, I mean, the term evolution, we can start there with some, you know, why things are controversial.
I like to say sometimes that evolutionary psychology is an equal opportunity offender.
in the sense that on the political spectrum, it offends some on the religious right who don't believe in evolution or evolution as applied to humans.
And it offends some on the political left who erroneously, I believe, perceive that if they're evolved, in this case, sex differences in mating strategies, then that will interfere with social justice goals.
Like we want to eliminate discrimination against women, for example, want to eliminate Sexual harassment in the workplace and so it is perceived that well if it's evolved it's inevitable it's ineluctable there's nothing we can do about it and that's just simply a conceptual error a misunderstanding of the field.
And then i guess one of the reason it's controversial in the modern environment is that.
I and other evolutionary psychologists conceptualize, theorize, and empirically document evolved sex differences in, in this case, our mating psychology or sexual psychology.
And we're in a, you know, an era where some people believe, it's what I call sex difference denialism.
And they don't want there to be sex differences.
If there are sex differences, they don't want them to be evolved sex differences.
And then the final ingredient, so I have it all here and especially in this new book, is that it deals with controversial topics.
So in this case, in the case of the new book, sexual harassment, sexual coercion, sexual deception.
It deals with hot topics that are controversial and that people care about a lot.
They have strong emotions You know, to these topics alone.
And so when you combine this mixture, evolutionary theory, sex differences, and then the nature of these hot topics, it's a very combustible mix, and I think generates some controversy for that reason.
Yeah, it's fascinating, this commitment to denying sex differences.
I get the commitment to denying evolution.
That's just theologically mandated, certainly in an Abrahamic context.
So there's not much of a mystery there, but this denial of sex differences, even when it works to the... I guess I understand the initial logic that you think any admission of sex differences will work to the disadvantage of women, but even in those cases where the denial of sex differences obviously works to their disadvantage,
There are no brakes on this crazy train and people, usually on the left, just keep denying that there's any basis for distinguishing men from women apart from their self-designations in the end, right?
It's like a blank slate dogma coupled to an identity politics that takes as its only fulcrum what someone wants to say about themselves on any given Tuesday.
Yeah, and I'm hoping that my book will break through some of these attitudes, precisely for the reason that you mentioned, Sam, is that denying sex differences in these contexts, for example, sexual harassment, some of the topics we'll get into, actually does harm women.
We know, for example, that the more extreme forms of sexual violence are largely perpetrated by men and women are the primary victims of it.
And so my argument is that we really need to understand the underlying sexual psychology of men and women and how they differ in order to eliminate some of these problems, which are genuine problems.
Yeah, yeah.
So, I guess there are a few other pieces here that could explain a bias against evolutionary psychology.
There's one you close the door to in several places in your book.
There's the naturalistic fallacy, the idea that Explaining things in terms of evolutionary logic could be mistaken for saying that because this is the way things have been, and we can tell a story that there were adaptive advantages in the past to our ancestors for human nature taking this turn, we're therefore justifying, in this case, these differences in mating strategies between men and women.
Say, we're saying it's a good thing because it's a natural thing, Of course, no one is saying that, or at least I haven't met such a person, and yet that's an obvious misunderstanding.
It is, and it is astonishing to me how frequently people do jump to that fallacy.
But I think that there's some hope, at least for some people, because you mentioned my other books.
The first book that I wrote was The Evolution of Desire, Strategies of Human Mating.
And one guy who read it told me that understanding men's evolved desire for sexual variety helped him to stay more faithful to his wife because he found himself attracted to women who were other than his wife and initially concluded that, well, maybe I'm not in love with my wife anymore.
But once you realize, no, there are actually two different sets of psychological mechanisms, desire for sexual variety and also the emotion of love, which I think evolved in the context of long-term pair bonding, which characterizes a lot of human mating.
And so I think understanding doesn't automatically lead to that, oh, it's inevitable and there's nothing we can do about it because it's, quote, natural.
And one other element on that is, and this example illustrates this, I think, is that humans have a large number of evolved psychological adaptations, and at any moment in time, only some small subset is activated.
And so we can keep certain adaptations quiescent, unactivated.
We can activate those that we think are desirable to activate.
But the issue of what exists and what should exist from a moral or ethical perspective, those are two different issues.
Yeah, I guess there's also the concern that an evolutionary explanation ignores the role of culture, which of course it need not because we have evolved at least for some considerable period of time in the context of culture and there's an evolutionary description of how culture changes as well, you know, whether that's
more than an analogy to genetic evolution is something people can argue about, but this has a similar Darwinian dynamics.
So, you know, before we jump into specifics, what can we say about the role of culture here?
Because it's been widely alleged that much psychological research has been done on so-called weird people, you know, white, educated, industrialized, rich, democratic people, and therefore has ignored the diversity of people on offer across the planet, and therefore it can't really generalize its results to all of humanity.
Given what we're about to talk about, how concerned should anyone be that that's the case?
I think that evolutionary psychologists in general are less guilty than other social scientists in that.
And so, I mean, one of the first studies I published on mating psychology involved 37 different cultures, many of which were decidedly non-weird.
And also, as I talk about in the new book, some of the sex differences, for example, in the psychological design of sexual jealousy have now been replicated in a large number of more traditional cultures.
Brooke Skelza out in California, I think, I don't know if she's in your neck of the woods or not, but she did a study of 11 different cultures and replicated the sex differences.
So, you know, if you look at the cross-cultural evidence, which, you know, is difficult to gather, but it accumulates year after year, there is strong empirical support, at least for a number of hypotheses about that have been advanced, and in particular those centering on human mating.
It sounds like this is not the epicenter of the replication crisis in psychology, but how concerned are you about the replication crisis?
Is that affecting any of what we're going to talk about, and just how much is that casting a shadow on any of the work you have done or are doing?
We should probably remind people what we mean by replication crisis.
I've mentioned it a few times on the podcast, but I haven't actually done a proper podcast on it.
So, well, I guess for the listeners, the replication crisis is that many phenomena, especially in the field of social psychology, in that sub-discipline, have turned out not to be replicated.
That is, other scientists come in, and especially if the findings are counterintuitive or appear astonishing or that our intuitions wouldn't lead us to expect those.
Many of those have not been replicated, and so people are going back to the drawing board.
But I think, as it pertains to my work and the work that I talk about in When Men Behave Badly, I'm not at all worried about it, because these sex differences, they are large in magnitude and highly replicable.
And it's one of the reasons why, you know, from early on, why I started studying 37 cultures rather than just, you know, a couple of samples from North America or Western Europe, because, you know, you don't want to stake your career on findings that are not replicable.
And so I always try to instill that in my graduate students, that you want to be You want to be sure yourself that the findings are solid and replicable before you publish them so that you don't fall into that trap.
And so I can tell you with respect to some of the sex differences in mate preferences that I've documented and that others have attempted to replicate, and in sexual jealousy as another example, even people who dislike the theoretical lens that I use are still able to replicate the actual results in their own labs.
And so, I feel very confident in this case.
I think, in fact, these sex differences are among the most replicable in the field of psychology.
So, okay.
So, let's start.
Let's take it from the top or the bottom, as the case may be.
How do we define sex biologically?
Biologists define sex Very simply, by the size of the sex cells, so the gametes, that is, the males are defined as the small ones.
In the human case, you have basically sperm, which are, you know, little more than tiny packets of DNA and, you know, an outboard motor, you know, adaptation designed to get to the the egg to fertilize it.
Females are defined as the ones with the larger sex cells, in the human case, the egg, which is large, many times the size of sperm, and filled with nutrients.
And so from the moment of conception, and then subsequently, females are investing more than males.
It's So some people use this kind of a cliché at this point, but sperm are cheap, eggs are expensive, but it is true.
And so Sex, defined in that way, is different from things like gender identity or sexual orientation or sexual attraction.
And so, for biologists, it's very clear, you know, that sex evolved somewhere around 1.3 billion years ago from asexually reproducing species.
So it's been going on a long time, but there are two sexes.
And I think there's been also a lot of confusion that has developed when people intermingle that biological definition of male and female with all these other phenomena such as identities and orientations and labels.
And how old is sexual reproduction?
Estimates vary, but it's somewhere between 1 billion and 2 billion years ago is when it first evolved.
So it's been going on for, I guess, you know, you'd say a quarter or a third of the time of life on Earth.
I think life on Earth evolved about three and a half billion years ago.
So sexual reproduction, it took at least a billion or two billion years for sexual reproduction to evolve after that.
Yeah, so we've been at this for a long time, and even in our hominid form, we've been at it for a long time.
And that's worth remembering as we get into the details here, because when you describe the different mating strategies and their evolutionary logic, If you lose sight of the vast amount of time wherein incremental changes could have tuned us differently, it can seem less plausible than it otherwise would.
I mean, this is just... we have bad intuitions for how much time it need take for things to change in evolutionary terms, and we certainly have bad intuitions for how long tens and hundreds of thousands of years really is.
Yeah, no, exactly.
I mean, in a way, it's our evolved psychology that causes those failures of intuition because we evolved to solve problems in, you know, the here and now and in time spans of seconds or minutes or sometimes days and occasionally years, but we didn't evolve to even understand deep time or the concept of a billion years.
It's very difficult to make that transition, and some scientists have used analogies or metaphors to try to make that leap.
So, for example, a football field.
If evolution of life started at one end of a football field and then evolved to the point of modern humans, Sort of where are we in that space?
And you get down to, I don't remember the exact details, but something like the last inch of the football field where our species evolved a couple million years ago.
And then when you talk about even things like farming and technology, the agricultural revolution, and you're down to seconds at that point.
But sometimes those devices can help people make the leap to try to tune their intuitions to deep time.
So, what do we think we understand about the differences between men and women with respect to evolved mating strategies?
Well, I guess we can start maybe just with a few basics, and that is, we've mentioned sperm and egg, but males and females, in the human case, we have dramatically different reproductive anatomy and physiology.
And consequently, these have posed different adaptive problems for males and females.
So, for example, fertilization occurs internally within the female body, not within the male body.
What this creates is an asymmetry in certainty of parenthood, where women are always 100% certain that they are the mothers.
No mother ever gave birth, as far as I'm aware, and as the child is emerging from her body, wondered, gee, is this kid really my own?
Mothers are 100% certain.
Men can never be sure.
So some cultures use the phrase, uh, mama's baby, papa's maybe, to kind of capture that asymmetry.
But this stems from the fact that fertilization occurs internally within women, not within men.
And so this is an example of an adaptive problem that men have faced recurrently over evolutionary time that no woman has ever faced.
And so, you take this example, other examples, other fundamental features are the obligatory parental investment that each sex has to devote to produce a single child.
Women have that obligatory nine-month investment, and it's obligatory in the sense that women don't have a choice about it, really.
I guess, well, maybe some modern technology, I mean, you can farm it out to other female bodies, but A woman can't say, look, I'm very busy with my career right now.
I really only want to put in two and a half months of the pregnancy.
It's obligatory, and nine months is heavy investment metabolically.
It also creates problems for women because her center of gravity is moved forward, and so it puts extra torque on her back.
And that's one reason why we think that male and female spines are differently constructed, where females have a wedge-like vertebra in there, which helps to relieve the torque when that center of gravity is moved forward.
But to produce that single child that takes a woman nine months, it takes a man just one act of sex at a minimum.
Now, of course, men do more than the minimum typically, or often they do, although their investment varies a lot.
But so you take this stark sex difference in this asymmetry in obligatory parental investment, just to produce the child to start with, and then that creates different adaptive problems for men and women, and also a different payoff matrix when it comes to optimal mating strategies.
That is, for example, and this is one of the ones that I think creates the most havoc that I talk about in the book, is that males, their primary limit historically over evolutionary time on reproductive success has been the number of fertile women that they can successfully inseminate for women.
And so adding additional sex partners historically has led to increases in reproductive success for men.
For women, adding additional sex partners does not.
Now, women can sometimes benefit from additional sex partners, as I talk about in the book, under why women have affairs, which I think is a really interesting dimension of a hidden side of female sexual psychology.
But you can see that due to the asymmetries in investment, there are going to be sex differences in optimal mating strategies.
And so the key point that I want to make here is that is that it would be astonishing to an evolutionist if you found profound sex differences in our reproductive anatomy and physiology and zero attending psychological, behavioral, and strategic sex differences that correspond to the adaptive, the different adaptive problems that those sex differences in anatomy and physiology create.
And so we look, and there are clear predictions in some cases, and we find that yes, lo and behold, they do.
You do find psychological and strategic and behavioral sex differences in precisely the domains where the sexes have faced these different adaptive problems.
And one of the things I'll just mention, some people say, oh, you're saying men are from Mars and women are from Venus, which I absolutely hate, because no, that's not what we're saying.
The meta-theory of evolutionary psychology predicts both sex differences and similarities between the sexes at the psychological level.
And it's a very precise meta-theory.
Namely, we expect similarities between men and women in all domains in which they face approximately similar adaptive problems.
So, as an example, both sexes have faced the problem of eating, you know, getting fuel for the machine.
And so, men and women have, by and large, similar, although not identical, taste preferences.
You know, for things like sugar, fat, salt, and protein.
Okay, where do you see sex differences in taste preferences?
Well, when women get pregnant, and they face an adaptive problem that men don't face, which is namely that substances that are teratogenic, meaning dangerous to the fetus, in minute quantities are perfectly fine for an adult woman, but if they pass the placental barrier, They can damage the fetus.
And so, all of a sudden, women's taste preferences change when they get pregnant.
But that example illustrates that we expect sex similarities in large areas, perhaps most areas of psychology.
Now, as it happens, where do we expect sex differences?
Well, they fall very heavily in the mating and sexuality domains.
Yeah, that's a very interesting and useful frame to put around this.
If you just start with the acknowledgement that evolution is a thing, and that the two sexes have different anatomies and physiologies related to reproduction, and different resource demands and constraints, and fairly discrepant interests
In genetic terms, with respect to mating options, extracurricular mating options, infidelity, just how it advantages the propagation of the man's genes to have sex outside of marriage versus the woman's.
It would be a miracle and, you know, even a strike against the theory of evolution if there were no differences there in evolved psychology.
Yes.
Yeah, indeed.
And it would be, I mean, it would be like saying humans have developed the anatomy and musculature for bipedal locomotion, but we don't have bipedal locomotion, the behavior.
Yeah, so let's get into some of these details.
Maybe we could just take specific concepts here and extrapolate from them.
So you have a married couple that is They have shared interests.
Again, I'm not talking about the psychological first-person interests.
We're talking about the gene's eye view of things.
They have shared genetic interests in successfully raising children, but how are their interests not precisely aligned, in your view?
Yeah, it's a great point.
And men and women do cooperate, and cooperate supremely and over long periods of time for that precise reason.
That is, they have a shared vehicle, a shared genetic vehicle, that's carrying the precious cargo into the future.
But they differ In very predictable way so so one is if there is a possibility for infidelity okay and this could be sexual infidelity where sexual or reproductive resources are being diverted to someone outside of the couple.
Or even financial infidelity, when one partner is shunting financial resources toward either their interests or even toward their kin at the expense of their partner's interests or their partner's kin.
You have the possibility of a dissolution or divorce or breakups, where And that possibility creates a potential for conflict.
So I outline, I think in the book, something like 12 ways in which men and women's interests from an evolutionary perspective can depart from one another.
So even in the case I end with that, ideally, For minimizing conflict, men and women would, the couple would die at exactly the same time.
Because if one member of the couple dies and the other does not, then the one who is still alive can remate, and then in some cases reproduce and have additional children.
And so the pooled resources can be devoted toward interests that are not, you know, aligned with the interests of the original partner.
So there's a very predictable set of circumstances in which the interests of men and women depart from an evolutionary perspective with the qualification that that also occurs within the context of shared interests.
Okay, so from the genetic perspective here, it's very easy to explain the man's infidelity or inclination to be unfaithful, provided he can get away with it, right?
There's really no limit to the Evolutionary advantage for him.
If he could impregnate a thousand women surreptitiously and actually expend no resources on them and their progeny, that would be an amazing gain for him in evolutionary terms over remaining faithful to his wife.
And one could also add that, again, this is an all-too-common inclination for men, but we could also say that he should be highly incentivized to donate sperm to a sperm bank whenever he can.
I mean, that's really the ultimate case where he could father scores of children for whom he would shoulder no financial or emotional responsibility.
And from his genes perspective that would all be to the good, but there are very few men who feel any internal psychological motivation to do such a thing.
So there's clearly daylight between what people feel they want to do and what would make genetic sense if you were going to use the cold logic of evolution.
But of course we haven't evolved in the presence of sperm banks and we don't have intuitions for how good it would be to Father to hundreds of children we never meet, but there's something more mysterious, or at least slightly harder to explain, about a woman's tendency to be unfaithful in a marriage.
What do we know about the evolutionary logic of that?
Yeah, it's a great question, and I devote a chunk of my book to exploring that very issue.
Just one quick comment on the sperm bank.
I think you hit the nail on the head with it, that sperm banks are evolutionarily novel, and we don't have adaptations to things that are evolutionarily novel.
And so that's not really a great mystery.
As Steve Pinker once said, his genes, he's never reproduced, he says his genes can go jump in a lake.
We're just operating from our evolved psychology that evolved not to these weird modern conditions that we find ourselves in.
Anyway, so your question about female infidelity, I think it's really fascinating because this is an area where I end up disagreeing with some of my evolutionary psychology colleagues, even those who I have a lot of respect for, such as Marty Hazelton, a former student of mine, Steve Gangestad, and others.
Where the traditional explanation which i originally thought was compelling is that.
Is that women can in at least in some cases get high quality jeans from an affair partner while retaining the investment.
of resources and commitment and fathering from a stable, regular mate.
And in principle, that logic could work out.
So, in particular, if a woman is mated to a man who has inferior genetic material, for example, genes for diseases or ill health or a compromised immune system, in principle, that can work out.
And there have been a variety of tests of that, and this is still under contention, but if you ask the question, well, why do women have affairs?
Do women really have affairs for the functional reason of obtaining good genes from these affair partners?
And what I argue is for a different hypothesis that I call the mate-switching hypothesis.
That is, women have affairs primarily when they're unhappy with their current relationship.
And you may say, well, boy, that is the least surprising thing I've ever heard.
But it's interesting that if you look at men who have affairs and compare them with men who don't have affairs, there's no difference in their marital happiness or relationship satisfaction.
So women have affairs when they're unhappy with the relationship.
The nature of their affairs differs qualitatively on average, and we're talking about on average differences here, in that something like 70% of women become Deeply emotionally involved with or in love with their affair partner and so that that is that would be a terrible design feature if all you're trying to do is obtain the good genes and you don't want to be falling in love with the affair partner if that were the if the good genes explanation were correct.
Right.
If you look at what motivates men to have affairs, desire for sexual variety, novelty, novel sexual experiences, is overwhelmingly the motivation.
Not exclusively, but there's this enormous sex difference in the design of male affairs and female affairs.
And males typically Don't fall in love with their affair partners, although of course some do, and in fact try to adopt strategies to minimize the costs, the risks, and investment in the affair partner.
And so, my argument stems from the notion that something could always go wrong in a relationship.
So, going back over human evolutionary time, a man could get injured in a war or get killed.
And bad stuff can befall any relationship.
The woman could get dumped or he might decide he wants to take on a second or third wife, compromising the investment he's devoting to the first wife.
And so something can always go wrong.
And so my argument is that if a woman would have been left totally unprepared and had to just suddenly, if her husband got killed or dumped her, she would have to reenter the mating pool.
That wouldn't be optimal because women take out what I call maid insurance.
That is, we have house insurance and car insurance if something bad should happen to our house or car.
We hope that it doesn't, but it's a backup, and that women do exactly the same thing.
They cultivate backup potential mates and sometimes have an affair in order to exit from a bad or cost-inflicting relationship, or to trade up in the mating market if she can obtain a substantially better quality mate than the one that she has, or as a transition back into the mating pool.
So I argue, and again this is in contrast to some of my evolutionary psychology colleagues, I think it provides a more comprehensive explanation for why women have affairs, and the evidence for the good genes or dual mating strategy hypothesis, the way it's sometimes called, the evidence is turning out to be a lot shakier than originally thought.
So, there's something there, but it doesn't seem to explain the majority of cases where women have affairs.
I guess they could both be true, but the emotional entanglement that many women feel when having an affair could be a byproduct of just the degree to which they weight emotional engagement and the prospect of Finding a caring mate more than men do in any mating circumstance.
I guess there's this background fact that we haven't spelled out yet, which is that men and women tend to value different things in mates, or the same things to very different degrees.
By comparison, the cartoon version of sex differences sort of applies.
Again, there's going to be a bell curve over both populations, and there will be women who are psychologically more like men than most women, and there'll be men who are more like women than most men, so that these distributions will overlap considerably.
But Generally speaking, men tend to be more concerned about how women look than women are with respect to male appearance, and presumably the evolutionary logic there is on the physical, you know, criteria of bearing children and being healthy all the while.
And women care more about social status and the prospects that the man will be a good source of, you know, care and resources And that discrepancy certainly explains a lot of what we see out in the world.
But to your last point, if the operating systems are that different with respect to those variables, I guess emotional entanglement under the conditions of infidelity, if you're a woman, could just be a kind of Cost of the underlying mating strategy logic as opposed to something that proves that you're not actually out to surreptitiously get good genes, you know, behind your partner's back.
Yeah, well, I think that, I mean, you have to look at, with all these cases, the weight of the evidence, and I think there has been enough time for evolution by selection to decouple that emotional involvement for women under certain circumstances.
So, as I mentioned, it's a terrible design feature, terrible psychological flaw, if the sole goal is getting good genes.
But it's an excellent design feature if the goal is a mate-switching goal.
I seem to remember there being research around women's mate preferences changing to one or another degree when they're ovulating.
Did I make that up, or is that?
Yes, no, no, no, you didn't make that up.
There's been a fair amount of research on precisely that, and that was the body of research that was used to try to test the good genes hypothesis, or the dual mating strategy hypothesis, The problem that it runs into is a couple things.
One is, well, what qualifies as markers of good genes?
And the people who have argued for the good genes hypothesis basically selected things like Masculinity and symmetry.
Those were the two that were primarily focused on so that women were hypothesized to prefer more masculine and more symmetrical men around ovulation when they're most likely to conceive.
But the question is like, why would these two be viewed as the exclusive markers of good genes?
So another example is, I mean, one of the most heritable things that we know, and I know you've talked about this on another podcast, but is intelligence.
Intelligence is at least moderately heritable, and probably a bit more than moderately heritable, and we know that intelligence is beneficial for solving a wide variety of problems, but women's preferences for intelligence does not shift at ovulation.
Okay, so there's the conceptual issue of what qualifies as markers of good genes... I have a knee-jerk response to that.
What we mean by intelligence now is quite a bit more nuanced than what counted as an evolutionarily important difference in intelligence, you know, even a few hundred years ago, much less 75,000 years ago, right?
If all you're doing is clubbing one another over the head with rocks, being smart while you're doing that didn't give much of a differential advantage.
Hedge fund managers and software engineers and other markers of differential success now are a bit like sperm banks, right?
We just did not evolve to pay attention to those differences.
Yeah, yeah, possibly.
I mean, I accept your point, I guess, partially.
Where I would push back a little on it is that, you know, we didn't just, our ancestors didn't just hit each other over the head with rocks.
They had to socially, they had to navigate social space too, yeah.
Navigate social space and even, you know, the physical environment, you know, create, navigate to habitats that had resources.
But yeah, the social intelligence hypothesis is one hypothesis for the evolution of high levels of human intelligence.
So I would push back a little bit on that, and I think it's an open question.
I mean, if you go to, I don't know, traditional hunter-gatherer societies, do the people that they call intelligent, would they be the same people that we call intelligent?
But I, of course, recognize that your point about, you know, we have very specialized, you know, skills and abilities in mathematics and hedge fund managing and so forth that wouldn't have been relevant ancestrally.
But I want to get back to the second problem that I see, and it actually relates to the issue you brought up very early in our conversation, which is the replicability crisis.
So, it's very difficult and time-consuming to do this ovulation research.
You know, you really have to track women over time and over a number of cycles to really document it well.
And the attempts, so there have been several large-scale attempts to replicate these ovulatory shifts in mate preferences and that have failed to find the effects.
And so the effects are either a lot less replicable than initially thought or they're a lot weaker than initially thought and require much more sensitive designs to detect And so I think that there are, you know, both conceptual problems with the good genes hypothesis, as well as empirical problems.
Okay, so we're back to the man and the woman, however hapless they might be.
Let's say they have one child, and Tolstoy got here first, and there are happy families and unhappy ones, and the happy ones are all alike, and the unhappy ones are unhappy in their own way.
But, how do the predictable variants of unhappiness here conform to the different mating strategies, right?
So, I mean, just take the response to infidelity, let's say that, or just imagined infidelity.
You ask the wife to imagine, you know, her husband cheating on her, and vice versa.
What do each party find most disturbing about that consciously and how does that relate to their different mating strategies biologically?
Yes, well, there I think were two questions embedded in your question.
One is, what are the sources of unhappiness in couples?
And then the second is, what are the sex differences in the nature of jealousy and infidelity?
And basically there are, and these are highly replicable.
And one is, A real cool study on verbal interrogations when people discover that their partner is cheating or might be cheating.
And men want to know, did you have sex with him?
And women want to know, do you love her?
And so this sex difference, when you imagine your partner being unfaithful, we've done studies where we ask, let's say your partner got emotionally involved with an affair partner and had sex with them, had passionate sexual intercourse, which aspect of the infidelity would bother you more?
And women are much more likely to say that the emotional aspects, the falling in love, the attachment, that those aspects bother women a lot more than men, whereas it's the sexual aspects That bother men a lot more.
And so there's, you know, not that women are overjoyed about finding their partner having sex.
They're not.
They're upset about it, but not as of course they should be.
It can't make sense.
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