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Welcome to the Huberman Lab podcast, where we discuss science and science based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. My guest today is Doctor David Buss. Doctor Buss is a professor of psychology at the University of Texas, Austin, and he is one of the founding members and luminaries in the field of evolutionary psychology. Doctor Buss laboratory is responsible for understanding the strategies that humans use to select mates in the short and long term, and he is an expert in sex differences in mating strategy. His laboratory has explored, for instance, why women cheat on their spouses or their long term partners, as well as why men tend to cheat on their spouses and long term partners. Hes also explored a number of things related to the courtship dance that we call dating and securing a mate, including the use of deception related to proclamations of love or promises of finances or sexual activity. Doctor Buss laboratory has also evaluated how status is assessed, meaning how we evaluate our own worth and our potential as a mate, and who is, let's just say, within range of a potential mate, both in the short and long term. For instance, today we talk about how people don't just make direct assessments of their own and other people's value as a potential mate, but also using the assessments of others to indirectly determine whether or not they stand a chance or not in securing somebody as a short or long term mate. His laboratory has also focused on some of the complicated and varied emotions related to mating love in relationships such as lust and jealousy, and he's extensively explored something called mate poaching, or the various strategies that men and women use to make sure that the person that they want to be with or the person they are with is not with anyone else or seeking anyone else, and indeed that other people don't seek their mate. Doctor buss work also relates to how biological influences, such as ovulation or time within the menstrual cycle, influences mate selection or tendency to have sex or not with a potential short or long term mate. And more recent work from doctor Buss Laboratory focuses on the darker aspects of mating and sexual behavior in humans, including stalking and sexual violence. Today, we discuss all those topics. We also discuss some of the strategies that humans can use to make healthy mate selection choices and for those that are already in committed relationships, to ensure healthy progression of those committed relationships. In addition to publishing dozens of landmark scientific studies, doctor Buss has authored many important books. A few of those include the evolution of desire and why women have sex, and his most recent book is the one that I'm reading now, which is called when men behave badly, the hidden roots of sexual deception, harassment, and assault. And it's an absolutely fascinating read. It has endorsements from doctor Robert Sapolsky, professor at Stanford, who's been on this podcast as a guest before, as well as Steven Pinker and Jonathan Haidt, who wrote the coddling of the american mind. It's a really important book, I believe, and one that doesn't just get into the darker aspects of human mating behavior and violence, but also strategies that people can take to ensure healthy mating behavior and relationships. There's so much rumor, speculation, and outright fabrication of ideas about why humans select particular mates in the short and long term, what men and women do differently, and so on. What I love about doctor Buss work is that it's grounded in laboratory studies that are highly quantitative, using rigorous statistics. And so throughout today's discussion, you'll notice that I'm wrapped with attention trying to extract as much information as I can from doctor Buss about the real science of human mate selection and mating strategy. I'm certain that everyone will take away extremely valuable knowledge that they can use in existing or future relationships from this discussion with Doctor Buss. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is Athletic Greens. Athletic Greens is an all in one vitamin mineral probiotic drink. I've been taking athletic greens since 2012, so I'm delighted that they're sponsoring the podcast. The reason I started taking athletic greens, and the reason I still take athletic greens once or twice a day, is that it helps me cover all of my basic nutritional needs. It makes up for any deficiencies that I might have. In addition, it has probiotics, which are vital for microbiome health. I've done a couple of episodes now on the so called gut microbiome and the ways in which the microbiome interacts with your immune system, with your brain to regulate mood, and essentially with every biological system relevant to health throughout your brain and body. With athletic greens, I get the vitamins I need, the minerals I need, and the probiotics to support my microbiome. If you'd like to try athletic greens, you can go to athleticgreens.com huberman and claim a special offer. They'll give you five free travel packs plus a year's supply of vitamin D three k, too. There are a ton of data now showing that vitamin D three is essential for various aspects of our brain and body health. Even if we're getting a lot of sunshine, many of us are still deficient in vitamin D three, and k two is also important because it regulates things like cardiovascular function, calcium in the body, and so on. Again, go to athleticgreens.com Huberman to claim the special offer of the five free travel packs and the year supply of vitamin D three k two. Today's episode is also brought to us by element. Element is an electrolyte drink that has everything you need and nothing you don't. That means the exact ratios of electrolytes are an element, and those are sodium, magnesium and potassium. But it has no sugar. I've talked many times before on this podcast about the key role of hydration and electrolytes for nerve cell function, neuron function, as well as the function of all the cells and all the tissues and organ systems of the body. If we have sodium, magnesium and potassium present in the proper ratios, all of those cells function properly and all our bodily systems can be optimized. If the electrolytes are not present and if hydration is low, we simply can't think as well as we would otherwise. Our mood is off, hormone systems go off, our ability to get into physical action, to engage in endurance and strength and all sorts of other things is diminished. So with element, you can make sure that you're staying on top of your hydration and that you're getting the proper ratios of electrolytes. If you'd like to try element, you can go to drink element. That's lmnt.com huberman and you'll get a free element sample pack with your purchase. They're all delicious. So again, if you want to try elemt, you can go to elementlmnt.com Huberman Today's episode is also brought to us by waking up. Waking up is a meditation app that includes hundreds of meditation programs, mindfulness trainings, yoga, Nidra sessions, and NSDR non sleep deep rest protocols. I started using the waking up app a few years ago because even though I've been doing regular meditation since my teens and I started doing yoga Nidra about a decade ago, my dad mentioned to me that he had found an app turned out to be the waking up app, which could teach you meditations of different durations, and that had a lot of different types of meditations to place the brain and body into different states, and that he liked it very much. So I gave the waking up app a try and I too found it to be extremely useful because sometimes I only have a few minutes to meditate, other times I have longer to meditate. And indeed, I love the fact that I can explore different types of meditation to bring about different levels of understanding about consciousness, but also to place my brain and body into lots of different kinds of states, depending on which meditation I do. I also love that the waking up app has lots of different types of yoga nidra sessions. For those of you who don't know, yoga Nidra is a process of lying very still but keeping an active mind. It's very different than most meditations. And there's excellent scientific data to show that yoga nidra and something similar to it called non sleep, deep rest, or NSDR, can greatly restore levels of cognitive and physical energy, even with just a short ten minute session. If you'd like to try the waking up app, you can go to wakingup.com huberman and access a free 30 day trial. Again, that's wakingup.com huberman to access a free 30 day trial. And now my conversation with Doctor David Buss. Well, David, delighted to be here. I've followed your work for a number of years and I'm excited to ask you a number of questions about these super interesting topics about how people select mates, how they lie, cheat, but also behave well in this dance that we call mate choice.
B
Yes. Yeah. Fortunately, there are well behaving humans in the mix here.
A
Good to know. Just to start off, perhaps you could just orient us a little bit about mate choice. Some of the primary criteria that studies show men and women use in order to select mates. Both, shall we call them transient mates as well as lifetime mates.
B
Right. Well, that's a critical distinction, because what people look for in a long term committed mateship, like a marriage partner or a long term romantic relationship, is different from what people look for in a hookup or casual sex, or one night stand, or even a brief affair. So that's actually critical. I wonder if we could maybe just back up a second and just talk a little bit about the theoretical framework for understanding mate choice. So it basically stems from Darwin's theory of sexual selection. And most people, when they think about evolution, they think about cliches like survival of the fittest or nature red in tooth and claw. And Darwin noticed that there were phenomena that couldn't be explained by the so called survival selection. Things like the brilliant plumage of peacocks. Sex differences like in, you know, stags, for example, have these massive antlers and the females of the species do not. And so he came up with the theory of sexual selection, which deals not with the evolution of characteristics due to their survival advantageous, but rather due to their mating advantage. And he identified two causal processes by which mating advantage could occur. One is intrasexual competition with the stereotyping. Two stags locking horns in combat with the victor, gaining sexual access to the female loser, ambling off with a broken antler and dejected and low self esteem and needing psychotherapy, perhaps, or mate. I mate value improvement therapy. And the logic was, whatever qualities led to success in these same sex battles, those qualities get passed on in greater numbers. And so you see evolution, which is change over time and increase in frequency of the characteristics associated with winning these, what Darwin called contest competition. Now, we know that the logic of that is more general now and involves things like in our species competing for position and status hierarchies. So anyway, so intrasexual competition is one. But the second most relevant to your question about mate choice is preferential mate choice. That was the second causal pathway. And the logic there is that if members of one sex agree with one another, if there's some consensus about the qualities that are desired, then those of the opposite sex who possess the desired qualities or embody those desired qualities, they have a mating advantage, they get chosen, they get preferred. Those lacking desired qualities get banished, shunned, ignored, or in the modern environment, become incels. And so the logic there is very simple, but also very powerful. And that is that whatever qualities are desired, consensually desired, if there's some heritable basis to those, then those increase in frequency over time. And in the human case, these two causal processes of sexual selection are related to each other in that the preferences of the mate preferences of one sex basically set the ground rules for competition in the opposite sex. So if, for example, hypothetically, women preferred to mate with men who were able and willing to devote resources to them, then that would create competition among men to claw their way and beat out other men in resource acquisition and then displaying their willingness to commit that to a particular woman. And same with women, though, one of the interesting things about humans is that we have mutual mate choice, which is not true in all species. And that is that it's not just a matter of, you know, you selecting someone to be your mate, they have to reciprocally select you. And so with mutual mate choice, we have both preferences, mate preferences that women have and mate preferences that men have. And consequently, competition among men for access to the most desirable women. In competition among women for access to the most desirable men. So that's sort of a little bit of theoretical backdrop. So you asked, well, what are the qualities that men and women desire? And maybe we'll start with long term mating and then shift to short term mating. And long term mating is interesting in and of itself in that it's very rare in the mammalian world. So there are more than 5000 species of primates of which, I'm sorry, more than 5000 species of mammals, of which we are one. But the percentage of mammals that have anything resembling, like a pair bonded long term mating strategy, it's about three to 5%. It's extremely rare. And even our closest primate relatives, the chimpanzees, they don't have a long term mating strategy. They don't have anything resembling pair bonded mating in the chimps. The females come into estrus. Almost all the sexual activity occurs during the estrus phase. After that, males and females basically ignore each other for the most part, with some exceptions. But with humans, you have the evolution of long term pair bonding attachment heavy male investment in offspring, relatively concealed ovulation. And so these are kind of unique aspects of the human mating system. So to get to your question so, well, what are the qualities? So the best, the most large scale study that's been done on this is a study that I did a while back of 37 different cultures and it's now been replicated by other researchers. But basically what we found is three clusters of things. We found qualities that both men and women wanted in a long term mate. We found some qualities that were sex differentiated where women preferred them more than men or men preferred them more than women. Then we found some attributes that were highly variable across cultures in whether people found these as desirable or indispensable or irrelevant in a mate. And so I could give examples of each of these, if that.
A
Yeah, that would be great. I'd love to know what some of the common themes were across these cultures in terms of what's being mate and sexually selected for.
B
Yeah. So, so some of the things that were. So if you talk about universal desires, the things that men and women share, they're things like intelligence, kindness, mutual attraction and love, which is really kind of heartwarming because some people think that love is a recent western invention by some european poets. But it turns out it's not true. You go to the Kung San and Botswana and they describe pretty much the same experience as a falling in love as we do. And even describe the distinction between this kind of infatuation stage of love and the attachment phase, where you can't maintain this frenzy of infatuation and obsession for very long, six weeks, maybe six months at most. Otherwise you can get nothing else done in your life.
A
Those are those dopamine circuits firing at high frequency. Yes.
B
Yeah. So mutual attraction, love, good health, dependability, emotional stability, although there's a bit of a sex difference there with women preferring it a bit more than men. And so basically, and these may seem obvious, so no one wants a stupid, mean, ugly, disease ridden mate. And so perhaps obvious, but no one knew this in advance of the 37 culture study. So these were some universal preferences. So you go to the Zulu tribe in South Africa, or, you know, Rio de Janeiro in Brazil or Portugal or Oslo or anywhere in the world, and these are qualities that people universally desire in long term mates. Sex differences. So sex differences basically fell into two clusters. So women, more than men prioritized good earning capacity, slightly older age, and the qualities associated with resource acquisition. So these are things like a man's social status. Does he have drive? Is he ambitious? Does he have a good long term resource? Trajectory is one way that I like to phrase it, because women, often they don't look at necessarily the resources that a guy possesses at this moment. But what is his trajectory, may I ask?
A
Just sorry to interrupt, but may I ask, is there anything known about the commonalities of how that is assessed? You know, is it, you know, he's rolling out of bed early and running 8 miles, he's showing proficiency in school, he handles himself well socially at parties, isn't drinking too much, but knows when, you know. I mean, obviously they're integrating multiple cues. The brain is a complex place, but is there any information about what those variables are across cultures?
B
Yeah, well, I think that there's been less attention to that. So that's a great question. One of the things that we do know across cultures is that women attend to the attention structure. So the attention structure is a key determinant of status. So the people who are high in status are those to whom the most people pay the most attention.
A
So the attention of others to them, not how well a given potential mate can focus and pay attention, necessarily.
B
Yes, exactly. But women, look, I mean, is the guy, even in the modern environment, is the guy spending 8 hours a day playing video games, eating cheetos and drinking beer? Or is he devoting effort to his professional development? So hard work, ambition, does he have clear goals, or is hedgest in an existential crisis not knowing what he's going to do with his life? So those are some of the qualities that people look for. And also, women use what's called in the literature, mate choice copying. And this is related in part to the attention structure, that is guys who have passed the filters of multiple women. Those are like pre approved men. So we've done studies where you just take a guy, photograph him alone, versus take the same guy, put an attractive woman next to him, or put two women next to him, and women judge exactly the same guy to be much more attractive if he's paired with women than if he's not. And some guys exploit this in the modern world by hiring wing women to go with them on dates and so forth. My sister, a former girlfriend or whatever, so. But you're correct in that women use multiple cues to assess these things, and they change over time. So in the modern environment, even things like the attention structure, does this guy have a million Twitter followers or I three Twitter followers. So that is an index of the attention structure and hence the status of the guy within the broader community. And from an evolutionary perspective, it's reasonable that women would prioritize these qualities because of the tremendous asymmetry in our reproductive biology, namely that fertilization occurs internally within women, not within men. Women bear the burdens of the nine month pregnancy, which is metabolically expensive, as well as creating opportunity costs in terms of mobility and solving other tasks that people need to solve in the course of their lives. And so, one way to phrase that is that the costs of making a bad mate choice are much heavier for women when it comes to sexual behavior, certainly because, and the benefits correspondingly of making a wise mate choice are higher for women in the sexual context. But as I said, we have mutual mate choice in our species. And so what do men value more than women? Physical attractiveness.
A
They rank that as a more important criteria than do women. About Mendez.
B
Yes, yeah, exactly.
A
Consistently.
B
Across culture, consistently. And it's not that women are indifferent to it. So women do pay attention to a guy's physical appearance, his fitness, and so forth. And guys are actually off base in thinking that women prefer more muscular men than they actually do. So, like in muscle magazines, these men with bulging biceps and so forth, women don't find that especially tragic, but they do prioritize, fit men, a good shoulder to hip ratio, and other qualities of physical appearance, as well as things like cues to health. So physical appearance provides a wealth of information about a person's health status, but also provides for men a wealth of information about a woman's fertility, her reproductive value. Now, not that men think about that consciously. I mean, men don't walk down the street and see a woman and say, oh, I find her attractive because I think she must be very fertile. Maybe a few weird people do that, but most men just. It's like they just find those cues attractive. And the cues are cues associated with youth and health, because we know that youth is a very powerful cue to fertility and reproductive value. So men prioritize physical appearance. And in the field of psychology, it used to what I was taught when I was an undergraduate, that you can't judge a book by its cover, that physical attractiveness was infinitely arbitrary, infinitely culturally variable, and it's simply not true. We know now, based on the last 20 years of scientific studies, that the cues that men find attractive women are not at all arbitrary. There is some variation across cultures, like in relative plumpness versus thinness, but things like clear skin, clear eyes, symmetrical features, a low waist to hip ratio, full lips, lustrous hair, all these are qualities that are associated with youth and health, and hence have evolved to be part of our standards of attractiveness. And so it's not just that men are these superficial creatures who evaluate women on the basis of appearance. There's an underlying logic to why they do so. And as I said, relative youth. This age thing is one of the largest sex differences you find in long term age selection, with women preferring somewhat older men and men preferring somewhat younger women.
A
Is there a consistent age gap to relate to that statement?
B
Yes, there is. Age gap, though, depends on the age of the man. So we can document this. So in my studies, what we found is that men preferred women who were about three to four years younger than they were on average. And I'll qualify this in a second. Women preferred guys who are about three and a half to four and a half years older than they were. So there was a sex difference going in the opposite direction. But as men get older, they prefer women who are increasingly younger than they are. So one way to gauge this, so there are actual marriage statistics, and then there are express preferences, and both sexes kind of converge. So if you look at first marriage, second marriage, third marriage, if people get divorced and remarried, average age gap is, in America anyway, is three years at first marriage with the guys being older, five years at second marriage, and eight years at third marriage. So that is, as men are getting older and getting divorced and remarrying, they are marrying women who are increasingly younger than they are in terms of preferences. It's also expressed in preferences so it doesn't go down. So like say a 25 year old man would say prefer a woman who's 20 or in her early twenties. 35 year old man might prefer a woman who's in her late twenties or early thirties. 50 year old man might prefer a woman who's say 35 to 38. So the preferences do go up but the gap gets increasingly larger. And the reason that you don't see things like why aren't men preferring women? So peak fertility in humans is around age 24. And so you say well why aren't the 60 year old men prioritizing 25 year old women? Well as I mentioned, we have a, it's a reciprocal mutual mate choice phenomenon.
A
She constrains the equation too.
B
Well she constrains it. But also marriage and long term mating are things other than reproductive unions in the modern environment. That is their, you know, you're supposed to do things as a couple. And if you get too large an age gap then essentially you're in different cultures, you grow up with different songs, and if the cultural gap gets too large you don't understand each other. So there are constraints on that. But if you look at contexts where there are no constraints of that sort, historically kings, emperors, despots, et cetera, and I'll give one more modern example. They basically prefer young, fertile, attractive females. And if they have harems, they stock the harems with those and then circulate them out when they're 30 and so forth. So if you look at marriage systems that are unconstrained, then the preferences are more likely to be revealed or within cultures, that is, if you look at men who are in a position to get what they want. So as Mick Jagger noted, you can't always get what you want, but if you try, sometimes you get what you need.
A
I hear that most of the time he got what he needed, right?
B
Right? He got what he wanted, right? Yeah, and maybe what he needed. But he was in a position, I don't know if he still is, he's in his seventies now, but he was in a position as was, let's say Rod Stewart to take another example, or Leonardo DiCaprio. If you were a male who's in a position where there are thousands of women potentially available to you and you can have your pick, then you see that clearer expression for younger females. There was a chart that was floating around the Internet of the girlfriends of Leonardo DiCaprio as he got older. So he's getting older and older and the graph of the age of his girlfriends, it basically stayed the same. It was in the early twenties or so.
A
He values consistency.
B
He values consistency. So anyway, the data converge on that. So these are universal sex differences in long term mate selection. Now, when we shift to. Oh, and I should mention cultural variability, because that's a critical thing, because there is. In my 37 culture study, what I found was the preference for virginity, that is, no prior sexual experience. That was the most variable desire across cultures. So you had cultures, like, at the time of the study, China. It was basically indispensable that a partner be a virgin. And then at the other end, you have Sweden, where Swedes typically place close to zero value on it. And some even find it undesirable, like, you're weird if you're a virgin. And so you have this whole spectrum.
A
This is virginity in the female, or is this also. This is not in China. Was it preference that the male and the female be virginity? It's a mutual mate selection?
B
Yeah, it was a preference for both sexes. Interesting. But it's a good question, because where there was a sex difference, it was always in the direction of males preferring virginity more than females. And we've gone back to China. So I still do research in China, among other places, and we've gone back and retested modern urban populations. And the importance of virginity has gone down in China, especially in the urban areas. And the sex difference that didn't exist before has now emerged where males value it more than females. And I think part of it was in previous times, you hit ceiling effects, where both sexes say, yeah, it's absolutely important to be a virgin. So there's cultural variation and cultural change over time in some of these qualities. But the sex differences that I described have remained invariant over the years. So since my 37 culture study, this has been replicated in at least a couple dozen different cultures. And we've gone back to some of the cultures. So I mentioned we've gone back to China, Brazil and India to look at cultural changes over time. And there have been, in some cases, dramatic cultural changes over time. But the sex differences that I described are invariant. They haven't changed a bit.
A
I be remiss if I didn't ask about truth telling and deception, because some of the measures that you're describing, age, for instance, one can potentially lie about. Right. I'm guessing that there are people who do that on online profiles and whatnot. From what I understand, people also lie about height and other features on online profiles, but some of them are much harder to hide.
B
Right.
A
Eventually the truth comes out about some, if not all of these things. So if you would, could you tell us about how men and women leverage deception versus truth telling and communicating some of the things around mate choice selection?
B
Yeah. Well, so basically, both men and women do deceive. So we have the modern cultural invention of online dating, which was little used ten years ago and virtually absent 20 years ago. And people do lie, but they lie in predictable ways. They lie in ways that attempt to embody the mate preferences of the person they're trying to attract. And so men do lie. They deceive about their income, their status, so they exaggerate their income by about 20%. They tack on about two inches to their height. So if they're 510, they round up to 6ft. So they don't like, if they're 510, they don't say that they're gigantic, but they kind of round it up in the more desirable direction. Women tend to deceive about weight, so they tend to shave about 15 pounds off of their reported weight. And both sexes post photos that are not truly representative of what they actually look like. So they might post photos of themselves when they were younger, or they're even advice tips on how to create the best selfie of the best angle that will maximally enhance what you look like.
A
Or just doctoring of photos, I'm guessing.
B
Oh, yeah, photoshopping, absolutely. And one of the things about it now you say, like, well, do people find out? Of course people do find out. I mean, I just give you one story about a colleague of mine who was doing, is a male who's doing Internet dating, and he picked only women who self describe as sevens on the one to seven on attractiveness. So the most attractive as self reported. And so went out with this one woman and she was missing her front teeth. And he said, well, call me picky, but missing her front teeth and she thinks she's like the top of attractive. He was a little disappointed about that. And women, of course, are disappointed. They meet a guy who they think is this physically fit, athletic guy, and he comes up, he's 300 pounds and overweighthouse. So people do find out. And so. And there are some Internet dating sites have kind of a vetting of the accuracy of something. So some things you can look up through public records. And does this guy have a criminal record? For example, is he on a sexual offender's website? So there's some things you can verify, but what I tell people is you really have to meet the person and interact in part because of the deception, but also because what happens with Internet dating is that the photograph tends to overwhelm all the other cues, and all the other cues are written statements. And we weren't really evolved to process written statements, but we were evolved to respond to physical cues. But, and men tend to attend to the visual cues much more than women. So women, in their mate selection, they have olfactory cues. So what does the guy sound like? His vocal qualities, that's auditory cues, but olfactory cues, what does he smell like? And so women have a more acute sense of smell than men do. And so if the guy doesn't smell right, even if he embodies all the other qualities women want, that's a deal breaker. And so I encourage people, just stop with the hundred texts back and forth or messaging, and meet a person for a cup of coffee and interact, and then you'll get a more accurate beat on the, the person. And then, of course, some qualities you can't assess even with a, with a half hour interaction, you can tell a lot. But things like emotional stability are things that have to be assessed over time. And so one of the things that I advise people to do, and I'm not in the advice giving business, but people ask me all the time, they find out what I study. They say, well, I got this problem. Can you give me advice? And, but one of the things to assess things like emotional stability, which is absolutely critical in long term mating, is to do something like go on a trip together, take a vacation, where you're even in an unfamiliar environment, where you have to cope with things that you're not familiar with, as opposed to an environment where it's very predictable. And so you get a greater exposure because one of the hallmarks of emotional instability is how they respond to stress. So emotionally unstable people tend to have a long latency to return to baseline after a stressful event. And so this is the sort of information you can't get on a coffee date, you can only get by assessing it over time.
A
Well, somebody whose laboratory studies stress and tools to combat stress, that's great. It's yet more incentive for people to develop self regulatory mechanisms for themselves. I'm guessing many of the features of deception in this context were present long before Internet dating, and so it's somewhat dark to think about. But is deception built into this dance that we call mate selection? And has it been built in for a long time? Or is this, or is this something that you think has emerged more as people are approaching each other through these electronic web based mediums.
B
Yeah, I mean, some forms of deception have been there for a long time over human evolutionary history. So one form of deception which we haven't mentioned is deception about whether you're interested in a long term committed relationship or a short term hookup. And so there's deception about that, especially on the part of Mendez. So men who are interested, like on Tinder, it has been reported, although Tinder denies this, there's been reported that something like 30% of the men on Tinder are either married or in long term committed relationships, and they're looking for something on the side. But in terms of successfully attracting a mate, the overt display that, hey, I'm interested in just a short term hookup. I'm interested in sex, so I want to have sex right now. Let's just go back to my apartment. These are very ineffective tactics. And so effective tactics for men are often displaying cues to long term interest. And so. And, of course, that's effective for a woman who's seeking a long term interest. And so that's a deceptive. And so we find in our studies of deception that men tend to exaggerate the depths of their feelings for a woman, exaggerate how similar they are and how aligned they are in their values and religious orientations and political values and so forth. And so I think there's deception around that, and I think that's probably an evolutionarily recurrent form of deception that women have defenses against, by the way. But I think that modern Internet dating opens the door for certain types of deception that were, at a minimum, more difficult to accomplish ancestrally. So, like things like photoshopping, you know, wasn't available back then. Plus, we evolved in the context of small group living, where you not only had your own personal observations of someone's qualities, you had also your relatives, your friends, allies, the social reputation that someone had. And this is, these are all critical sources of information that are less available in modern environments because, you know, people migrate, they move from place to place. They can close down one Internet profile and put up another, or they could have six going simultaneously. So they're. So the modern environment opens up the door for forms of deception that weren't available or weren't available to the same degree ancestrally.
A
I see. Very interesting. Would you mind touching on some of the features that are selected for in terms of sexual partner choice? We talked a little bit about mate choice, but in terms of sexual partner choice, are there any good studies exploring what people are selecting for, or is it that they are both just in a state of pure hypothalamic drive. I'm a neuroscientist, after all, and therefore it's hard to recreate in the laboratory.
B
Well, no, we do know something about that. And we know something about how the preferences for a sex partner differ from preference for a long term mate. There is overlap, of course, but one thing is physical appearance. So physical appearance for women is important in long term mating. Not as important as it is for men, but it becomes more important in short term mating. And so is the guy good looking. So those physical attributes are more important for women. They remain important for men, physical appearance in short term mating. But with the footnote that menta are willing to drop their standards in short term mating. If it's low commitment, low risk, just sex, without entangling commitments, women are more likely to prioritize what I call bad boy qualities. So guys who are very self confident, guys who are strut, guys who are a little arrogant, guys who are risk taking, guys who defy conventions. Women are more attracted to those guys in short term mating than long term mating. And whereas in long term mating, they go more for the good dad qualities. Is this guy dependable? Is he going to be a good father to my children? And then also in short term mating, women use that mate copying heuristic. That is, if there are thousands of other women who find them attractive. Women find them attractive. And so that's why you have the groupie phenomenon. So with the rock stars, for example, there are thousands of screaming women, all of whom want to sleep with this famous rock star. And they use that as information. They find if you took like a still photo of some of these rock stars and asked women how attractive the guy is versus tell him he's a famous rock star and showed the thousands of women screaming at him, they judge him entirely differently in terms of his attractiveness. And this is an important point, that women's attraction to men is more context specific and varies more across contexts than men's attraction to women. And so I'll give you just an example of that. This is a female colleague of mine went to a conference, an academic conference, and she found the organizer of this conference to be really attractive. And then saw him six months later and wondered, well, what was I thinking? He doesn't seem very attractive at all. And what it was is when he was the organizer, he was at the center of the attention structure. You know, he was the guy up on stage directing everybody and everyone was attending to him. And then when he was just a normal presenter at a conference. He wasn't, didn't command the attention structure like he did in that when he was the organizer. And so this is just an illustration of how circumstance dependent women's attract mate. Attraction is for guys. It depends on, you know, his status, the number of women that are attracted to him. The attention structure is how he interacts with a puppy or a baby, if he's ignoring a baby in distress or positively interacting with a young child, all these things. Whereas for men, it almost doesn't matter. Context is more irrelevant. They're honing in on the specific psychophysical cues that the woman is displaying in context be damned.
A
Very interesting. Let's talk about infidelity in committed relationships. What are some of the consistent findings around reasons for, and maybe even long term consequences of infidelity for men and women? And this could be marriage or long term partnership or, you know, infidelity of any kind, I suppose, yeah. So, well, I'm guessing it does happen.
B
Yeah. Yeah. Yeah.
A
Well, how frequent is it?
B
Yeah, that's the interesting thing. Well. Well, how frequent it is is difficult to gauge because it's the one of the forms of human conduct that people like to keep secret. So. So if you go back now, say, 70 years to the classic Kinsey studies, the questions about infidelity were the questions that most people refused to answer, and when the question was brought up, caused more people to drop out of the study. And so that kind of tells you something that, I mean, what do people conceal? You know, infidelity, incest, murder. You know, there's a small handful of things that people universally want to conceal, and infidelity is one of them, but people do it. And so Kinsey estimated 26% of married women committed an infidelity at some point during their marriage, and about 50% of men. Other studies have given lower figures. And so the exact figures bounce around depending on anonymity provided and how comfortable they are with the interviewer and so forth.
A
And by infidelity, does that mean intercourse with somebody else? So we're not talking about, quote unquote, emotional affairs. We're talking about sex with somebody other than their committed partner, unbeknownst to their partner.
B
Right. Right. And there are other forms of infidelity which we could get into, including emotional infidelity and financial infidelity. But here we're just talking about, for the moment, sexual infidelity. And the interesting thing about sexual infidelity is that the sexes really differ fundamentally in the motives for committing infidelity. So for men, the primary motive and these are, on average, sex differences. So whenever I talk about secondary, I'm talking about, on average sex differences because there's overlap in the distributions. So these are generalizations of which there are exceptions. So for men, it's mainly a matter of sexual variety. So about 70% of the men that we. The opportunity presented itself. I was out of town, and I had this opportunity. So low risk, low cost pursuit of sexual variety. Sexual novelty is a key motivation for men.
A
Sorry to interrupt. I just want. So 70% of men that cheat, that's the primary cause. Or is it that 70% of men do cheat?
B
No, no. Of the men who cheat, 70%. Thank you for that clarification. Of the men who do cheat, 70% cite that as the key motive, the key reason why they committed an infidelity.
A
Sort of like why mountain climbers climb mountains. Because they're there.
B
Right? Because they're there if they. Well, you know, the comedian, I think it was, Chris Rock, said, men are only as faithful as their opportunity or.
A
How available their password on their phone is to their partner.
B
Right, right. Yeah. So, but. And that's an exaggeration, but if you look at women, this just desire for pure novelty, sexual variety, is much less of a motive. But women who have affairs cite that they're unhappy with their primary relationship, emotionally unhappy or sexually unhappy, and typically both. And this may seem, like, totally obvious that, well, of course, people, if they're unhappy in the relationship, are more likely to stray, but in fact, it's not true for men. So if you compare men who are happy with their marriage and men who are not happy with their marriage, there's no difference in their infidelity rates. And I think it goes down to that issue of motive for seeking variety. Now, why do women do it? Because it's a risky endeavor. She risks her long term mate or losing long term mate. It's risky in terms of reputational damage for both sexes. So it's a risky thing. Why do women do it? And there are two competing hypotheses, at least two. But there are two primary competing hypotheses in the evolutionary literature. One is called the dual mating strategy hypothesis, where women are seeking to get resources and investment from one guy and good genes from another guy. So in principle, that can work. And I initially, this wasn't hypothesis original with me. This is Steve Gangisted, Randy Thornhill and some others of Marty Hazelton, a former student of mine, have advocated this dual mating strategy hypothesis. And originally I was endorsed it because the data seemed to support it. We can get into which data seemed to support it. But over time, I became more and more dubious about this hypothesis and instead have advocated what I call the mate switching hypothesis. If you look at a whole host of information around why women have affairs, it's not compatible with the dual mating strategy hypothesis and is compatible with the mate switching. That is, women who are looking to either divest themselves from an existing mate ship or trade up in the mating market to a mate who's more compatible with them or higher in mate value, or simply see whether they're sufficiently desirable so that it eases the transition into the mating pool or keep keeping a mate as a potential backup mate. What I call mate insurance. You have car insurance. If something bad happens to your car, house insurance. We also have mate insurance, you know, keeping some. When one woman said, men are like soup, you always want to have one on the back burner. So interesting. Whether that's the best analogy or not, I'm not sure, but it kind of captures something about why so. Well, what evidence am I talking about? Well, for one thing, women who have affairs, and this is about 70% of them, they.
A
Again, sorry, just I want to make sure people.
B
Of the women.
A
Of women who have an affair.
B
Yeah, of the women who have affairs. So let's say, ballpark, Kinsey was, let's say, roughly right, 25, 26% of women will have affairs. Let's just assume that he's right and we don't know exactly, but of the women who do have affairs, about 70% say they have fallen in love with their affair partner. They become deeply emotionally involved with their affair partner. And to me, if you're just trying to get good genes from a guy, that is the last thing you want to do is fall in love with them or get emotionally involved. But it's very compatible if you want to switch mates. And so that's sort of. That's one piece of evidence that suggests that women, the mate switching function of infidelity is a more likely explanation. Now, these two are not inherently incompatible hypotheses. In other words, it's possible that some women do pursue a dual mating strategy hypothesis. But there's other evidence that suggests so. For example, what are the actual rates of genetic cuckoldry? Well, in the modern environment, anyway, they're pretty low. It turns out they're like two to 3%.
A
Could you just explain for the audience what genetic cuckoldry is?
B
So this is where the woman, where the man believes he is the genetic father of a child, but it turns out he's not. Might be the mailman or the next door neighbor or the guy she's having an affair with. So mistaken paternity and genetic cockledry is just one way to capture.
A
Named after the cuckoo bird, right?
B
Named after the cuckoo bird, yes.
A
Who sneaks its eggs into the nest of the other rolls, destroys the future offspring of the bird, and then basically offloads all the work onto another father.
B
Parasitizes the parental investment of different bird species. So anyway, and there's other sources of evidence that I think point. So one of the sources of evidence that initially seemed to support the dual mating strategy hypothesis was ovulation shifts. So in other words, it looked like from the early studies that when women are ovulating, these are among non pill taking women, women not on hormonal contraceptives, that they experienced a preference shift toward more men who were masculine and symmetrical, which were hypothesized markers for good genes. And there's an explanation for that. But it turns out the effects of ovulation on women's mate preferences are far weaker than the initial studies looked like. And in fact, some larger scale studies have failed to replicate them entirely. And so that was one of the key sources of evidence, these ovulation shifts, that women were going after good genes, because it's only when she's ovulating and she can get pregnant by having sex with another man that it would make sense for her to have sex with another man. And there was even some early evidence that women were timing their affairs, timing sex with their affair partners to coincide with when they were ovulating. But as I said, some of these subsequent studies have failed to replicate these early findings, calling into question the dual mating strategy notion. And so I think I've shifted my views on this and now endorse the mate switching hypothesis as a more likely explanation for why most women have affairs.
A
Well, the way you describe this makes me wonder if when of the women that have affairs, do those affairs tend to be more long lasting than the affairs that men have? Because the way you described it is men are seizing an opportunity. It's a sort of a carpe diem type approach to infidelity. And women potentially, on average, are capitalizing on something that is longer term. Now, of course, if they're doing this around ovulation, then it would constrain the amount of times they would need to see or have sex with the this other person that they're not married to. But is there any evidence that women have more ongoing affairs and men have more transient affairs.
B
Yes. Yeah, there is. And so if you look at people who have affairs, there's a sex difference there. So that women tend to have affairs with one person and become emotionally involved with that one person. Over time, men tend to. Who have affairs tend to have affairs with a larger number of affair partners. And so. Which then, by definition, can't be long last. You can't have long term affairs with six different partners.
A
Yeah. Unless he's juggling multiple phone accounts or something like that.
B
Right, right. And some men try to do that, but I think it could be very taxing.
A
Yeah, well, and in this day and age, it's easier to meet more people by virtue of online communications, but it's also easier to get caught, meaning it's harder to conceal interactions. Everything's in the cloud. Anyway, a good friend of mine who's former very high level in special operations said, anything that's not in your head and only in your head is available for others to find should they want it. And I think that's largely true.
B
Yeah. And. Yeah. So phone information, text messages, and people are very good at hacking into their partners phones, computers, and then also there are video cameras everywhere. So sneaking off to this quiet restaurant, I mean, there are probably eight video cameras that can record you walking in and out of that restaurant.
A
Everything can be found. I'm certain of that. You mentioned emotional affairs and financial infidelity as well. I had a girlfriend once who, as an early date discussion, said, not that I get the impression that you are, but I want to be very clear. She said that you are not emotionally, physically, or financially tied to any other women. And I thought it was very interesting that now you bring up financial infidelity. She's quite happily partnered now and not with me. But it's interesting. It's the first time I heard anyone spell it out that way as a list, almost like specific aims in a granthead. What is emotional infidelity? What is financial infidelity?
B
Yeah, well, this is a very smart woman. Indeed she is all three.
A
Indeed she is.
B
And I assumed you gave honest responses to all of those three questions, as I recall.
A
I did, but as we now know that there. Well, you can ask her at some point.
B
And there is self deception in the service of deception is another issue. So emotional infidelity is basically exactly what it sounds like. It's falling in love with someone else, becoming psychologically close to someone else, sharing intimate or private information with someone else. That's what I mean by emotional infidelity. And one of the hallmarks of this, a study done by a former student of mine, Barry Cooleye. It was very clever. I thought he analyzed, there used to be this reality tv show called cheaters, where they would hire detectives, and they would, when the detective would, like, say, follow someone to a hotel room, they'd call up the partner and say, your husband just walked into the hotel room with someone else. Would you like to come down to the hotel and confront him? And certain percentage of people would confront. And what he analyzed, so he analyzed all these episodes of this show called cheaters. And what he examined was the verbal interrogations when people confronted their partners. And when men confronted their partners, the first question they wanted to know is, did you fuck him? Women, their first question was, do you love her? And so this kind of captures that difference between a sexual infidelity and emotional infidelity and also kind of captures another sex difference when it comes to sexual jealousy, where men tend to be more focused on the sexual components of the infidelity, because those are what compromise his paternity certainty, his certainty that he's actually the genetic father of whatever offspring ensue. Whereas love is a cue to, do you love her?
A
I.
B
That's a cue that he's going to leave you, the woman, for another woman, as a cue that. To the long term loss of that investment and commitment from that partner. And so the sexes seem to differ, in which aspects of the infidelity, with women more attuned to, more upset by the emotional infidelity, men more by the sexual infidelity. Now, financial infidelity has been explored much less. But in my new book, when Men behave badly, I have a section on financial infidelity, where I summarize all the research that has been done, and I was kind of flabbergasted by the percentage of people who do things like have credit cards that their spouse doesn't know about, keep secret bank accounts, have the credit card bills mailed to their office rather than their home, have, basically, resources and expenditures of pooled resources that they keep from their partner. And both sexes do it. And the percentages vary from study to study, but they range from, like, 30% to 60% of all people who are keeping financial information from their spouse in one way or another. It could be the woman's outlandish buying designer purses or designer handbags, could be the guys out going to strip clubs or taking his affair partner to restaurants and doesn't want those charges to show up on a jointly held credit card. So financial infidelity is critical. And then even things like diverting pooled resources to one set of genetic relatives versus another set is another thing that people tend to keep secret. So there are forms of financial infidelity as well. So, yeah, infidelity, you're. Absolutely. It's a great question because it shouldn't be confined to sexual infidelity, which is what most people think about, but also emotional and financial. Interestingly, if you ask people, what do you mean, what is infidelity in a marriage, men tend to say, well, it's obviously, she has sex with someone else. That's infidelity. Whereas women are more likely to have a broader definition of infidelity. They will cite things like emotional infidelity, financial infidelity as part of the definition, whereas men have that more narrow definition.
A
Interesting. I have a good friend who's a couples counselor, a clinical psychologist, and she told me something interesting that relates to this, which is that in cases of infidelity, oftentimes some of the arguments between couples boil down to whether or not contraception was used or not. That becomes a key feature. And she always thought that that was homing in on a detail, which, of course, is an important detail as it relates to both paternity issues and pregnancy, but also disease. But as we're talking about all this, it makes. It makes me think that this may have deeper evolutionary roots in our, further down in the brain, as we say.
B
In neuroscience literature, and using a condom versus not using a condom, not using as a more intimate act. In a way, you are literally physically more intimate with someone else than if you do use a condom. But whether there are evolutionary roots to this, I don't know. I mean, condoms are probably relatively recent, or at least a widespread use of them are relatively recent in evolutionary times. So I doubt we have adaptation specifically for them.
A
No. And presumably before condoms, one can only speculate, because, as we say, when it comes to behavior, there's rarely a fossil record, but sometimes there is. It would be the withdrawal method of contraception, which a good friend of mine whose laboratory works on reproductive biology, says the reason that's a poor choice of contraception is because it was designed not to work. So, note to those trying to avoid unwanted pregnancy. So we talked a little bit about status in terms of what men and women are selecting for different types of relationships. Is there anything else about status that you find particularly interesting and what men are finding attractive besides these waist to hip ratios and quality of potential mothers and so forth? Are there any kind of hidden gems in the literature around this that I might not have heard of?
B
Well, yeah. So you mean among the, you know, things like sex differences in what leads to high status or for instance, or what.
A
Or perhaps things that are surprising in terms of what people are selecting for. Do people even know what they're selecting for? Or is this all subconscious? Any and all of those topics are of interest to me.
B
Yeah. So. Well, to take them in reverse order, I think a lot of it is conscious, but some of it is certainly unconscious, or there are elements which are totally unconscious. So I mentioned one earlier where a man looks at a woman, he's aware that he's attracted to her and attracted to her physical appearance, but he might not be aware of why we didn't evolve to be aware of why. Just like with food preferences, we find certain things delectable and other things nauseating. We don't understand the adaptive logic of why our food preferences exist and why we have them. And the same is true of mating. And so men find women with a low waist hip ratio attractive, but they might not. They almost rarely, rarely will they know. Oh, low waist hip ratio is actually associated with higher fertility, lower endocrinological problems, lower age, etcetera. So we're sometimes aware of what we want, but we are unaware of why we want it. So I think there are unconscious elements that the whole topic of status and what leads to high status and low status is a topic I'm currently investigating, published a couple scientific articles on it, but maybe we'll hold off on that for future discussion. But it intersects, I'll mention one. It intersects with mating in interesting ways in that higher status gives people the ability to choose from a wider pool of potential mates than they would if they have low status. And so one of the reasons that people strive for status is because they have access to more desirable mates. Conversely, having desirable mates endows you with higher status. And so if you're a male, you have a very attractive woman on your arm that leads to high status. And so there's a reciprocal link between status and mating in that way. And there have been studies where they pose a kind of unattractive guy, older unattractive guy, and a stunningly beautiful woman as his girlfriend. And they say, well, what's this guy all about? And they say, well, he must be very high in status, he must be very wealthy, he must have a lot going for him. Whereas the reverse, people don't make the same attributions. And so there is an interesting reciprocal link between status and mating success, where mating success leads to high status and high status. Leads to more mating success.
A
So over and over again, there are these instances that you describe where the assessment of potential mate, sexual or long term partnership are being made in the contents of good statistical practices. Looking at the choices of others as a readout of your own choices, this seems to be a theme that this is not being made in a very narrow context, but paying attention to what other people are paying attention to seems to come up again and again, slightly off center from that, but still paying attention to what other people are paying attention to. What's known about jealousy in men versus women and how frequent it is, how intense it is, and what people do with that jealousy. I mean, we hear, or I've heard at some point that a large fraction of homicides are the consequence of jealous lovers. That's the darkest angle of all this. But in evolutionary psychology context, what is jealousy? Does it relate to paternity issues only? What can you tell us about jealousy?
B
Yeah, it's a great set of questions. And when I first started studying jealousy, I reviewed all the prior publications on jealousy. At that time, jealousy was regarded as a sign of immaturity, a sign of insecurity, a sign of neurosis or pathology, or in some cases, delusion. And what I argued is, and do argue, is that jealousy is an evolved emotion that serves several adaptive functions. One of which you mentioned is a paternity certainty function. But to back up a second, basically, once you have the evolution of long term mating, long term pair bonds, you're talking about from a male perspective, investing a tremendous amount of resources in a woman and her children over years or decades. Even with boomerang kids now, it may go more than two decades.
A
Boomerang kids?
B
Yeah, kids who leave home and then come back and live, live at home. That happens because they. Oh, yeah, that happens.
A
I don't have children, so I.
B
Okay, yeah, no, that's a big thing.
A
But if I do, I'll just expect that they'll come back at some point.
B
They'll come back because they can't find a job or they find it cheaper to live at the parents house or whatever.
A
Oh, goodness. I can't think of anything worse. I mean, I love my parents, but.
B
I know, I know. I can't imagine, but it happens, and it's happening more and more given the current economic situation. Okay, but, so once you have long term mating, you need a defense to prevent or preserve the investment that you've made and are making in long term mateship. And so jealousy serves this mate guarding function, if you will, or mate retention function. So, in other words, one way of phrasing this is that we know that there are affairs. We know that people break up, they get divorced, but people have adaptations to want to hold on to their mates, and that's what jealousy's import about. And so jealousy gets activated when there are threats to that romantic relationship, and there are other forms of jealousy, like sibling jealousy and so forth. But we're focusing on mating jealousy in this context. So now what's interesting is that the threats to an ongoing, valued romantic relationship come from many sources. So they could be, you detect cues to your partner's infidelity or cues of a lack of an emotional distance between you and your partner. You say, I love you to your partner, and your partner says, oh, I wonder how the hell the Knicks are doing this scoring season. Whatever. If you get an unreciprocated I love you is a bad cue.
A
Or a half or some people are so tuned to this, if there's a half millisecond delay, they can detect delays in responses.
B
Yes, yeah, delays in responses. But even things like. So that's one set of cues. But then there's another set of interested mate poachers. So, you know, if you're mated to someone who's desirable, which many people are, other people still desire them, and so sometimes try to poach them or lure them away from you for a short term sexual encounter or for a longer term relationship. And so we have to be. So jealousy motivates people to be attentive to potential mate poachers in their environment. But even more subtle things like mate value discrepancies can trigger jealousy. So even if there are no mate poachers and no cues to infidelity, if a mate value discrepancy opens up in a relationship. So in the american system, like, you're a six or an eight or a ten, and people generally pair off based on similarity in mate value.
A
So that tends to happen. Sixes end up with sixes, sevens end up with sixes, plus or minus one.
B
Yeah, yeah.
A
Right. So, yeah, these are somewhat subjective scales.
B
Okay? It's somewhat subjective, but there's still some consensus about these things. So even colloquially, people. Colloquially, people say things like, he's not good enough for you, you know, or, I think you could do better. So people implicitly have a notion of relative mate value and discrepancies therein. Okay. But discrepancies can open up where none previously existed. So you get fired from a job, all of a sudden, you know, and most people are very understanding and forgiving about that if it's not too long, but you go six months, eight months, people start having problems. Or if someone's career takes off, let's say a woman becomes a famous singer or actress, or a man does career takes off. All of a sudden there's a mate value discrepancy where you have access to a larger pool of potential mates and higher mate value potential. So people are attentive to mate value discrepancies. And so jealousy can get activated even if there are no immediate threats to a relationship. But that the mate value discrepancy is a threat that looms on the horizon of the relationship, because we know statistically the higher mate value person is more likely to have an affair and is more likely to dump the other person and trade up in the mating market.
A
And when people find new partners for long term relationships, do they tend to trade up?
B
On average? Yes, if the discrepancy is sufficiently large. So there are costs associated with breaking up, divorcing, for example, emotionally, financially, it's a costly thing. And so if you have, like, a half a point mate value discrepancy, you're not going to see a lot of breakups. But, you know, if you have larger mate value discrepancies, that's going to augur more for trading up in the mating market. So then you get into, so what jealousy is, it's an emotion that gets activated by these circumstances. And then what people do about it depends on what their options are. And people do things that I, in my published scientific work, I say range from vigilance to violence. So there's whole spectrum of things. In fact, I've identified 19 different tactics that people use to deal with problems once they get jealous. And one is increased vigilance.
A
And the other extreme, vigilance for the behavior of the mate.
B
Yeah, vigilance for the behavior of the mate. And that can include stalking, following, hacking into iPhones or computers, monitoring the behavior of mate poachers, looking at eye contact between other men and your partner. There's a whole suite of things that is involved in vigilance, and then at the other extreme, and we can talk about things in between. But the other extreme is violence. And so in my new book, when men behave badly, I have a whole chapter on intimate partner violence. And this is what I argue, and this is really unfortunate. And I'm not endorsing. I think it's illegal. It's bad, don't do it. But people who engage in intimate partner violence in America, something like 28% to 30% of all people who are married will experience intimate partner violence in their relationship. So it's not a trivial percentage.
A
And that violence is between the two partners?
B
Between the two partners, yes. There's also violence that gets directed toward potential mate poachers, but that's a somewhat separate issue. Okay. But one of the things that is functional about the violence is that it tends to reduce perceived mate value discrepancies. So in other words, let's say guys tend to engage in the violence more than women do, although some argue that there's more equality in the violence. But at a minimum, men tend to do more damage when they do the violence.