The Uncomfortable Science Of Sex Differences - Steve Stewart-Williams - #1120

29:56So yeah, between 0.8 and 1. And that is pretty big. That is big for a human sex difference, but there is still quite a bit of overlap. So there are plenty of women who have a higher sociosexuality than plenty of men. I guess an intuitive way to put it, a way to make it intuitive would be to say, if you imagine plucking two people at random, one man and one woman, with an effect size of 0.8 or 1, probably two-thirds to 70 % of the time, the man will score higher than the woman on that trait. So that is a majority. It's not an overwhelming majority though. In a significant minority of cases, you'd find that actually the woman scores higher than the man.

30:37Why? Why is that sex difference? That is getting right into the central question of why there are any sex differences at all. Yeah, I suppose we probably need to talk about the evolution of sex differences, why they exist in the first place. Yeah. So we should jump to that. Can I, just as an aside though, can I, we mentioned three of the six lines of evidence for innateness. Do we want to jump back and do the other three and then maybe get into the sort of thing? So what do we do? We had the developmental sex differences. We had the resistance to cultural pressure. We had the persistence across time.

31:16So another one is hormonal correlates of sex differences. And in particular, you find associations between prenatal hormonal exposure and traits found later in life. So higher levels of testosterone in the womb, for instance, are associated with high levels of aggression later, high levels of risk taking, lower levels of parental inclinations, and so on. And that's regardless of sex? That is regardless of sex, yeah. So you can look at within sex differences as well. And yes, so one actually very strong line of evidence for that claim is the fact that women who, when they're in the womb, are exposed to very, very high levels of prenatal testosterone due to having a condition called congenital adrenal hyperplasia or CAH.

32:06They, as girls and then as women, they exhibit a lot of male typical traits. Less interested in playing with dolls. Exactly. Yeah. Less interested in getting married and having kids, more interest in things related professions as well. So that's pretty interesting. Does it make them more likely to be bisexual or lesbian? Yeah, yeah, it does. It makes them more likely to be interested in other women sexually as well, either as bisexuals or as lesbians. Yeah. Wow. So like a wide range of traits seem to be influenced by testosterone. The fourth one is correlates with hormones. Yep. The fifth one is cross-cultural universality.

32:46So most of the key sex differences that we've been discussing so far, they are found either in every culture or in the vast majority. And if it were all just down to culture, you wouldn't expect that. You'd expect there to be more variation across cultures than what we found. But you don't, you know, you just always have, like in every culture, you find that men are more aggressive than women, and you find at the extreme of aggression in particular, the differences are particularly big, and you find that the vast majority of homicides are perpetrated by guys in every single nation for which we had data.

33:19Greater risk-taking, more accidental fatalities among men than women. Women across cultures are more involved in parental care, and so on and so on. And then last but not least, and maybe this is the one I find most plausible on its own, is the fact that a lot of these sex differences, you find them as well in other species. You don't find them in all other species, but importantly, you find them in species that were subject to the same evolutionary selection pressures as ourselves. And actually, the selection pressures of question bring us to the ultimate roots of evolved sex differences. so basically most sex differences emerge from the sex difference in what i like to call the maximum offspring number that male animals versus female animals can produce and in most species the males potentially can produce more offspring than females now the average number of offspring has to be the same at least in species where you have a similar sex ratio the average has to be the same, but the variance in the number of offspring produced can be greater in one sex than the other, and it's usually greater in males.

34:32Why does the average need to be the same if the variance can be different? Because it takes two to tango, and so every offspring that's produced is produced by one male and one female in most species. But if you can have one male servicing 20 females, why not have a 20 to 1 ratio? Well, that'd be a 20 to 1 ratio in terms of the number of parents, but the average number for each sex would be the same. Because you've got the one male with 20 times more than any female, and that's a really high number. But then the other 19 bachelors who never get to have kids, that brings the average for males down.

35:09And then it's the same for all the females. So you average out across all of them, and the average is the same. I get that. Maybe I'm being stupid. Why is it not the case, given that males are able to produce more children than women can, than females can, why is it not the case that there is a bias toward fewer males in the animal kingdom? Right, right. That's a great question. And that is one of the sort of early mysteries of evolutionary biology. And if selection acted for the good of the group, that is what we'd find. We'd find if you only need one male for every 20 females and selection were for the good of the group.

35:52You get that because if you have 20 of each, then the other 19 are surplus and they're using up each of resources and they're competing with each other and fighting with each other. It's not good for the species as a whole, but selection favors what's good for the individual. And for the individual - I could be the one. You could be the one, exactly. And the average is the same. So I guess useful to think about think about it from the parents' point of view. Is it better to have sons or daughters? And if there were 20 females for every one male, it'd be much better to have sons because each son is going to just have, there's going to be tons of females.

36:31And so that would mean that selection would slowly favor an increase in the number of sons. You can't beat evolution. Exactly. And the reverse, if there's 20 males for every female, then it would be better for parents to produce daughters because then they get the cream of the crop and 20 males, probably they're going to have a low number. So it's better to have daughters. So the equilibrium point is 50-50. Yeah, obviously as well, there's survival and not just reproduction. We're not living in this perfect, hermetically sealed, safe environment. Males do other things than just reproduce, regardless of whether they can do 20 to one or not.

37:06Indeed. Yeah. Getting food, helping to protect, like getting rid of other tribes, et cetera, et cetera. Yeah, yeah, exactly. And there are plenty of species where the male, his role in reproduction is just the reproductive act, and then he's off looking for other females. But we're not one of those species. I mean, that does happen occasionally. There's occasional male that will do that. But generally, we're quite involved in childcare. Yeah, so, okay, so the big difference there is, you get this difference in the variants. Some males can have tons of offspring, and they can have many more offspring than any female can.

37:46Where that's the case, though, there's going to be some males that had no offspring, or maybe a few or none. And where that's the case, you get strong selection on the males to be one of the lucky few males that has many offspring, rather than one of the few that has none. Yep. One of the many that has none. Yep. Um, and so that's the extra traits like greater aggression within sex aggression to try to beat up other males for either directly for females or for the territories, uh, the status or the resources that are necessary to attract female attention. Uh, a tendency to show off a tendency to grow a great big tail.

38:24If you're a peacock, you might want to try that grow a great big flashy tail to seduce the peahens um or just a tendency to seek multiple mates and uh and seek no strings attached sex basically so that's the answer to your earlier earlier question is that what that's why you have selection for like stronger selection on males and females for an interest in multiple partners and sex without commitment right yeah did you know your gut controls your energy your recovery how well you absorb everything that you eat and the one nutrient that keeps it all running properly is fiber. Well, it turns out that 95 % of Americans don't get enough of it, which is why I'm such a huge fan of Momentus' Fiber Plus.

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39:49That is a major contributor. And the reason is that, so this variance sex difference is mainly a result of sex differences and parental investment. So the reason that some males can have many, many more offspring than any female in a lot of species is that females invest more in the young. So in mammals, for instance, to produce any one offspring, a female has to have a long pregnancy, has to give birth to the young, and then has to nurse the young for a while. Whereas a male to produce an offspring just in principle only needs to engage in one sex act. So he can mate with multiple females and have tons of offspring because he invests potentially little in any given offspring.

40:34Whereas the females, on the other hand, they invest a lot in each offspring that lowers the ceiling for the number of offspring they can produce. Therefore, you have to be choosier. You have to be chooser about your mates, exactly. Sleeping with or mating with lots and lots of males, less useful for females than for males. But, so parental investment is really the core to… Is that the key driver? Well, I think the key driver is the difference in the maximum offspring number or the reproductive variance. Right. Because it's not just shaped by parental investment. Behaviorally, that shows up as parental investment.

41:08Well, that's a big part of it, yeah. So the parental investment is the major cause of the sex difference and maximum offspring number. But other things do come into it in different species. But gestation period too is like a biological imposition on parental investment. Indeed. Actually, is how long it takes to just make a baby considered part of parental investment? That is part of parental investment. And parental care is, and nursing is. Obviously those two, but I wasn't sure whether or not parental investment is classed as actually the making of the baby. It is because it forecloses the option to make other babies.

41:43Understood. Yeah. Yep, yep, yep. But ecological things come into it as well. So one example of a factor other than parental investment that influences the reproductive variants is ecological factors. So you'll have some species where the males, where they're quite solitary. So the males and females might pair up and there aren't many other individuals around. Um, even if the female invests a lot more in the young than the male does, their maximum offspring number is about the same because just simply because they're isolated from other, uh, members of the species, the males don't have many other opportunities to sow their wild oats.

42:18What's Bateman's principle? Bateman's principle. Um, so that is the idea that reproductive variance is greater in males than females in most species. Right. And then Trivers' sort of refinement of that was that the main cause of that is parental investment. So Bateman put a lot of it on anistochromy. He explained the difference in reproductive variance in terms of the fact that females invest more per egg than males invest per sperm. Robert Trivers, who died recently, he said, it's not just that. Actually, it's all kinds of investment that you put into the young, not just the gametes, but also gestation and parturition, which is giving birth, nursing, parental care, all those things are what matters.

43:05And I would just add that parental investment is the big one, but other things as well determine reproductive variance. What is the, it's about 40 % of males, human males ancestrally reproduced and about 80 % of females. Is that right? I have heard that number bandied about. I actually think that probably in our species, my guess is that it's not that big. I've also seen other evidence suggesting that it's called reproductive skew and suggesting that the reproductive skew in our species is quite a bit lower than you find in most mammals. And I think the reason for that is that - So the 4080 number you think is wrong?

43:43Yeah. Right, okay. I think so. I think it's smaller. Well, I think it's smaller Well, and I think because males in our species very often invest quite a lot in the young. So it's not just the sex act. They often typically help out with the young as well. And so we have high levels of biparental care in our species. That reduces the maximum offspring number for males relative to females. And brings it down, brings it closer to what we have for females. So if other animals have less of a reproductive skew, but also have less male parental investment, how would the reproductive skew for us be so great if we have more male parental investment?

44:24Is that what you're saying? That is what I'm saying. Bingo. I fucking know evolutionary psychology, dude. Don't test me on this. I fucking understand this. It's the only topic I understand. So you get variants in reproductive success. What do you reckon it was then? If it's not 40-80, feel free to just bro science it.

44:45I probably shouldn't put a number. Other than to say, I think it's smaller. I think it is smaller. I know, I know. That's why I'm in the room, dude. Let me just put this thing on for the rest of the conversation. You've got these as well. That's if you want to say something insane. Okay, cool. Well, I'll keep it here because I may well want to. In case you want to say something absolutely insane, you're allowed to put that on. It's actually saved me once already. I got clipped talking about a slightly highly postulated theory. Put that on. It's going to be interesting on you because you already have the mustache and the glasses.

45:15It will indeed. Yeah. Nothing's changed. Nothing's changed.

45:24Yeah. Okay. So we've got a, it's like an interesting, I guess an interesting pivot on what people think that sort of 40, 80 number, as far as I was aware, like actually so you think the skew is different what i thought might be true is that the overall number might be different too that the whole to me like infant mortality right fucking ruthless so the only way that we can work out how many of our ancestors reproduce presumably is due to some kind of genealogy stuff and that means that it's not how many reproduced it's how many survived yeah survive to reproduce yeah the grandparent optimizing machine from your previous book which is fantastic and everyone needs to go on like that um the April understood the universe 80 % of women having grandchildren producing 80 % of women being grandchildren producing people yeah seems insanely high to me uh I guess the thing is that they would have had a bunch of kids And only about 50 % would make it.

46:34About 50 % would make it. And so if they have sex, for instance. That's what it is, around about 50 % that are born go on to reproduce. Unbelievably high, right? About 50 % infant mortality rate. So like half of them didn't make it. One of the great things I think of our civilization is that we had lowered that number to very close to zero. Because that was, I think, a massive cause of misery throughout most of human history. yeah was it darwin lost a bunch of kids he did yeah he had uh what was it he had 10 and three didn't make it to adulthood i think that's the love is it your book or was it i think this might have been the moral animal yeah where robert wright talks about the fact that darwin lost multiple children but the one that was the most psychologically painful yeah was his daughter who was 12 or 13.

47:28And the reason for that, the evolutionary reason that Robert gives for it is that parents are able to detect the moment at which the life cycle of their child would have allowed them to just about become the grandparent optimizing machine that evolutionarily were driven to be. And that if a child dies at two years old, that's horrible, but they had a long way to go and many things could have occurred between now and being able to have kids. If a child dies when they're old, then they've had all of the opportunities to have had kids and that didn't go well, or maybe it did go well. But if you are just on the cusp of being able to reproduce biologically and you die that is from an evolutionary perspective the most painful am i making that up or is that the story no that is the story yeah and there's pretty good evidence on it as well that grief tracks reproductive value of the individual no fucking way so this has been reproduced because that book's 30 years old now yep yep um yeah go the great uh average grief levels go up and up and up as reproductive value goes up as as kids move from the very vulnerable uh historically very vulnerable early infancy to childhood it's kind of peaks at about the age that reproductive value peaks so a couple of years after puberty and then starts coming down again as people get older so fucking fascinating how is everyone not obsessed with evolutionary psychology it's so cool fascinating right it's so fun and sheds light on some of the most fundamental stuff and life.

49:07Yeah. I mean, obviously it's very bleak in some ways too. It's very stark. It doesn't paint a particularly flattering picture of human motivation. The reason that Darwin was particularly sad about his 13 year old daughter dying is that he had this weird algorithm running in the back of his mind. He said, oh, so you're just saying that all the children are, that's for you to be happy to do it's like i dude you don't need to lord our ultimate evolutionary drives yeah in order to understand and respect them and accept the fact that they are important influences on our behavior i completely agree and even you know and i do feel the pull to what like it is a bit bleak i remember when i was first reading about that grief theory it does seem a bit a bit dark but then when you think about it it's not very flattering exactly i mean i guess one thing is we're not actually thinking about reproductive value.

50:01We just have a built-in tendency to react as if we are. But we're not actually thinking in the back of our minds, this is sad because this kid was close to having kids and then I would have been… A psychopath parent. Well, this is sort of my least… I don't know, actually. I probably could write out a hit list of my least favorite internet rebuttals to anyone talking about evolutionary theory, but one of them is a lack of understanding about the difference between proximate and ultimate motivations for behavior. Yeah, exactly. So one of the big ones. Yeah. Like the misunderstandings. Why you feel the desire to do a thing and the evolutionary advantage of you doing the thing, the fact that those two things are different.

50:49You eat food because it tastes good, but the reason for eating food is to keep you alive. you have sex because it feels good, but the reason to have sex is not the reason that it feels good. Exactly right. And it's quite annoying, right, when people say, so you're saying that like sex and having like short-term relationships or long-term relationships is just about babies, but that can't be true because often the last thing people want is to have kids. I don't want to have kids. I love to have sex. Yeah, yeah, yeah, exactly. So it doesn't make sense, but they've just misunderstood the item because it's not a psychological theory.

51:23uh like the the genes i view explanations the the evolutionary explanations those are not motivations those are just the explanations for why we have the the proximate psychological drives that we do not the ultimate exactly yeah yeah and you know with the the what's it referred to as that theory of the sexual not sexual value of uh darwin's daughter dying what's the oh uh yeah Yeah. Reproductive value. Reproductive value. No one is, how horrible to say to a parent, well, it's actually Mrs. Thompson, the reason that your grief, Mrs. Darwin, the reason that your grief is so high is because of the reproductive value that your daughter almost didn't cash in on.

52:07Like horrible, horrible thing to say, but it doesn't need to, it doesn't need to be something that's in your mind to like go, how could you claim that this mother is feeling that, thinking that at the time and that's contributing to a grief. No. Yeah. She's not. She just loves the kid. Yeah. It would be the same as going, why is it that people get depressed when they're lonely? I'm not thinking about potentially being kicked out of the tribe. And you go, well, yeah, like we're in a modern environment. Why do you think it is that depression and anxiety correlate with isolation? Yeah. Yeah. If it didn't matter?

52:42Well, it does matter. It doesn't matter anymore, not in the same sort of a way, but that doesn't negate the fact that our system is basically ancient programming living in a modern world. Exactly. And even though it does seem bleak sometimes, I don't see that other explanations, sociocultural explanations, would be any less bleak. Oh, so you're telling me that I'm at the mercy of the memes and trends of the modern world? Well, exactly. Some guy decides to start a new cool movement somewhere, and then that completely sort of blows the wind of whatever it is that I'm supposed to care about? Exactly.

53:16Or you might say, okay, the reason that you grieve this individual is just because you've been socialized to do so. How is that any less bleak? This is why I think there's a lot of similarities between evolutionary psychology and behavioral genetics, that if you start to strip away the science and the evidence underneath it, what you end up with is an equally or maybe even uglier perspective in the world. For instance, if you deny that there are genetic influences on outcomes in life, what you're left with is this world where everybody did start off equal and you are exclusively at the mercy of the entire world.

53:56And injustices. Yeah, yeah. The only reason that this didn't come out is all on your shoulders. It's all on your shoulders because you didn't try hard enough or your parents didn't try hard enough. Yeah. Horrid, horrid. And I guess, though, the thing is that whatever horrid truth, and they're not all horrid either, but whatever horrid truth, ultimately we've just got to accept what's true, whether we like it or not. And, you know, sometimes it is positive. So natural selection has given us a whole range of less than noble traits, but it's also given us some really lovely traits as well, like the capacity to fall in love and to love our children and to love our friends.

54:31You know, these are all great things. To care for others, to do selfless things. Yeah, exactly. Okay, so I guess just to round out, we haven't even got into the sex differences yet, which is the meat and potatoes of this, but I don't care.

54:46Are humans unique in this regard? Because we've got mutual mate choice and we've got bi-parental care. So when we're talking about evolution of sex differences, parental investment, ability to produce children, volume of children across a lifespan, Bateman's principle, variance in reproductive success. but humans do seem to be somewhat of an outlier in mammals and especially in the animal kingdom. Yep. Yep. What wrinkle does that throw in? Well, yeah, so the question, are we unique? Sort of yes and no. So the way in which we are unique, we're very unique among mammals, like you say, and the fact that we have high levels of the tendency to pair bond, so to form love and form relatively durable pair bonds.

55:32And for both sexes, rather than just the females to invest in the young. That is found in maybe 5 % to 10%, 10 % at the most, of mammals. So the overwhelming trend among mammals is that the females do all the investment in the young, and the males are basically deadbeat dads. In birds, on the other hand, they are an outlier family of animals among animals in general, and that around 90 % of birds form pair bonds and have biparental care. And so there's a funny thing, and I find this just very, very interesting, is that in our primary reproductive behavior, humans are more like the average bird than like the average mammal.

56:13No way. Yeah. That's because of our pair bonding and our biparental tendencies. Which is a reinforcement that the parental investment is the key driver of sex differences. Yep, exactly. And the difference in the area. Hang on a second. Yeah. So. Steve Stewart-Williams and Chris Williamson.

57:05A way in which we're not an exception though, is that the same evolutionary principles that apply right across the animal kingdom apply to us as well. So the fact that sex differences emerge from the maximum offspring number, the level of sex differences and reproductive variants, that is true across the animal kingdom. And the rules about that apply to us as well. And the fact that we do have a sex difference in reproductive variants. men do have and have always had greater reproductive variants than women, but it's relatively low compared to most mammals. Most people have no idea where their testosterone levels sit, but what if I told you there was a solution?

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58:19Normally, this level of testing would usually cost thousands, but with function, it's$365 a year. That's$1 a day to stop guessing with your health and start knowing. And right now you can get$25 off, bringing it down to$340. So get the exact same blood panels that I do and save$25 by going to the link in the description below or heading to functionhealth.com slash modernwisdom using the code modernwisdom at checkout. Isn't there an interesting inversion of this in spiders where female spiders are bigger than the males? Actually, most insects, it's that way around. And actually there are more animals where the females are bigger than where the males are bigger.

58:58but that's not because there's a difference in reproductive variants it's because in a lot of species the main driver of sexual dimorphism is just the number of eggs that you can produce and females bigger females can produce more eggs so there's a selection pressure on them to get bigger and bigger and bigger they're typically bigger than the males the males don't need to be much bigger they don't need that much room for sperm yeah exactly so the gamete size difference sperm are bigger than eggs is reflected in the physiology Oh, that's so fucking cool. And we're the weirdos. We're so used to males being bigger than females, but actually mammals and other large vertebrates were the exception to the rule.

59:38And the main reason for it is that you still have the selection pressure on the females for producing more eggs. So, you know, they've got certain size, sort of push for them to be bigger. But you've got an even stronger push on the males to be bigger as a result of intersexual selection, which is selection for the ability to be able to beat each other up basically so a lot of species bigger males do better and fighting than smaller ones males get bigger than the uh males get bigger and sometimes they get even bigger than the females all right meat and potatoes getting back to sex differences and sex drive yeah what casual sex sexual variety cheating what's going on there yep uh that's all about producing more offspring so um a male that is equipped with those motivations is going to be sort of like a heat-seeking missile going out to seek multiple partners and is therefore more likely to have more offspring if he's successful than that than he would if he just sort of sat back and wasn't interested in multiple partners.

1:00:42And you do find that in many species. Now, I don't think that the difference is as big in our species as in many others. And I think that's a side effect of the fact that because we have biparental care, the level of reproductive variance among males in our species is somewhat constrained still greater than among females but because it's somewhat constrained sex differences in our species have correspondingly come down as well so we still have all the traditional sex differences that you find in most mammals and many other species but they're somewhat muted so you have the sexuality sex differences but they're somewhat muted the aggression differences but they're somewhat muted um the parenting differences is the main source of this so that you know is like uh the discrepancy in male investment in kids versus female investment is has been massively reduced and that's the driver and that's the bi-parental yeah the bi-parental investment is the nerfing the reason for the nerfing of all of the others okay again i i'm only going to make this fucking disclaimer once uh but we said it we said it previously but i think it's worth saying again.

1:01:46Just because we can explain using evolutionary logic, the reason why men might be driven to cheat more than women is not the same thing as excusing why it happens. No, not at all. Any more than a sociocultural explanation would excuse it. That's a funny asymmetry. People seem to think if you explain it in evolutionary terms, that excuses it. But there's no more reason to assume that than to assume that if you explain it in sociocultural terms. Because with both of those, you are outsourcing the culpability of the individual to something else. In one, it's evolution and ancestors, and in the other, it's culture and influence.

1:02:23Yeah, exactly. And all our behavior must have causes, right? So if we're going to say that if we can identify the cause of a behavior and it's an evolutionary cause, we're going to have to not hold people to blame. We're going to have to say that for any cause, and we're going to have to say that for all behaviors, because all behaviors have some kind of cause, whether or not we know what it is, they have some kind of, whether it's evolutionary or cultural or most likely a combination of both. Yeah. So I think that basically the institution of holding people responsible, we have to keep that institution because it's useful regardless of the fact that of course people's behavior has causes and it's not inexplicable.

1:02:57That's so good. Ashley Madison, the cheating website had 20 million active male users and 1 ,492 active female users despite women getting free lifetime membership and men having to pay. Yeah, that's wild. That's a massive difference. 20 million to 1 ,500. It's probably similar to that ratio we had up there before. It's almost exactly the same. Yeah. What about men being more turned on by visual triggers? Yeah, that's another big sex difference. Both sexes are to some degree, you know, both sexes are interested in good looks in a mate, but it's stronger in men than in women. and the main reason for that is that the traits that we consider good looking are associated with youthfulness and fertility for both sexes but men place a greater weight on those traits because of menopause basically so the fact that they place more weight on youthfulness in a mate because youthfulness is more closely linked to fertility in women than men because of the fact that women's fertility shuts off about two-thirds of the way through the lifespan Yeah.

1:04:02So, yeah. So men are much more interested in visual sexual stimuli, as psychologists call it. It's part of the explanation for the fact that men are much more avid consumers of porn than women are. What is the reason that women are much more avid consumers of romanticcy and romance novels than men? It's an interesting one, isn't it? So that's the standard sort of differences in consumer preferences that we hear about. Men are much more into porn than women. Women are much more into romance novels. Now, it is interesting. We've talked about the fact that men on average are more interested in casual sex than women.

1:04:39And people often assume that the flip side of that is true as well, that women are more interested in long-term relationships than men. But actually, that's not the case. Typically, what we find is that men and women are about as interested as each other in long-term committed relationships, in falling in love and forming a committed bond with a partner. So you haven't re-apportioned the sex drive, relationship drive, desire from short-term to long-term for women. It's just that they don't have this addition that men do of the one night stand. Exactly right. But bearing that in mind, the fact that women are so much more interested in romance novels is interesting and sort of slightly unexpected.

1:05:24You might expect that both sexes would be interested in them. So why it is the case that women are more interested in them? I guess, evolutionarily speaking, I don't know. They do seem to be, despite the fact that actually men do seem to be very invested in long-term relationships. A bunch of papers have come out recently actually saying that in a lot of ways, men are kind of more romantic than women. They are more likely to suffer after a breakup. Fall in love more quickly, say I love you more soon. Exactly, exactly. So why aren't they more into romance novels? I don't know maybe they're just too busy with the with the porn but yeah true I did I mean I sat next to a lady lovely lady floral dress slightly slightly older lady on a flight a few months ago and uh she had a ipad up resting it and it was a big big fuck off font yeah and she was reading some romantic thing and she was getting to the good stuff and uh I mean I couldn't I was like we We have legalized women reading porn in public.

1:06:24And it's not, I mean, she seemed to be having a wonderful flight. And I got my, when someone sits next to me and they've got an iPad, I think, oh, that's great because it's going to, or whatever, a Kindle or something, it's going to influence me to not be a degenerate. All I wanted to do was put a pair of blinkers on and focus on some brain slop stuff. I've never, I've never, um, I've been meaning for ages as a sort of anthropological study. Excuse it however you want, dude. Excuse it however you want. I haven't got around to doing it. I'm going to do it. I'm going to read a romance novel at some point.

1:06:57I have heard that the general theme is boy meets girl. Boy is a bit of an arsehole. A girl tames boy. And then they live happily ever after. And they do involve sex, right? Well, yeah. I mean, there is some sex in them. At least there was in hers. And the one that she was reading. Yeah, exactly. Um, I mean, there's some interesting stuff, right? The number of, if you have a single a sexual fantasy mental sexual fantasy men will cycle through i think it's between four and six different partners on average during four and six or 46 four and six i think but it depends who you are um whereas for women they tend to have fewer yeah maybe maybe just one now i don't know but i'm gonna guess that this would be reflected in romance novels in fact i know that this is the case because i've been on the cover of a bunch of them and during those novels, at least I would say on average most, the women who are the protagonists aren't cycling through multiple male suitors.

1:07:55And if they are, even if you look at movies, movies like The Notebook or Titanic or whatever, it tends to be a pivot between two different life directions. It's not a kind of ruthless conveyor belt that is closer to sort of the typical male fantasy. But yeah, the men being more turned on by visual triggers thing, I think makes an awful lot of sense. I remember in Bad Men, Bussie's book, he talks about how there is an area of the brain that exists in men that lights up when they just see something that's remotely sexual, a pair of rocks that look like boobs. Pulling a coin into a vending machine.

1:08:35Putting a coin into a vending machine. You're fucking kidding me. Although it was a joke. I'm not sure there's actually research on that. That honestly wouldn't surprise me. No, no, likewise. There is something penetrative about gambling and it was on top of the risk taking on top. That's it. Overperception bias as well. Another great example that I learned from Bad Men by David. Yeah, yeah. And that's some research by him and spearheaded by his former student, Marty Hazleton. Yeah, the sexual overperception bias. Yeah, that refers to the fact that men are more likely to infer sexual interest on the part of a woman falsely, like falsely inferred, than women are in the case of men.

1:09:17They're more likely to think, yeah, she's into me, when actually they're just in a little dream world and that's not actually true. Men are more likely to think that women are interested in them than they are and women are more likely to think that men aren't interested in them when they are. And I think that the data shows the level of attraction that men assume a woman has toward them is roughly equal to the amount of attraction that the man has toward the woman. Yes, right. Yeah, exactly. So it seems to be maybe some kind of projecting yourself into the world kind of bias. Yeah. So it's a failure of cross-sex mind reading, but it's also specifically in an overperception bias here too.

1:09:58And this is smoke detector principle. If you as a man had the opportunity to potentially bag an available and attractive woman, and because you weren't sufficiently vigilant and detecting it, because you underplayed your potential success likelihood as opposed to overplayed it, you are going to have an error of missing the opportunity as opposed to the error of an awkward and clumsy rejection. Exactly. And this, again, fuck, I'm just going to have to keep saying it, does not excuse guys in the workplace with the receptionist in the printing room having an awkward fumble that she absolutely didn't give off signals for.

1:10:36However, this does explain how you get to that situation or why it is that on average men seem to be, unless you're the CEO of, who was it, Procter & Gamble, who was the one that that Indian dude made the whole fucking conspiracy theory about. It went insanely viral. I bet your fishhead Asian wife doesn't have these cannons. Do you remember that? Goldman Sachs. Goldman Sachs. Yasmin's mum works at Goldman. We should get the inside scoop.

1:11:08Yeah, my guest book is mum is like real high up at Goldman Sachs. And then there was that huge... Did you see this thing kick off a couple of months ago? I don't think I did. Or about a month ago or so? No. It was a guy me too-ing a very, very high up exec. Yeah, a bit of a role reversal. A Goldman. But as soon as the proposed accusations came out, there was no... It was so rare. It was at the most... It would have been incredibly extreme for a guy to do. And the fact that everybody intuited, like, really? Yeah. Sex differences. How do gay men and lesbians reveal what each sex wants? They do so in a very interesting way, which is that gay men have more casual sex than straight men, and lesbians have less casual sex than straight women.

1:12:00And the reason is that gay men and lesbians don't have to compromise with the typical sexual inclinations of the other sex. And therefore their behavior is like a clearer window onto the sexual motivations of men and women in general. Unsullied by the other sex. Exactly. Exactly. Yeah. So men are compromising by having less because basically women are thwarting their plans. Yep. There's no gatekeeper. Exactly. And yeah, whereas straight women are compromising with men and maybe having more than more casual sex than they would choose, at least as revealed by lesbian behavior. there's an interesting study that Rob brought up, which was inside of marriages, typically men say that they would like to have twice as much sex as they are having.

1:12:46And women say that they are happy with the amount of sex that they are having, which suggests that there is a compromise going on. Yeah. But that the compromise is the guy going, okay, fine. She's setting, she's setting the level more than he is. With that regard. I do think that there's kind of a, and this is, I mean look are we really gonna say boohoo poor men not getting exactly what they want but I do think that it's a a kind of compromise that might be invisible to women because sexual entitlement comes wrapped in some really ugly uh paper but there is an argument that you can make there to say something like look men are doing a type of containment a type of desire containment there that isn't a burden that is that they are paying that isn't being paid in the same way inside of a marriage by the women and huh that's well done well done for doing that for compromising what it is that you want yeah indeed and i guess uh and i guess it's more it's more i guess that um men are doing that more often like some women are doing the same thing no doubt but that's just fewer women than men in that situation.

1:14:02There's also more dead bedroom in lesbian relationships. I've heard that, yeah. There's some phrase like that, isn't there? Lesbian dead bed or something. Okay, so mate preferences. Yes. When it comes to mate preferences, is it surprising how similar men and women are when it comes to what they look for in a partner? Well, I guess it fits with the generalization that in a lot of ways we are quite similar, that sex differences in our species are not as huge as in some others. And I guess also just on an everyday level, when you hear about some of the sex differences that we have in common, they're all things that I think it's obvious why we like them.

1:14:45People tend to be, men and women, tend to want somebody who's pretty intelligent and who's kind and who loves them and who is attracted to them and who is pretty good looking and who's not mentally unstable. Both sexes want that, not just men, not just women. There are some areas, though, where you do find sex differences in the strength of different preferences. So both sexes want someone who's pretty good-looking, for instance. But on average, in long-term relationships, that's a bigger deal for men than for women. Men put more weight on looks in a long-term mate than women do for the reasons that I mentioned earlier.

1:15:28women on the other hand tend to put more weight on resources and status and a long-term mate than men do now now in neither of those cases is that the it's not like looks at the most important thing to most men for most men it's important but other things are equally important or even more important traits like kindness and likewise with women um resources and status and a mate They're important, but other things, again, like kindness, tend to top the list of the things that are most important for women. Most people don't realize how much being dehydrated impacts their performance, which is why for the last five years, I've started pretty much every morning with Element.

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1:16:39Plus, they offer free shipping in the US. Right now, you can get a free sample pack of Element's most popular flavors with your first purchase by going to the link in the description below or heading to drinklmnt.com slash modernwisdom. That's drinklmnt.com slash bottomwisdom. What's the evolutionary logic of non-physical mate preferences like wealth and status? It all comes down, I think, to the fact, well, there are two main explanations for it. So one is that it's part of our evolution of a pair bonding biparental species. So a guy who is able to access resources, you know, bring in food and also has good standing within the group, that's going to be someone who is better able to invest in the young, to co-rare the children.

1:17:24And that's the explanation I think is most popular and most likely. There is also an explanation, though, that it's primarily a human equivalent of the peacock's tail. So that any male that is capable of bringing in resources and climbing the status hierarchy, that's a male who's got good genes and he's going to pass on whatever traits enabled him to do that to his male offspring. they're going to be able to do the same, they're going to attract more mates. So those are the two main explanations. I think it's quite possible that both of them shed light on it, that it's both a fitness indicator, but also is actually useful in the context of bi-parental care.

1:18:01You mentioned this is to do with long-term relationships. Yeah. How does this change when it comes to short-term relationships? Do women place more or closer to equal weight on physical attractiveness in men? They do. They do, yeah. So that sex difference in good looks, we sometimes hear it discussed as if that's the difference between men and women right across the board in every context. But actually, it does just apply to long-term relationships. And when it comes to low-commitment relationships, then that difference basically evaporates and women are at least as interested in physical attractiveness in a mate as men are.

1:18:39If not, some research suggests they may be even more interested in physical attractiveness. Why would that be the case using evolutionary logic? Because, well, the best explanation is that in a short-term context, that's likely to be, um, uh, basically there's going to be no further investment, probably, uh, likely no further investment. The only investment is the genes that the male is going to be passing on and therefore traits that are indicative of good genes are much more important. They take center stage in terms of what women are looking for. And yeah, with the basic evolutionary logic that when you're reproducing, you are finding somebody to mix your genes with.

1:19:21If you want your genes to go on in the gene pool, you've got to mix them with a good set of genes from another individual. And what you want, if you have a short window to do this assessment and you want the most obvious representation of those good genes as you can? Exactly. And physical looks are that. I'm sorry, your ability to do non-kin altruism and reciprocal care and kindness and your ambition over time. It's like, yeah, great, but I don't have time to assess that in the same way as I do your status and your resources. I suppose it's another one of the reasons. And both men and women, if this sex difference didn't exist, if this preference didn't exist, why would it be the case that both men and women seem to play into a caricature of that in an attempt to get sexual access?

1:20:08Why is the caricature of dudes in Miami nightclubs wearing a Rolex and having a fast car outside? Well, that's a way to turn wealth, ambition, and status, buying a VIP booth, status, into an immediately transactable and obvious advertisement in case there is some of this short-term mating that's going. And why is it that women do more beautification when they go on a night out, et cetera, et cetera? Like, because you're playing into, even if you don't intend on doing it, it's always nice to sort of be window shopped against, I suppose. Totally. And it's interesting, right? Because these are human equivalents of the peacock's tail.

1:20:50And whereas in peacocks and every other species, basically their peacock's tails are non-negotiable. That's just how they do it. Whereas we, because we're a cultural animal, we always have our peacock's tails. We always have our way of showing off status and whatever else, resources. But it varies from culture and culture and time to time. Why isn't it that women aren't turning up in a fast car with an expensive watch outside? That's a very interesting question. And I guess because that's more indicative of resources, and resources are more important to women than men. I don't know. There was this study where this guy, it wasn't a study actually, this guy in his class, his evolutionary psychology class, he was showing a photo of this amazing Rolex and people saying how great it was and what a great way of attracting a mate that it would be.

1:21:41And then he revealed the trick was that actually it was a woman's Rolex rather than a man's. And his point was that actually this goes in both directions more than we kind of think it does. Have you seen, I think it's Andrew Thomas that did this study. Have you seen the preferences that women state when it comes to sperm donors? Yeah. So this is fucking fascinating because what's interesting is when you run a kind of a split test or you're able to separate out certain motivations from a behavior that people are typical with. So in order for you to do the, I want to have kids with this person, typically you need to go through courtship phase and get to know them.

1:22:29And even if it's a one night stand, be seduced by them. But that means that you're optimizing for two different things. You're not just optimizing for the genes that your kid gets. You're also optimizing for the expression of traits that make you want to get into bed with somebody. But if you get rid of the seduction side of this, all you're optimizing for is what do I want my kids to have from a trait perspective? And that difference of when you get rid of the need to actually be attracted to somebody, and you can just optimize for what do I want my kids to be like. Kind of fascinating. It's really fascinating, right?

1:23:04And just the same mate preferences emerge in that context as emerge in actual interactions, social interactions. There's that Clark Hatfield study as well, right? The on-street interview? yeah yeah that's the one where um uh basically they got a bunch of good-looking guys good-looking gals to go around a campus on a nice day uh walk up to random people on the campus and just say hello how you doing um i've noticed you around the place lately and find you very attractive and i was just wondering whether you wanted to dot dot dot and then they would finish that sentence with one of three options option number one was i was wondering if you wanted to go out with me tonight.

1:23:44Option number two was, I was wondering if you wanted to come up to my room. And option number three was, I was wondering if you wanted to go to bed with me. And they got men to ask women, women to ask men. And for the first question, the go out with me question, in the first study they did, there was basically no sex difference. So it was about 50%, 50-50 likelihood of saying yes in both cases. Other replication studies have found that it's not a huge difference, but that actually men are more likely to say yes than women are. But then with the other two questions, the gaps get bigger and bigger.

1:24:16With question number two, which is, would you want to come up to my room? What was it? It was basically in the first study, about 67 % of men said yes. So actually higher than the date rate. More likely to go up to your room than I am to go on a date with. Exactly. Hilarious. With women, on the other hand, it sank down to, I I believe it was 6 % said yes to that. And then the gap was even bigger for the last question, unsurprisingly. So would you go to bed with me? 75 % of men said yes to that offer. So at an even higher rate of men, whereas exactly 0 % of women said yes to the kind offer. And not only that, but actually the manner of the refusal differed between men and women.

1:25:03So of the 25 % of men who said, thanks, but no thanks. Well, they kind of said that. They were polite about it. And some of them said, I'm really sorry, I'm meeting my fiancé or whatever. A bunch of them even asked for a rain check, apparently. They said, I'm not very busy. I'm meeting my fiancé or whatever. But maybe we could postpone the sex till later. Whereas none of the women who were refusing were polite about it at all. They were more, they were reacted more like, are you crazy? How dare you ask me that? None of them apologized and asked for a rain check. Why do you think that the manner of refusal was so different?

1:25:41I think that it reveals two reasons. One is there's this average difference in interest in casual sex. Because men are more interested in it, they are more likely to be flattered by the request. Because men are much more likely to approach women than vice versa, traditionally, women are much more likely to get sick of it and to have to push guys away. Whereas guys, it's a rarer event for them, so they are more likely to be flattered and hugely grateful on the rare occasions when it happens. The other thing though, and the reason I think the difference is quite so big, is because it's not just a reflection of sex differences and interest in casual sex.

1:26:24I think also in that situation, like if a woman were to go off with a guy that she doesn't know, she's at a greater physical risk than if a guy goes off with a woman that he doesn't know. So the fact that the difference was massive is partly due to that as well. Feels like a danger. Exactly. Some of that emotional activation of, hang on, I'm going to go with this person who I don't know, who is physically stronger than me. Yep. Explosion. as opposed to this just way less of a, it feels less of a physical threat to me. Exactly. Those both make complete sense. There's an interesting wrinkle in this.

1:27:05Now, I'm going to guess that when they did this, the Clark Hatfield study, they must have done some sort of rated assessment of the attractiveness of the man or the men versus the women to ensure that they were similarly high in terms of physical attractiveness. Yeah. right yeah so something that i learned that i think is absolutely fucking hilarious is one of the reasons why women and i presume men would be too if women approached men at the same rate one of the reasons why women are sometimes quite rude when guys come up to them is if they feel like there's too big of a disparity in mate value between them and the person doing it because they go hang on you think that you've got a chance with me yeah oh my god it's basically an insult yeah it's essentially an insult if you as a woman think that you're an eight nobody thinks like this it's not the whatever podcast you as a woman think that you're an eight yeah and a guy that you think is a three comes up to you that is yeah it tests your own self-perception and you go fuck maybe this is how the world sees me yeah do you not think i'm an eight yeah as well yeah yeah and i think that that it feels like an insult and the same thing like fucking no get away because rightly so you're kind of pissed that this thing happened i wonder if guys would feel the same in reverse see my hunch is that they would be less likely to take it as a huge insult if the guy felt he was an eight and approached by three well preference for casual sex yeah uh rarer approach in any case.

1:28:43And because women are less likely to approach, I think that most guys would actually see it as closer to, you know what? I'm so good looking that I got that girl to overcome her non-approach predisposition. That's the power of my attractiveness. I think that's how a lot of guys would take it. And I think that's why it is flattering. It's like somebody running for a bus fast that they really, really want. You're like, well, they must really want this bus because look at how fast they're going. And guys tend to be more overconfident than women. Yeah. What about sex differences in aggression? Sex differences in aggression are very, very consistent, especially for direct aggression, so face-to-face aggression, and guys predominate.

1:29:31And a really interesting fact about the aggression sex difference is that for verbal aggression, it's there, and it's significant. It's fairly modest though. So the effect size might be about like a 0.5 effect size. So half a standard deviation between the mean for men and women. And maybe, you know, pluck two people at random, guy and a gal, two thirds of the time, the guy is going to be higher in verbal aggression. But as you go further out to more and more intense forms of aggression, the size of the sex difference gets bigger and bigger with every step. So when you go to low levels of physical aggression, slapping, pushing, that kind of thing, that you have a larger sex difference men doing it more then you get into serious physical aggression violent crime that's much more men this is independent of who the victim is independent of who the victim is yeah um and then when you get to the extreme of one-on-one aggression which is homicide uh men vastly predominate so across different cultures every single nation uh every data set i've ever seen 90 plus percent of homicides are perpetrated by men men are also They're the majority of the victims as well in almost all data sets that I've seen.

1:30:43But yeah, the 90 % plus perpetrators, very, very strong effect. Yeah. Men commit more than 90 % of homicides in every society on earth where data is available. And this gap is remarkably invariant across cultures, not just the absolute rates. In humans, males commit 95 % of homicides and a 70 % to 80 % of homicide victims. in chimpanzees, male commit 92 % of chimpsides and are 73 % of victims, virtually identical numbers to humans. It's wild, right? Yeah. Now they are more aggressive than us. I think sometimes people hear that and they think that the claim is that we're just as aggressive as chimps, but they are more.

1:31:18But the size of the sex difference in lethal aggression is the same. And the size of the targets, the sex difference in the targets of aggression is about the same as well. Why? That is a direct offshoot of the fact that it's the selection for getting to be one of the few males that has many offspring rather than the many that have few or none. And one of the ways that males do that is they compete with each other for status and resources, which increase their mating opportunities. species. And so you get selection in many species, not just humans, selection for greater aggression in the males, and particularly for greater male-male aggression, which is why you have this skew toward not only the other males more aggressive, but the targets of their aggression tend to be same-sex individuals as well.

1:32:09For women and for female animals in general, they are capable of aggression in many species, but there's just less of a selection pressure. It's less useful for them evolutionarily to engage in same-sex combat for status and resources because of the fact that the ceiling offspring number that they have is lower. So they can't vastly increase the number of offspring they have by fighting each other and getting lots of status, resources, and ultimately mates. That won't boost the number of offspring they have because the ceiling is lower. So it's costlier for them. The costs aren't worth the risks.

1:32:44Yep. Plus more fragile. more easily killed, like just generally. Yeah, but that's possibly just an offshoot of the fact that there's been less selection on them for aggression. So there's been more of that on males. So you don't need to build up the defenses in order to be able to. Exactly. That's why we have a brow ridge. That's why we've got bigger hands. Exactly, yeah. Tell you what's interesting. Again, talking to Andrew Thomas about this, he said, why is it the case if violence is rightly so such a huge fear that most women have, that lots of women are attracted to powerful men who are able to be violent.

1:33:23And Andrew's theory is that it's a perspective that a guy who is violent is able to turn it on and turn it off in service of the family unit, as opposed to violence being a trait that just is more global across the board. I think, has Andrew done Krav Maga? He's into martial artsy type stuff, I swear. I think so, yeah. And he was explaining how many, at Krav Maga, this Israeli martial art, very lethal, supposedly, martial art. A lot of the guys that he trained with, unbelievably lethal physically. And a lot of the training was them learning to turn it off, not turn it on. Interesting. And that the number of men who are physically imposing and might seem like somebody that would be really great to be able to protect the family unit that have done the work to be able to learn to turn that off to the trigger that makes this person likely to be a flash in the pan, you don't want to fuck with me, bro guy, at least non-zeroly are also going to have some triggers that will be more sensitive when it comes to interpersonal communication and domestic disputes and things around the house.

1:34:48Indeed. It's interesting, isn't it? Having that kind of temperament, violent temperament, and the capacity for physical aggression is really a mixed blessing for women. It's great if the guy's going to protect them, protect the family, but it's not so great because he can potentially turn that against them as well. And so, you know, you get the evaluation of those traits. It can increase attractiveness. Like aggression itself, I don't think increases attractiveness. Protectiveness does. Muscularity and the like can increase attraction somewhat, but because it's a mixed blessing, I think women are also interested in the guy's character.

1:35:24Muscularity seems pretty reliable at improving attractiveness. Yeah, yeah, yeah. And it's probably the most easily modifiable thing that guys can do. Right, yeah, yeah. In fact, I think William said that this is exactly the case because he's looking at his incel stuff. Did you see, now I bro science this, I put the captain of bro science hat on when Macken came through last time. Yeah. And I said, I'm pretty sure that I've seen a study that says a woman would be, would lose more attraction if her partner didn't protect her during a physical altercation than if he cheated on her. Right. And then the guys went and replicated it And you were right.

1:36:07I was right. Excellent. Excellent. I mean, it wasn't my original insight because I found it in a study that I couldn't discover again. But the same insight being true, the protectiveness, the ability to protect. In fact, do you know what it is? It was the willingness to protect. Yes. It wasn't even the ability to protect. Yes. But I suppose willingness to protect is the most important part of protectiveness. Because you can be the biggest guy in the world, but if you're not prepared to step in between your missus and this potential assailant, it doesn't mean anything. You might as well not be.

1:36:33Exactly. you know yeah i wonder do you know what it is i wonder if this would be this is another new skew that the guys should do yeah um is it more or less attractive for a guy who could protect you to not than a guy who couldn't protect you to not that's an interesting one you know what i mean but in terms of the character trait it would be less attractive for the guy who could protect you but doesn't, right? That shows a worse character. Yep. But I guess it does also matter. I just need to train him to be able to in future. There is that, yeah. I need to teach him to be able to be strong enough to be protective or I need to be able to change his character in order for him to use his strength of potential protectiveness.

1:37:21Yeah. Yeah, but if he's definitely not going to do that, that's going to be very off-putting and you might just want the person who is not quite so good at protecting but is willing to do it if they can do it. That's amazing. There's trade-offs though, right? Why is it that women care more about a man's height than women do? Is it plain to this? I think it probably is. I think it must be. I think it's within a cluster of traits that determine protectiveness and the like. Muscularity, height, they're all part of the same package. And it's interesting, right? They does seem to be really, really high on the list for women.

1:37:52It seems to be very important. You know why this makes the most sense? And it's probably, yeah, I would go as far as to say it's the most commonly cited, well, you bitches, internet kind of rebuttal that guys have around, I think Tinder released as an April Fool's joke about 10 years ago, a height filter that people could use. Wouldn't it be funny if we gave you a height filter? That's now an actual feature. It's an actual feature, right? Yeah. um and many women don't need to date or don't want to date men that are under six feet uh especially not men when you get sort of like five seven five six five five very few would and i had this insight the tall girl problem uh and it was born out of a friend whose sister is five foot two sorry her sister's five foot eleven um so if she wants to wear heels on her wedding day she's looking at professional athletes.

1:38:50And they were going around the supermarket and she saw this guy who was like six, five, like tall dude, like you, tall guy. And she sort of nudges her sister and says, I might go up, I might go up and talk to him. And they round the corner and they say, see him with this five foot two Latina bombshell. And she kicks off at her sister quietly and says like this fucking bitch. Like she could date five foot five, five foot six, five foot seven. Why'd you have to take a guy that's a foot and a half taller than her? But the point here is if we're talking about protectiveness as the driver, the fact that your chick is a 5 '2 Latina, not a 5 '11 American does not make your height any more or less useful when it comes to protectiveness.

1:39:42I don't need to protect you less just because you're smaller. yeah yeah yeah indeed you know yeah and this is why i think you don't see much of a height compensation effect yeah other than i guess if you're five foot two you can't really tell the like i don't above probably five ten it's all just up there yeah it's just like it's over there you know in the clouds exactly yeah my cousins my cousins are quite tall because i'm from a tall family and i know they were complaining often i remember them complaining female cousins uh about guys, taller guys dating much shorter women. But guess how tall my wife is.

1:40:19She's five foot four. These bloody bitches, how dare they take the tall man? All right. Sex differences and stalking. What about that? Women do a lot more of it. Joke. Men do a lot more of it. Men do a lot more of it. I think it's just an example of the fact that men are more proactive, seeking out mates, seeking out multiple mates, and stalking is the subcategory of that when it gets into inappropriate examples of that. And also, I guess, yeah, it's not just mate-seeking, it's also when people get fixated on somebody. And both sexes can do that, they can get fixated on somebody. Sort of limerence type thing.

1:41:03Yeah, exactly, limerence. So sort of falling in love, except that we call it limerence because it's in an inappropriate circumstance, i.e. a circumstance where the other person does not reciprocate. Both sexes can do it, but men are more prone to aggression and risk-taking and just bad behavior. And so they're more likely to do more of those kinds of behaviors in the context of limerence and being fixated on somebody. What about surveillance, surveilling of a partner checking in? Because I could see two reasons why either side might be doing it more. male parental uncertainty, which we haven't talked about yet, but is super important that no woman has ever given both to a child and wondered whether it was hers.

1:41:45But many men have looked at, maybe even all men to some degree. In fact, it would be evolutionary useful for you the first time that you look at your kid to be so beautiful. And are those my eyes? Yeah. Yeah. I think they're my eyes. But given the fact that you have high male parental uncertainty because you've got concealed ovulation and you don't have the same kind of sort of harem, hermetically sealed sphere when it comes to men and women, human men and women, stalking, I could see a surveillance behavior, could be a part of mate guarding to try and counteract that. But I could also see how it would be useful for women in order to ensure that their partner doesn't leave them high and dry because there's more of a dependency, especially if we are going to have a kid or do have a kid.

1:42:39The man doesn't need the woman as much for survival, but the woman doesn't need to check on the man as much to ensure female parental uncertainty. Yeah, that's exactly right. And both sexes do get jealous. Paternity uncertainty or parental uncertainty is uniquely an issue for guys. But you're absolutely right that there is the danger of desertion for women. And so for different reasons, both sexes have evolved to be jealous and prone to jealousy. And one way that that manifests, so jealousy drives mate-guarding behavior and one subset of mate-guarding behavior is surveilling and just keeping an eye on what the person is up to and are they getting on too well with that good-looking next-door neighbor or the good-looking guy or woman at work.

1:43:27And then if you take that to an extreme, that's where it becomes surveilling behavior. Isn't it interesting that you have an extreme insight of men about other men and an extreme insight of women about other women? But the failure of cross-sex mind reading still occurs even when you add other individuals in? So when we're talking about surveillance, jealousy, mate guarding, et cetera, the i mean william put these stats up recently about how what the percentage is of men who would sleep with a female friend it's huge yeah it's like 50 percent of relationships used to be friendships yeah yeah yeah uh so that's like 50 percent yeah that's a huge amount and i think uh when you put all of this together you end up with a world where inside of a relationship men are trying to explain to women what they see in other men that are around them and women are trying to explain to men what they see in the other women that are around them and just because it's not them talking about themselves doesn't mean that they can explain it a woman is no better at understanding another man than her own husband and a man is no better at understanding another woman than his own wife in these sort of uh more subtle uh hard to detect motivations and um that those data that uh that william was talking about um so so yeah so like a lot of guys would be interested in sleeping with friends that they have right but it's not true in the other direction like fewer uh some women but fewer of them um are particularly interested in sleeping with uh male friends that they have but because of the sexual overperception bias the male friends in question would probably assume otherwise.

1:45:15What's the sex difference around sexual violence? Sexual violence, men are much more likely to do it. And that is just partly just an offshoot of the fact that men are more aggressive. Yeah, and the numbers are pretty big. So sexual violence is much more often perpetrated by men than by women. It doesn't only go in the one direction though, but it is just much more common for men to do it. Do you get any idea what the numbers are? I probably do. Let me have a think. Okay, so I do have a few numbers coming to mind, but I'm not actually sure if they're the right numbers. So I'm going to, again, do the annoying academic thing.

1:45:52Directionally correct, specifically big. Indeed. So directionally correct, and I've got to say that it is a big difference. Yeah. I think the effect size might be something like two. So like two standard deviations between the mean for men and women. For the extreme forms of sexual violence and sexual assault and harassment and the like. Yeah. Another situation where it's kind of hard to talk about evolutionary explanations for bad behavior, like the worst behavior, right? Between this and homicide without sounding like you're excusing it is natural. Exactly. But again, natural doesn't mean good.

1:46:29You can explain bad stuff without saying that actually the bad stuff is not good stuff. It's still bad even if it has an evolutionary explanation. Yeah. yeah yeah it's that uh analysis is not justification yeah yeah exactly uh you know that's a fucking hassan albi quote that's like a hassan piker quote he got canceled he got canceled for talking about some stuff to do with the right wing yeah that is an absolute slammer of a line analysis it is true justification yeah uh but we can see sexual violence if men are able to procreate without having to do any investment, the ultimate form of that is to not even have to ask for consent as well.

1:47:10Yeah, yeah, indeed. And it has been argued that the tendency in some men to do that, to take that path, does have evolutionary roots. And I guess really you just have to have two things. You have to have men's greater interest in sexual variety and casual sex, coupled with their willingness to use violence in certain situations. So because men are more interested in casual sex, it's going to be not uncommon for a man to want to have sex with a woman who doesn't want to do so. And because men are willing to use violence sometimes to get what they want, every now and then you are going to have that situation where those factors add up and the man is going to try to force the woman to have sex.

1:47:58It's not as found in our species. Males in many species try to coerce women, females rather, into sex. It happens in our species. It's also been argued though that because preserving female choice is so important across the animal kingdom, including in our own species, so important to women, that that helps explain why sexual coercion and rape is so upsetting to women. you know it's not we haven't just been socialized for it to be upsetting to women it's very very deep in females nature to be upset by it because it compromises female choice oh that's interesting yeah that's interesting because not only not only is it fucking heinous but you know that because somebody because this male committed that behavior they've had to disregard the entire female-wide value that is supposed to be universally protected.

1:49:02Well, right. Well, I mean, she's evolved this tendency to be choosier about her mates than men have. And she's got these mate choice criteria because she can have fewer offspring and therefore each offspring counts for more. So she's got to be wiser in every mating decision that she makes. And this other male has come along and has just taken that away from her, taken that choice away from her.

1:49:29She's evolved to be choosier and has gone against that. I think that the inability of men to fully understand what fear of sexual violence must feel like is one of the reasons why any guy who's seemingly sort of flippant or callous about any type of male-female aggression, even non-sexual violence, is treated with a very strong antibody response. from women. Indeed, yeah. And guys do, you know, guys, the idea of going to prison and being raped in prison obviously is terrifying to a lot of guys. So they do get it to some degree. But, and I guess particularly when it comes to the sort of lower level stuff, like I think in Bus's Bad Man book, he talks about research suggesting that men often will underestimate just how upsetting it is to women to be sexually harassed and to have stuff done to them against their will.

1:50:30And that's another very good example of a very important example of a failure across sex mind reading where the guy just doesn't really appreciate just quite how upsetting it is for that to happen because if it would happen in reverse if it would happen to him he might not like it but he on average is not going to be quite so upset by him it's interesting that people who denied sex differences seem to sort of not want to argue for parity that if women weren't so held back they'd want to commit just as much violent crime as men do. Indeed. Yeah, indeed. There's a directionality to the way that this analysis happens.

1:51:05Yeah, there is. Why is it not that we've got 50-50 in terms of homicides that we should do? Yeah, yeah. Women should be free to commit just as many killings as they want to. Yeah, and they've just been kept down the fact that they're not doing it. Yeah, the patriarchy, the damn patriarchy. And I guess the thing is that they and we all would want it all to come down. And it's a good example of how equality is not necessarily good thing in itself. So men are more aggressive than women. The solution to that is, so we want to kind of reduce male violence. And in the process of doing that, we're going to reduce the size of the sex difference.

1:51:42And that's a very good thing to do. But the reason it's a good thing to do is not because there's anything inherently wrong with the sex difference, it's because violence is bad. It's not because the sex difference is bad, it's because the violence is bad. And we know that because another way to get rid of that sex difference and violence would be to increase the female level of violence. And that would be big thumbs down on that, right? That is going to make the world a worse place rather than a better place. So the point is, yeah, equality is not a good thing in itself. Yeah, yeah, yeah. Okay, what about the differences in parenting?

1:52:13Differences in parenting, that's quite a controversial one, actually. That's one of the ones that people like least. The aggression sex difference, no worries about the parenting sense difference people aren't so keen on. And that refers to the fact that in every culture, again, where we have good data, women do more of the direct parenting than men do. And they invest more in the young. They do more parental care. Men in every culture do more than your average male chimpanzee or male walrus, but they do less than women in every single culture. And that doesn't seem to just be because men are forcing women to do it.

1:52:50They do seem to be average differences in terms of parental inclinations with women being more interested in doing it than men are on average. And yeah, I guess the reason that it's controversial is that there's a concern that people are making up an excuse why you should do it. So guys are using it as an excuse. It's just natural that you should want to be changing the nappies and doing these things that coincidentally I would rather not have to do. um so that that i think is the concern but in a way it's ironic so the fact that people consider it to be kind of an insult to say that on average women are more interested in parenting than men um implies a negative valuation of parenting or doing more of the parenting because if it didn't imply a negative valuation of that it would not be an insult to say that women on average this has been one of my most one of one of the best ideas i think i've come up with over the last couple of which was the soft signal of male expectations.

1:53:49Yeah, yeah, yeah. I think you mentioned that when we met the first time, right? Yeah, yeah, yeah. The soft bigotry of male expectations. Soft bigotry of male expectations. It's like as if we treat the male standard. Whatever men do, that's the standard of what is right. And if women do it less, that's a bad thing, and we should make them more like males, but not so much the reverse. Yeah, and it is very ironic because - It's a really misogynistic worldview. It is really, isn't it? It is, it is. And so if we're taking a negative valuation of parenting, which is what we are implicitly doing if we say that it's an insult to say women are more parental, we're implicitly, and if it is actually true that women on average are more parental by nature, then we're taking a negative valuation of a more female typical trait, and that is really sexist.

1:54:35Yeah, yeah. What's the kibbutz experiment? The kibbutz experiment, there were these kibbutzim that they had in Israel. So these were these communes, highly Egaritarian communes, where they wanted to get rid of all traditional kind of structures, including traditional male-female ways where the woman is expected to do all of the childcare, and the guy is out in the public doing the public stuff. She's at home doing the private stuff. So what they did was they would get all the kids and they would house them in communal houses. And then they would have dedicated adults within the group who would be primarily in charge of looking after all the kids.

1:55:19So the kids weren't living under the roof of their biological parents. They didn't think, you know, the idea was everyone should care for everyone rather than having this traditional, what they saw as bourgeois approach where people are specifically interested in their own biological children. They want to get rid of that. They tried it. They did manage to make it work for a while, but what happened was that just the parents hated it, basically. The parents hated not having their own kids living with them under their roof, and they agitated and complained about it, and eventually it broke down.

1:55:54And the interesting thing was that although both parents hated it, the mothers particularly hated it. And a lot of the agitation came from the mothers more than the fathers. And it's a great example, a great case study, because we often hear that women are placed in the primary caregiver role by men. They may have kind of forced them into that role. But here was a case where actually the women in particular were rebelling against the male leaders to try to put themselves into that role instead. So it's another example of a very common phenomenon where you see certain behaviors and certain aspects of human nature that emerge and persist despite culture rather than because of culture.

1:56:40Culture's pushing in the opposite direction. Actively going against it. Exactly. Yeah. I saw this really heartbreaking video of a woman on TikTok. She was at work in a cubicle, looked like a sort of normal office cubicle. And she had a screen up of maybe the daycare that her kid went to. And she was seeing, watching her kid say. It's first words or take its first steps. And it was just one of those ones with a caption over it that said, like, me being devastated that I'm at work while my kid is going through one of the most meaningful experiences at the start of its life and I'm missing it. It's tough, right?

1:57:21There's a real, that's the work, family, you know, clashing roles that both sexes do experience, but it does seem to be still a bigger deal to women than men. Yeah. It's certainly not something that... People are happy to talk about maternity leave and the lack of maternity leave as being kind of barbaric. And I agree. I mean, the UK gives nine months, which is still not enough, but feels at least remotely humane. yeah um and the u.s is basically once you're out of the hospital you're back to work yeah uh but very few people i think it's not a big cultural conversation around what is missed by either the need to go back to work to keep yourself financially stable or the desire to go back to work because of expectations that have been adjusted on women about where their value comes from this soft bigotry thing again.

1:58:14I don't want to be just a mom. But by being not just a mom, I'm also missing out on a lot of the joys of motherhood. It's kind of hard to win that situation. Women really don't have a good outcome there. Yeah. And people in general, I mean, in a way, there are these kind of trade-offs for everybody always. And choosing one option always does mean not choosing another one. I know that a lot of people solve that problem to some degree, to the extent that it is solvable. A lot of women do by taking some time off, more time off, taking a career break, in other words, when the kids are young. But then particularly when they go to school, then getting back on the career course.

1:58:59What about differences between men and women in sexual jealousy? That's an interesting one. So both are prone to it, like I mentioned. but for the reasons that you mentioned already, men's jealousy is more focused than women's on sex. So a sexual infidelity, like if you ask men, which would upset you more? Your partner who you love going off and sleeping with somebody else or just forming a close emotional bond with somebody else? Now both of those are upsetting to most men, but men are more likely to say that the sex is more upsetting than just the bond. And you pose the same question to women.

1:59:39And again, both of them are upsetting to the vast majority of women, but they're more likely to say that the emotional bond, the sort of falling in love, maybe falling in love with the other person, that that's more upsetting than just sex per se. It's interesting, right? And it comes out of the fact that men had this problem of paternity uncertainty. Like you say, no man in the history of the species has ever, no woman in the history of the species, ever given birth and thought, now how do I know that this is my kid and not some other woman's kid? Whereas for most men, more than likely it is their own kid, but there is always some non-zero chance that actually it's not, that it's the good-looking next-door neighbor's kid instead.

2:00:22So yeah, that's why sex is a more important issue for men than women. Women are more likely to be left holding the baby and that is not good for their fitness because it's going to reduce the time before they can have another kid and just make things a lot more difficult for them. And so it's obviously not great if their partner sort of sleeps with somebody else. It's not great. They'd be very, very upset about it. Very often it destroys the relationship. But it's even worse for most women if the partner gets emotionally involved with somebody else because then whether they want the relationship to end or not, it's going to end because they're very likely going to leave and set up shop with the other woman.

2:01:03I have an example that I heard about from a while ago that a friend was on 23andMe or Ancestry.com and one day in their 30s got an email notification saying, you've got a new half-sister. Right. And she says, how the fuck have I got a new half-sister? What it turns out was that 32 years ago, the dad had had a one night stand affair that kid had never met the father never been involved again but three decades later this situation unfolds and uh obviously awful awful to try and live through but i would have been fascinated to have done a study to work out what happens to what happens to sexual jealousy and intimacy jealousy and the fear of, uh, resources, resource provisioning needing to be split when you've gone past all of those things, because you have this, you know, three decade, assuming that there's not been more infidelity, this three decade example of someone committing to the family and raising the kids and doing the rest of this stuff and also the person that would have been the dependent is no longer in need of any of the provisioning you understand what i'm getting at to like separate out all of the typical areas yeah trust infidelity all of those things like obviously horrible but kind of kind of fascinating too it is really fascinating and i wonder if this could be an example where proximate and ultimate, thinking about the proximate and ultimate might solve the mystery because it's possible that, because we don't necessarily think about, we don't necessarily think it through, we're not necessarily thinking, well, I'm going to lose this partner.

2:02:55He's going to fall in love with her and he's going to go away and then I've got this baby and I'm going to have no one to help me with it. That's the evolutionary rationale, but it could just be a gut reaction, like he's getting close to somebody else, I hate that, I feel jealous, I feel bad about it. And so that could kick him just as strongly 30 years down the line when it doesn't matter anyway. You know, like you say, trust issues and those kinds of things are going to kick him. Could kick him just as strong, even though evolutionarily the circumstances, it doesn't matter anymore. The gut reaction that evolved might not discriminate those details.

2:03:30What do we know about sex differences in personality? Well, there are some and they're pretty consistent. They're not huge. Two of them are bigger than the rest. Now, if you're thinking about the big five personality traits, so the OCEAN acronym, so openness to experience, neuroticism, extroversion, agreeableness,

2:03:50and conscientiousness. I got that in the wrong order. That wasn't OCEAN, but those are the five. So the two sex differences that are largest and most consistent are the sex difference in neuroticism, which is proneness to negative emotions like depression and anxiety, plus emotional volatility, so ups and downs. And that is about a medium effect size. So I guess it's usually estimated between about 0.2 and 0.5 standard deviation between men and women. There's that one. And then the other consistent one is the sex difference in agreeableness. And women on average score higher, again, it's not a massive difference, heaps of overlap, but again, it's 0.2 to 0.5.

2:04:34I would say it's a small to medium sex difference as well. There are some sex differences in the other three big five traits.

2:04:46Often, not always. You sometimes find that women score a bit higher in conscientiousness, but not always. Some studies don't find that. Extroversion, on average, women's slightly higher on extroversion, but again, not always. And it's a smaller difference if it is one. Uh, and then, uh, uh, what's the other one? Conscientious. Openness. Openness. Yeah. Openness. Slightly higher for women as well. All no difference. What's the explanation for why those would be the case? Uh, well, I, I don't think we know for sure, but my best guess, so then the neuroticism sex difference. So that's proneness to things like anxiety and depression.

2:05:24And I think women, there's a general trend where women seem to be more self-protective than men. which is kind of the flip side of the fact that men take greater risks than women. They're more risk-taking. I think that that evolved because that is about trying to propel yourself up the status hierarchy. You've got to take risks in order to do so. And men have evolved to do that more than women because they have a higher maximum offspring number. But yeah, the flip side of risk-taking is to be more self-protective. Part of that is to be more prone to anxiety. The function of anxiety is the same as the function of the turtle shell.

2:05:59It's to protect yourself. It's about protection. So I think that's why women are more neurotic. Now, the agreeableness, sex difference, so women on average are more agreeable. I don't have quite as strong an idea about that. I do think that, well, I guess it could be the flip side of the fact that men are more aggressive, more pushy, and that evolved, like we've discussed, to try to, again, get up the status hierarchy, beat rival males to go up in the world and achieve status and resources. Women have evolved to do less of that, and one manifestation of that is the fact that they're more agreeable, more friendly, more compassionate.

2:06:41And just the way that women have evolved to form social bonds, it does tend to have a higher level of compassion and understanding the other person that seems to be more common in women than men. What about the people versus things divide? So that's an interesting one, right? That is a bigger difference. That's actually quite a big difference. It's one of the bigger psychological sex differences. And the effect size there is like one standard deviation or even a bit more when it comes to people versus things. very very consistent i think there's a good case that it is not just due to socialization so so one thing is that like i mentioned earlier it has persisted for as long as we've been measuring it very very consistent even when the culture is trying to push against it and get women more interested in things related professions traditionally male professions seems to be related as we also mentioned uh seems to be related to prenatal hormonal exposure and one thing i haven't mentioned already is that it's also very very cross-culturally consistent So there was one study that had about 200 ,000 people in it and found that sex difference in career-related interests, found it in 53 out of 53 nations.

2:07:51And another one had half a million people and found it in 80 out of 80 nations. And that level, it's amazing, right? That level of cross-cultural uniformity, you just hardly ever find it in the social sciences, but you do find it for that difference. And this has been around for a hundred years? Yep. Yeah. It was first documented in 1911? Yeah, that's right. That's when they first documented it, and it's been consistent ever since. It's one of the biggest differences, and I always find that pretty interesting really, because the kind of careers that we have today are evolutionarily novel. So you might not necessarily expect that to be one of the biggest sex differences.

2:08:27Interest in careers that just haven't existed throughout the vast majority of evolutionary history for our species. But it's there and very consistent. And there's been some deliberate effects, attempts to try and close it as well. Indeed. And they're ongoing. And it just doesn't seem to budge, really. It's interesting that the soft bigotry of male expectations happens with get more women into STEM as well. Yeah, indeed. As opposed to get more men into traditionally female dominance. Exactly. But, you know, Richard Reeves, who has been on the show, right? And that he's trying to get more men into those kinds of professions.

2:09:03He's trying to do it. But again, I think the reason that there is a publicly lauded push toward getting more women into STEM is because of that soft bigotry. Agreed. And if you look, I'm going to guess that if you look at the gender equality paradox, you're going to find that in more gender equal nations, fewer women end up going into things-based roles. Yep. And more men go into things-based roles. That is exactly right. Yeah. And just the interest in it gets bigger in those cultures as well. Regardless of what you do. That's an interesting one to have, to separate out what jobs are available to you and can you get from what ones you're interested in.

2:09:44Yep, exactly. And both expand. And it's interesting. Now, I think that you're right that it does reflect the soft bigotry of male expectations. I think people who want to close those gaps also will typically point out that those kinds of professions pay more as well. And that's another reason to try to close the gap. But that doesn't change the interest. It doesn't change the interest. I mean, some people are interested in things because I went to university and did business because I thought I could get a job in it. So I became interested, but it was a very transactional type of interest. Interesting.

2:10:20So yeah, how many people develop an interest in a thing because it's functionally useful for them to acquire resources in it? You know, it might depend. And I would say that in a pretty wealthy society, that more men than women do that. In poorer societies, I think it's more common for everybody to do that. You know, in poorer societies, you just think, well, I would love to do whatever it is, impressionistic dancing or whatever. But you get some, in high inequality and high poverty environments, you get some really interesting outcomes. You've seen Candice Blake's work on the female beautification.

2:10:56I have, yeah. Remind me of the details. So they analyzed, it was either Instagram posts or tweets and correlated them with the level of income inequality in the local ecology. And in areas with higher income inequality, women did more self-sexualization and more beautification. Yeah, yeah, yeah. Interesting. And supposedly the proposed mechanism for that is when you see not only how high you could climb, but how low you could fall, you try to maximize your ability to be assisted in being dragged out of that from a resource provisioning perspective. Yeah, yeah. It's cool research there, right? Yeah, it's really cool.

2:11:26But basically, it's just when material restrictions are in place, stuff gets warped and squirrely because people are concerned about survival. I mean, you've seen the environmental security hypothesis as well about men are more attracted to bigger women in times of poor economy and more attracted to skinnier women in times of good economy. Yeah, it's interesting. And there does seem to be pretty good data on that. I am not 100 % persuaded of the evolutionary arguments for it, though. You could survive a famine. There's a famine imminent. You couldn't survive a famine, but it doesn't matter because we got loads of food.

2:12:06Indeed. And I mean, it does make sense. The logic there does make sense. But I mean, is it the case that for a long enough fraction of human evolutionary history, we had feasts and famines. I'm sure we did have that. But were the feast periods big enough that people were actually getting big. I mean, my impression is that hunter-gatherers, they just didn't really get big enough that there would have been selection. It would have been very, very, very rare. Exactly. It would have been almost impossible before, what, 13 ,000 years ago? Yeah. It would have been almost exactly impossible, definitionally, because you could only eat what you could carry.

2:12:43Exactly. There was no surplus at all. That's interesting. So I sort of feel like it couldn't have - Well, Mark is here today. We can fucking grill him about it. We can talk about that, yeah, because he's a fan of that, right? Yeah, he is. Well, he likes the sort of behavioral ecology approach to things. He likes humans as plants as well as humans as animals. So we grow toward the sun and how is the local ecology imposing and warping. But definitely the self-sexualization in high income inequality makes sense. Yeah. And I do agree with the general principle that we've evolved to respond to the ecology.

2:13:18I'm just not sure in that case it could have evolved because there weren't fatter people around the place for long enough. What about cognitive abilities? Is there a sex difference? Cognitive abilities, if anything, I would say that's probably the most controversial topic that I deal with in the book. Let's bury it two hours into the episode. So there are some. I guess a few things to say to try to avoid getting cancelled. is first of all that there are no sex differences in the cognitive ability that matters most to most people, which is IQ or general cognitive ability. There is basically zero sex difference in the average there.

2:13:59Now, when you say that, some people will say, but that's because IQ tests have deliberately been constructed to create equal averages. And that is true. Some of them have, some of them have, but there are some IQ tests. To offset the sex difference? Well, that's the theory. And so some of them have been deliberately created that way, but some haven't. But even those ones that haven't been created specifically to give the same outcome and balancing spatial versus verbal and that kind of thing, even when they haven't, they give basically the same averages with representative samples of people. Now, sometimes you'll get some studies that will have males doing slightly better on average, but I'm persuaded by the argument that that is because the very low IQ males are more likely to fall off the map, fall through the cracks and kind of disappear and not end up in the samples than the low IQ women bringing down the female average.

2:14:58Because we do have a higher variance. Yeah. Right. Yeah. In cognitive abilities, there's higher variance. Yeah. Average is the same. The variance is slightly greater. in men than in women. More male geniuses and more male retards. That is exactly right. But important to note that that's quite a small effect. And that is, this is the controversial area, and that's maybe the most controversial claim within that controversial area. So I always like to follow that up by saying, so that people hate that because it's a cognitive advantage that gives an advantage to guys, but there are also the cognitive ability sex differences that give the advantage to women.

2:15:36So women on average are better verbally. That is one. And another one is that among the minority people who are really, really gifted at maths, the women are more likely than the men to also be gifted verbally. So they're more likely to be a double threat. That's cool. So no average differences in IQ. where you do find differences, they're just as likely to favor women as men. In some cases, men are slightly better. Spatial abilities, that's an example. Verbal abilities though, women tend to be somewhat better. And then most of the differences are small. So they're smaller than the personality differences.

2:16:17They're much smaller than the differences in interests. So when it comes to cognitive abilities, we're much more alike than different. But having said all that, there are these average differences in these specific abilities. And that, like it or not, that just is the fact of the matter. And that's been measured for a hundred years as well. There's tons and tons of data on it. Typically found across cultures, very likely, I think, to be partly innate. It's shaped by culture as well. You can minimize it. And I guess also in principle, you could increase it as well. But yeah, I would be surprised if it's just due to socialization.

2:16:55What about physical health? Physical health, there are some definite sex differences there. One of them, and the one that's probably best known, is that men are more prone to cardiovascular disease than women, more prone to heart attacks in particular, at least among like in 50s and 60s. Until very old age, men are more prone to those. women are more prone to immune system disorders. They're more prone as well to pain disorders. Men are more prone to most forms of cancer, other than sort of reproductive cancers that only strike one sex or the other. Men are somewhat more prone to cancers as well.

2:17:35And actually one of the big ones is that men die younger on average than men in the vast majority of cultures, including even most cultures where women have high rates of death during childbirth. so we drew the short straw there eunuchs in the korean chosin dynasty lived longer than intact males of identical social standing demonstrating that testosterone has a direct biological cost to male lifespan that is very true so i touch on that in the book in a billion billion years of sex differences i write about how actually most people probably don't know this but we do actually already have an intervention that we could in principle do which would completely obliterate the average difference in lifespan between men and women and would extend men's lifespan, and that is castration.

2:18:20It's got to be castration before you hit puberty, though. So, you know, sadly enough, if anyone wants to take that approach, if you've already hit puberty, it's too late. But yeah, the fact that it would work is, it's interesting, does show that it's testosterone that is making us bigger, stronger, more aggressive, but also shortening our lifespan as well. If male mortality rates were lowered to female rates, Randy Nessie, who did the evolutionary medicine studies, calculated we would save more years of life than if we cured cancer. Male mortality, we're at female rates. We would save more years of life than if we cured cancer.

2:18:55Yeah. So we're so used to it, so used to the fact that men die younger that we don't really think about it, I think. But then when you do think about it, yeah, you find that that is a massive, massive difference. And then we've got 88 % of Darwin award winners, which are people who die through spectacular self-inflicted stupidity are men, but 90 % of Carnegie Hero Awards, which are given to people who risk someone's life in order to save a stranger, also go to men. So the risk sort of cuts both ways. It's almost exactly the same. 88 % of people who die through stupid self-inflicted ways are guys, and 90 % of people who risk one's life to save a stranger are also guys.

2:19:32Yeah. So that is the trade-off there of risk-taking, right? In fact, almost by definition, taking risks can pay off big time, but can also kill you. Winners and losers. Yeah, exactly. And because men do more of that risk-taking. I mean, that's one of the reasons I think that you get more males than females will start a business that does really, really well. And people focus on that and they think it's unfair. I'm going to guess more will go bankrupt too. Exactly. Exactly right. Yeah. They're more likely to go in both directions. So they're more likely to succeed because they take bigger risks, more likely to fail because they take bigger risks.

2:20:05Some people, when they hear about that, they think, well, we should encourage women to take bigger risks. But the problem is that they are then, to the extent that they do that, they're opening themselves up not only to greater chances of success, but also to greater chances of failure. Yeah, risk doesn't just cut one way. Totally, exactly. So my solution there, I think, would be just tell everybody all the facts. Tell men and women all the facts. This approach to life, this risky approach, cuts both ways. You could go up, you could go down, do what you want with that knowledge. and that's my approach to just a lot of gender gaps in general right so like workplace gender gaps tell people all the facts try to get rid of i mean just do everything we can to get rid of bias and barriers but then having done that um respect people's choices about their own lives and how they want to live them and what careers they want to do what's really interesting about that is if you try to compartmentalize the information that people see and you don't give them full access to the information.

2:21:07What you end up with is actually a world in which there's more likely to be resentfulness and you need to do more compensation on the back end because people have made decisions under imperfect information. Yep. Yep. That's exactly right. And some of the steps I think that people take to try to balance out gender gaps in the workplace, I think can have exactly that effect, creating resentment. There's one of the dangers really, I think, of overstating the extent to which gender gaps in occupations are due to bias and barriers. I do think it's absolutely essential to look at the extent to which they are due to those facts, but I think we just, to bias and barriers.

2:21:53I think we also don't need to look at the extent to which they're due to preferences as well. Because if we don't, first of all, if we say any kind of gaps that you see are products of discrimination, first of all, it's going to create unnecessary resentment because you're going to say, look at these gaps. That's because of men mistreating women. Second, it's going to lead to costly interventions to try to eliminate the gaps. And those interventions are probably not going to work because they're targeting things that are not the causes, the primary causes of the gaps in the first place. Then what happens is, because they don't work, we start doing more and more coercive things to try to eliminate the gaps.

2:22:34In some cases, we do anti-male discrimination, kind of inadvertently, just trying to eliminate the gaps. We get a bit more coercive and end up, instead of getting rid of discrimination, which is what I think we should do, we end up reversing the direction of discrimination, which I think is just creating, it's not undoing past injustices. It is just adding to the sum total. Additional injustices. Exactly, exactly. And reverse ones. And then that can create a backlash among guys. And then also if we exaggerate the extent to which discrimination is behind those gender gaps, like in STEM, for instance, we say you have these gaps in STEM, more men than women go into it, and it's just because STEM is just riddled with sexism, it's a horrible, horrible, hotbed of sexism, that's going to put a lot of women off, girls and women off, who might otherwise go into it.

2:23:27So ironically, this effort to try to fight it could actually create the reverse. You touched on it earlier on. What about differences in mental health? Mental health. So there's the neuroticism, sex difference, first of all. Women are more prone to depression and anxiety, just sort of day-to-day depression and anxiety, rather than clinical levels of it, but at the extreme of that distribution, they are also more prone to clinical depression and clinical anxiety disorders. Men are slightly more prone to schizophrenia. Men are much more prone to antisocial personality disorder, sociopathy, psychopathy, more likely to be psychopaths.

2:24:10What else is there? I'll tell you one where you don't find a sex difference is bipolar disorder. I'd say in the book that that's the least sexist disorder on record because it's basically the same. Across cultures, it's about the same frequency of both sexes. What's your explanation for why we would have these differences in mental health? Well, with the depression and anxiety, I think that's just a side effect of the neuroticism sex difference. So at lower levels, it's adaptive for women to be, girls as well, but especially women to be somewhat more anxiety prone because they protect themselves more and they're not taking risks in a way that is more adaptive for males because of the higher maximum offspring number.

2:24:58So it's adaptive at that level, but I think that because you have a distribution, it means that inevitably some people are going to be the extreme of that distribution. I don't think it's actually adaptive out there. So I don't accept adaptive explanations for clinical depression or clinical levels of anxiety disorders. I think that there is a sort of non-adaptive or actually maladaptive often byproduct of sex different. Kind of a spandrel, yeah. So just a side effect exactly of differences that closer to the mean are adaptive. The schizophrenia difference, I don't have a theory about why that is.

2:25:34And I don't think that there is a theory yet about why that is more common among men than women. Something I didn't mention, actually, autism is more common among boys and girls. ADHD is more common among boys and girls as well. So yeah, ADHD, I think that, again, that's just a sort of offshoot of the fact that boys are kind of more active on average than girls and sort of less attentive and more likely to get distracted and running around the place. And it's not a problem in the usual. I mean, it might be irritating for parents and teachers, but it's not a big problem in the normal range. But at the extremes, it is quite a problem.

2:26:14And it's a problem more often suffered by males than females as an offshoot of the differences that they mean. After going through all of this, doing all of the research, obviously you've been deep in this for a long time. Yeah. and then doing the book what happens or what's your fear when people don't respect sex differences or they deny them what what's the sort of world that we live in if that happens it's a good question and i think it's a particularly good question because we're always focusing on the dangers of exaggerating sex differences and moralizing sex differences and i think there are lots of problems with doing that and we need to be careful not to do it um but where i think i disagree with a lot of folks is that i i think that there are also problems with doing the reverse.

2:26:57I think there are also problems with minimizing sex differences and denying them. So one thing is that just as in exactly the same way that some people who exaggerate and moralize sex differences, they try to push people into traditional gender roles, people who deny the differences or massively minimize them, they're in danger of trying to push people out of gender roles. So kind of replacing one gender straitjacket with another unisex gender straight jacket or like a maybe reversed, gender role reversed straight jacket. And then we've actually touched on another of the big problems, I think, with minimizing the differences, which is the fact that trying to explain gender gaps in society like occupational gender gaps, there's just a whole host of problems with doing that that we discussed.

2:27:44Other problems with minimizing sex differences is that there are certain physical health problems and mental health problems. So not only do the frequency of different problems differ between the sexes, sometimes the symptoms differ as well. They present differently. So like cardiovascular problems present differently for women than men. Women are more likely than men to have shortness of breath as a symptom rather than sort of shooting pains down the arms and the other kind of classic problems like that. And if you don't focus on sex differences, you might be more likely to overlook the symptoms of heart attacks in women.

2:28:25Traditionally, doctors and people themselves have overlooked it for that reason, because they've underestimated the sex differences. Mental health-wise, same deal. So even though autism is more common among boys than girls, there is a strong case that it's underdiagnosed in girls. And part of the reason for that is that it presents somewhat differently in girls. It's less likely, for instance, to involve repetitive behaviors. So people might not know, if they're not aware of that sex difference, they might overlook it in girls. And that means girls won't get the help that they need. And yeah, likewise with social problems.

2:29:02If we're looking at social problems like intimate partner abuse, if we assume that all intimate partner abuse only goes in one direction, like male to female, then we're going to underestimate the center, which sometimes goes in the other direction. The vast majority of it is bi-directional, right? At low levels it is, yeah. Sort of low levels, verbal abuse, pushing and shoving. And actually, in the West, there's even some data suggesting that verbal abuse might be more common women toward men. Other cultures, that's not the case. And it's more likely men to women. And when it comes to severe damn gender equality paradox indeed uh when it comes to severe aggression though even even in the west uh men do predominate but you know uh it's not a hundred percent and one of the harms of exaggerating sex differences uh so one of them is trying to push push people into um traditional gender roles and like if you just let people do what they want probably a majority are going to kind of gravitate in the direction in traditional directions but not everyone does.

2:30:13Because we don't have massive, massive sex differences, somewhat modest sex differences, there are always going to be some folks who are not going to want to go into the traditional directions. And my view, my let people be themselves view, would say, well, that's fine, just let them be themselves. It doesn't matter. But if you exaggerate and moralize sex differences, you're unlikely to think that. You're going to think, well, no, no, this is the way of nature. Any exceptions to the rule, that is by definition a problem, and we need to push people into those roles. What else? Other problems with exaggerating differences.

2:30:47If you exaggerate the frequency of cardiovascular health problems, you will say, well, you find them in men, not women. So that's another reason that you might overlook them in women. It doesn't occur to you that, okay, she's got these symptoms. What would that be? Well, it's not going to be cardiovascular problems because those are men's problems. Get the same thing with mental health problems, if you're really fixated on the fact that depression, for instance, is more common among women than men, you might overlook it in men because you're exaggerating the size of the sex difference. And a significant minority of people who suffer depression are men, about a third of cases are guys.

2:31:28So if you exaggerate that difference, you might not be on the lookout for that. Anxiety disorders as well, and social problems. So social problems like interpersonal violence, sexual harassment, if you exaggerate the extent of those, you are more likely to focus on just the cases where men are doing it to women. Those are the majority of the cases, but there are cases, the majority of extreme cases anyway, but you do find the reverse. The reverse is a problem as well, and it's a problem that we overlook if we exaggerate those sex differences. There's an irony there, though, which is that the sex difference in sexual harassment, sex difference in interpersonal, intimate partner abuse, the people who are most likely to exaggerate that and say it's all men, tend to be gender role progressives.

2:32:18So people who generally are trying to minimize and deny sex differences, in those cases, they actually, funnily enough, flip to the reverse and adhere to them and in just reverse it and massively exaggerate those differences. Fascinating. Steve, you're the best. I appreciate you, man. You've done a wonderful job with this book. Everyone should go and buy it. Billionaires of Sex Differences. What else do you want to plug? Could I plug my sub-state? So that's the thing I'm most excited about. Nature, Nurture, Nietzsche, newsletter. Dude, I'm a Steve Stewart Williams stan, bro. I mean, the April understood the universe is in the five books that everybody needs to read from my first reading list and had this one have been out it would have been in the second one uh yeah your your sub stack rules and everyone should go and check it out i love it my favorite thing that you do is the link fest yeah breakdowns once a month you just send like 40 or 50 different studies or insights that you found you're the best man i really appreciate you thank you so much for coming thank you chris thanks very much for for making this happen this is great i got you all right goodbye everyone okay later folks dude yes all right nailed it nailed it nailed it Fucking awesome.