The Nazi Lies Podcast

Mike Isaacson: I don’t know if my brain is gay, but it definitely fucks.

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Mike: Welcome back to another episode of The Nazi Lies Podcast. Subscribe to our Patreon to get on The Nazi Lies Podcast Discord where we host our new book club. More at the end of the show. Anyway. with us today is Dr. Rebecca Jordan-Young, a science studies scholar and professor at Barnard College. Her book, Brain Storm: The Flaws in the Science of Sex Differences, is a critical exploration of brain organization theory and its conclusions about the differences in so-called male and female brains. Thanks for joining us, Dr. Jordan-Young.

Rebecca Jordan-Young: Thanks for having me.

Mike: So, I want to begin with the question you ask at the end of your book to kind of foreground our conversation. So at the end of your book you ask, “What good is a science that doesn’t tell us anything new?” So before we get into the science of brain gender, how should science be conducted and why?

Rebecca: That's a great question. I believe that the best science comes out of curiosity. An example of what that does for you- I mean, scientific curiosity means that you're studying things that are– you’re genuinely pursuing questions that you don't already think that you understand. You want to know more and understand it. You're not just trying to prove a point that you already knew, because that's a whole different form of, you know, argumentation and evidence. So I was certainly taught, and I think all scientists are taught this, not everybody follows it, but I was taught that you have to test a specific hypothesis – what you think is true about the world.

But every time you have your hypothesis, you have to have something called the null hypothesis. And a null hypothesis is the direct contradiction of your hypothesis. And when you set up a scientific experiment, you need to give both your hypothesis and the null hypothesis an equal chance of being supported by the evidence that you collect. What that means is, you have to be very clear. Ahead of time, you have to actually say, "Okay, here's my null hypothesis. When I'm collecting my data, am I already loading the dice in a way that there's no way I could collect the evidence that that might be true?"

So you're obligated to not set yourself up to just already be right all the time, you have to build in the possibility of real surprise and even disappointment. And that's really tricky. You know, there's a lot riding on being correct with your hunches and moving forward. But you have to– Good science means that you build in an equal chance that you're going to get disappointed. I'll just also say that, you know, if everybody doing work in an area shares many of the same assumptions, it can be very hard to come up with a good null hypothesis, and that's something that I think you see in brain organisation theory.

So sometimes it takes people coming from outside the usual crowd. It might mean people that aren't all trained by the same people or at the same institutions; it might mean somebody who has some different training than what everybody who's been doing the work does, so you bring in the influence of a different discipline. And that's one reason why diversifying science can be so useful by shaking up assumptions, and then there's a better chance that that's going to happen.

Mike: Yeah, and Patricia Hill Collins talks about that in “Learning from the Outsider Within,” I think. Right?

Rebecca: Exactly.

Mike: So, most of our listeners, and probably most people in general, have never heard of brain organization theory, but in all likelihood they take its conclusions as Science with a capital S. So before we get into the myths of sex differences, what is brain organization theory?

Rebecca: Brain organisation theory is an idea that got traction in the middle of the 20th century. And the idea is very simply that there is such a thing as a male brain and a female brain and that, in fact, not just that there is but (and here's the clue to why the science has been problematic) that the theory says there must be such thing as a male brain and a female brain because we're a species that reproduces heterosexually. And if you have male genitalia and female genitalia, you have to have a male brain and a female brain to know how to use them properly to reproduce, and by 'know how to use them properly', that begins to, you know, like mushrooms into this huge explosive set of even quite abstract social behaviours.

So the idea, generally, is that this must be the case. And then a lot of the studies are like, "Okay, how is that the case? What specifically is different? How do we know that?" The theory supports some very, very common stereotypes and assumptions, like “women are more oriented to people and not very good with technical systems or mechanics,” that “men are naturally risk takers and women are more cautious,” that “men don't do domestic work because they're naturally less interested in it than women are,” instead of, because of a combination of gender socialisation, gender expectations, and social power. I mean, typically, the people that do repetitive grunt work are the people with less social power.

So a lot of the broad patterns that we see in male and female behaviour, brain organisation theory says that is because of something innate and inherent inside of people, inside the different brains of men and women, and not because of history and social power and the great force of multiple cultures over millennia.

Mike: Right. The big point I that I took away from the book was that it had to do a lot with prenatal hormones, right?

Rebecca: Oh, so sorry. [laughs] I'm sorry. It's been so long since I was like thinking in the nitty-gritty, absolutely. So the way it's supposed to work mechanistically is this. With brain organisation theory, the idea is that same process of hormone exposures that shapes that genitalia, also shapes brains so that they go in two binary, you know, incommensurable directions. So in particular, the idea is that testosterone, if a developing fetus is exposed at key periods in growth to a certain level of testosterone, that they're going to develop a male-typical brain, and they're going to have this whole range of male typical traits. Whereas the idea is that the female or feminine direction of brain development is just the default. It's literally described as the passive development, which from a strictly biological point of view, is an oxymoron. There's no such thing as passive development.

So that's the idea. Early hormone exposures make concrete, physical structural changes in the brain and those changes in the brain create permanent patterns of behaviour, of desires, of skills, that either properly belong to males or to females.

Mike: Okay. And like I said before, it's kind of treated as just science, there's this not really any-- when it comes to pop culture, there's not really much in the way of questioning its conclusions. So what kind of brain organisation theory do people generally believe?

Rebecca: Some of the conclusions are, you know, I said some of this earlier; the notion that-- here's some really big ones that I didn't mention. The idea that women have greater verbal abilities and facility. That the ability to use words and communicate is going to be naturally more developed in women, whereas mathematical and mechanical skills are going to be better in men and boys. The idea that being oriented towards physical prowess is a masculine thing. Even some things that are maybe not held as such broad stereotypes, things like the idea that men are more visual or the idea of sex being something that men and boys naturally want much more whereas women and girls are less driven by our own desires, but are much more receptive and that that's just natural and normal to be less autonomous in our sexuality.

Another very clear and deep assumption that's really at the heart of all of this is that heterosexuality is the natural normal proper channel of sexual desire and that if somebody isn't both completely gender typical, fitting expectations and norms of gender, and strictly heterosexual, that something went awry at some point. There was something unusual in brain development. And you can say 'unusual' now, some years ago they would have said 'pathological', but the idea that heterosexuality is the normal path is also very much at the heart of this.

Mike: I want to actually get into more of that with the kind of the assumptions that are built into it. What are some of the other assumptions that are kind of peeking around the corner?

Rebecca: The assumptions, first of all, I hinted at this when we started and I said that the theory came out of really a conclusion that male and female brains must be different, there must be these two types of brains. And that is attached also to an assumption that gender norms and patterns are both binary, that it's kind of a package deal of sex, meaning the body, gender, meaning the ways that people fit into masculinity and femininity, and sexuality, who people want as partners, how they partner, what their sexual and reproductive lives look like.

So this idea also that gender norms and patterns, what counts as masculine or feminine behaviour or traits are universal. They're roughly similar across place and time. So, you know, this flies very much in the face of actual historical evidence, which we could talk about if you want, but that's the assumption.

Another assumption is that brains are more or less dimorphic, there's a male type, a female type. If you know somebody's gender, you can predict a lot about their skills, their aptitudes, their preferences. That's also absolutely contrary to the data that we have, but that's one of the big assumptions.

A third one, you know, this is not just a theory, it's like a whole area of assumptions. Some of the assumptions are about deep history, like early human evolution. The idea that at the dawn of human history, the typical core social form was a heterosexual nuclear family with a division of labour that looks like Victorian England or 1950s US. You know? [Mike laughs]

Again, it's not just fantastical, it's contrary to so much of the always-emerging evidence from the archaeological record about how humans actually lived. So there you go, it's not just a gender binary, but it's heterosexual at its core. And those assumptions are, you know, it's kind of like putting the blinders on and not allowing in evidence from other fields. And by other fields, I mean history, archaeology... so even, as I'm saying, even other fields of science.

Mike: Okay, so you’ve studied all of the over 300 brain organization theory articles spanning the first four decades of its existence before it exploded into popularity and then a sizeable chunk of the studies since then.

Rebecca: Right.

Mike: Can you tell us what a typical brain organization theory-driven study looks like?

Rebecca: Yeah, there are a couple of different forms. The most common forms include, they're kind of two groupings. One is studies that start with some group of people that are known to have unusual hormone exposures during their early development. These are people typically with a range of clinical conditions.

Earlier, some of those studies tended to be of people whose mothers were given synthetic steroids during pregnancy before some of the risks of giving steroids during pregnancy were understood, so they had these unusual hormone exposures.

But others are people who let's say they have an adrenal condition that causes them to make very high levels of so-called androgens, hormones that create physically masculinizing traits as one example. And so if there is a genetic or chromosomal female, so an XX fetus, that gets very high levels of testosterone in early development with a condition, there's a condition called congenital adrenal hyperplasia, those women and girls with that have been studied just over and over and over again as one group. So again, it's like one whole group.

Another subset of those are girls and women whose mothers took Diethylstilbestrol, which is actually a synthetic estrogen, but because hormones in fact are not binary, this synthetic oestrogen has some properties in animal studies where they've decided that actually it's what they would call masculinizing. There have been studies to look at people with early Diethylstilbestrol exposures.

A second whole group of study, instead of looking at people who were known to have unusual hormone exposures, there are people who are, we could say atypical-- not fitting stereotypes of sex, gender, sexuality in their adult life-- and looking backwards in time to say, "Can we figure out any way that there's other evidence that these people with unusual gender or unusual sexuality also had unusual prenatal hormone exposures?"

So those studies typically take, let's say, gay men and compare to straight men and look at the length of their fingers, you know, to say, "Okay, there is some evidence from animals that suggests that the relative length of one finger versus another is affected by steroids in development. Do these two groups that are different on sexuality also have these physical patterns?"

I mean, they've looked at so many different aspects of the body. [laughs] There are brain organization studies that compared straight men and gay men on genital size and development. There have been lots of studies that look at lesbians and straight women and, for example, test them to see, "Do they have a difference in spatial ability across the two groups?" So what you can probably pick up immediately if you're listening to this is that all of these studies, you couldn't really control the variables a whole lot. These are studies that are not tightly controlled experiments, because you can't actually do tightly controlled experiments on this theory in human beings.

I hope that gives you some sense. I mean, the studies are kind of all over the place, but I've given you a sense of the two main kinds.

Mike: Yeah, I know. There was the case control studies and the–

Rebecca: Right. Right. Just to be clear, the case control, those are the studies that basically look at the groups that have what these people would call an unusual outcome. So gay people versus straight people, or trans people versus cisgender people. Those would be case control, where you have this outcome and you look backwards in time to see is there any evidence that they had a different, you know, input early in development?

And the other kind of study, we would call a cohort study, where you know that there's one group that has an atypical input, different hormones than is typical early in development, and then you follow them over time and compare them to people who presumably had typical hormones?

Mike: Before we continue, you kind of mentioned this. You've been calling what we typically call sex hormones, “steroids.” Can you talk about a little why you don't call them sex hormones?

Rebecca: Yeah, thank you for asking that. This is something I've worked on a lot, and I want to give a little, you know, hat tip to a couple of other people. I'm want to give a hat tip to, certainly, Anne Fausto-Sterling and also to Nelly Oudshoorn, who's a Dutch historian. The reason I don't call them sex hormones is that that idea of sex hormones actually was out there way before we knew anything at all about the actual substances, and that idea of sex hormones has really kind of deformed the knowledge that we have about what steroids are and how they operate in the body. So this idea that there's such a thing as male hormones and female hormones, there's so much inaccuracy connected to that.

First of all, all of us have the same exact hormones. We have them in different typical ratios, so there are very substantial average differences in what are typically thought of as sex hormones. Average females and average males have different ratios. But it's a real mistake to think, for example, that "Well, estrogen is the female sex hormone." In fact, estrogen is crucial for so many male typical functions as well as for functions that are just human and that have nothing to do with sex and reproduction.

The same thing is true of testosterone. Testosterone is crucial for bone density and muscle development. And testosterone and estrogen work together in both of those things. It doesn't make any sense to think of muscle tone as a male typical trait because without functional muscle tone, nobody could stand up, nobody could walk, we couldn't use our hands and arms or legs. So it's like these are species-typical traits that we need these steroids for. And there's a lot of individual variation, a lot of variation within and among males and females on all of them. When we think of them as sex hormones, I think it distorts what we can know about them.

I'm going to give you a really good example. One of my favourite examples is in the 1970s, this group at Rockefeller University led by a scientist named Bruce McEwen was studying rats, and they were studying what they thought of as male typical reproductive behaviour. So you know, mounting and so on. But they were also studying physical development, like the development of male genital and reproductive tract.

And around that time, they were understanding the way that steroids actually chemically transform in the body. So there's a process called steroidogenesis, where one steroid meets an enzyme and it turns into something else. And they understood that estrogen is produced when testosterone meets this enzyme, aromatase. So you can say that estrogen is a product of testosterone. Well, they wondered what would happen if you blocked that conversion of testosterone to estrogen? How would that affect the physical development and behaviour in these rats?

And what they found out was, if they blocked the testosterone from turning into estrogen, many of the male typical traits never appeared. What that means is that many so-called male typical traits actually develop under the direct influence of estrogen. That's just one tiny tip of the iceberg but once you start down that path, then you begin to realise that calling estrogen the female sex hormone, makes no sense whatsoever because they just don't divide in that way.

Likewise, I'll stop with this one, but another one of my favourite facts to undermine the idea of sex hormones is when you ask people, "What's the most abundant steroid hormone in women's bodies?" What do you think the usual answer is?

Mike: Probably estrogen, right?

Rebecca: Right. Do you know what the real answer is?

Mike: Not sure, actually.

Rebecca: Testosterone.

Mike: Really?

Rebecca: This confuses people. It throws them for a loop. They think I can't be right, but in fact, it is the truth. It is also true that men on average have way more testosterone than women do. But women actually have more circulating testosterone than we have estrogen.

So by what logic would you call estrogen the female sex hormone, right? It's because you already decided ahead of time that the whole thing must be split into some kind of binary system, and it must be understood through the logic of everything getting assigned to male/female.

It actually just doesn't work that way. Testosterone and oestrogen are really crucial for all of us. There are big average differences, but it's not helpful to split it up by male and female. So the reason I don't use that language is that it actually actively blocks curiosity. It blocks that thing that I said is crucial for good science, and there are many cases where not being able to absorb that evidence has actually slowed us down in scientific progress.

Mike: So back to the book, you talk about symmetry as a necessary condition for scientific veracity. And when we say symmetry, we’re talking about the correspondence between what these studies claim and various other things. And so you talk about symmetry at three levels: symmetry between a given study’s measurements and the abstract thing it’s describing; symmetry between a given study and other studies that are similar; and then symmetry between a given study’s use of terminology and how terms are commonly understood. We’ll talk about how the studies you researched measured up, but first why are these kinds of symmetries important?

Rebecca: Well, think about it this way. I mean, it's really about making sure that you're comparing apples to apples when you're building up the whole scientific field. So let's say that I'm doing a study, and I say that I'm interested in sexual orientation. But then what I do is I go out and I observe all the people on a city street over the course of a week, and I write down the people that look gay to me versus the people that don't. And I watch, you know, what stores they go into. And then I draw assumptions about where the gay people shop and when straight people shop.

Anybody could come along and say, "Hey, wait a minute. How do I know that you actually know who's gay and who's not? And on what basis are you judging who's gay or who's not?" Obviously, how I look at people is a very poor measure of something like sexual orientation. That's a really good blunt description of how some of the studies go off the rails on the first measure. And they're not quite that bad, but some of them come pretty darn close when it comes to not really measuring what they say they're measuring.

For example, I might say that we're looking at, you know, we're comparing gay men to straight men, but we actually never asked the people that we called straight what their sexual orientation was. All we did was gathered one group of men who we didn't ask but we thought that they looked and seemed "normal" based on some reason-- quote, normal in air quotes there-- and then we compared them to this group of men who we decided were gay. Well, that's a terrible measure. That's why that matters.

Another, when I say the studies "the same thing" should be looking at the same kind of outcomes, one of the best examples of that is how studies that make conclusions about how female typical or more stereotypically feminine sexuality develops, really made an incredible flip flop in the middle of when these studies were done on what counted as typical feminine forms of sexuality.

One of the most amazing examples is that in the early studies, if a woman reported that she masturbated literally ever, she would be coded as having masculinized sexuality. Or if a woman said, like in an interview– These studies, a lot of them did clinical interviews and then they coded them after the fact. So in a clinical interview if somebody asked about a woman's sexual arousal, and she actually described the way her own body, the way her own genitals felt and responded, that would be coded as masculine. Because the idea at that point was that women's sexuality was much more about romance and love and it was much less directed towards, you know, genital contact and activity. Well fast forward to 20 years later, and if a woman said that she didn't have genital arousal, she would be coded as having undeveloped feminine response. And so she would be taken out of that group. You can't put those studies together and then say they're all measuring the same thing and feminine sexuality.

And with the last symmetry principle, a good example of that where the question is: if I say that I'm studying sexual orientation, or I'm studying homosexuality and heterosexuality and how they develop, what I'm looking at should bear some relationship to the way we understand those terms out in common parlance in the world. But some of the studies use these very strange, very selective, very narrow measures of who gets in those groups in a way that just is misleading in the long run.

So people might read about a study that says, you know, that gay men have this feminised digit ratio. But then when you go in, and you figure out who they said was gay in those studies, you're like, "Oh, actually, that's really not who we think of when we're talking about that and when people are, you know, say organising for their rights in the world, they're just trying to go about their lives."

So there's a lot of responsibility when you're doing this kind of work to make sure that, among other things, to make sure that if you're studying something where the categories have enormous social importance, you should be defining that in a way that has some relevance to the real world.

Mike: Yeah. And just like kind of where to draw the line too. I mean, you gave a diagram in your book where you had the Kinsey scale and showed a study basically dividing between straight and gay at every point on the scale.

Rebecca: Yeah, exactly. One of the things I say in the book is, you know, Kinsey scale is actually not an answer. It doesn't give you a set of answers. It's a series of questions about, you know, like on a scale of zero to seven or zero to six, how much you are attracted to or have sexual contact or relationships with people of your same sex versus the other sex. And there's no– Kinsey– Kinsey was against the idea of dividing people into binary groups. So he didn't give some kind of cut point where over here, you're gay, over here, you're straight.

And different people doing this research have chosen every single place along that line. So in some studies, you have to be 100%, attracted only to people of your own gender or sex and only ever had sex with people of your own gender or sex, or otherwise you don't count as gay.

And in some other studies, it's completely the opposite. As long as you've ever had sex or thought about even fantasised about someone of your same sex one time, you will not be counted as straight. You might be counted, even in some of those studies, as homosexual or gay instead of being bisexual.

So there's just no standard in there and obviously, if you put all those studies into the same mix, it's incoherent. You can't do that.

Mike: Right. And so generally, how do the studies measure up in terms of symmetry?

Rebecca: Well, [laughs] from what I've said so far, you should have a pretty good idea. It's a pretty big hot mess. One of the things that I thought of, at one point when writing the book, is people are right, there is a ton of data out there. And there are a ton of so-called positive findings, like they're all these correlations. But if you were to try to actually build a structure out of it, where everything solidly built on something that was a proper foundation to the next thing, you couldn't possibly build a structure, what you get is a giant pile of rubble. You get this big meaningless data pile that actually contradicts itself as much as it supports itself.

Mike: So back to those common brain organization theory conclusions people believe, why are those conclusions at least questionable if not flatly wrong?

Rebecca: Well, for one thing, they're contradicted by more consistent data that we have from other places. So for example, the idea that girls and women naturally, because of deep evolutionary pressures that have shaped our early hormone exposures and therefore shape our brains in a certain way, that we naturally have poorer mathematic ability than males cannot hold up when you look at the actual mathematical ability of males and females and you look in particular at cross cultural studies that show there are plenty of places or plenty of subgroups where girls and women outperform boys and men on quite a few mathematic measures. If you look at the way that the typical American sex difference in mathematics performance has shrunk basically to nothing over the past 40 years, where it was pretty substantial, but it's changed a lot.

Some people still talk about, you know, things like there are certain forms of spatial relations, like this skill called 3D mental rotation and how that's still very different between males and females. Actually, again, that depends on what group you're testing. There are some subgroups where that's absolutely not the case, but there's no reason to think that subgroups of men and women have these different inputs.

Another thing is that with like 3D mental rotation, very, very short training on something like a target video game can actually eliminate the sex difference. And if that is the case, then you can't really claim that there is this permanent, underlying, innate sex difference. It's much more plausible that the observed differences that we see come from different experiences in postnatal development.

So things like the way young children are handled and touched and the way they're encouraged to move in the world. Things like sports involvement. Things like encouraging games that involve throwing the ball, for example, with boys.

There is a lot of evidence both from neuroscience and from cross cultural research that has stronger and more consistent findings than the brain organization findings do. And I could go on with many, many other examples.

The second category of data and reason why I would say, aside from just the fact that studies look really messy and they don't actually point in the same direction, we kind of shouldn't expect them to point in the same direction. If you look, as I mentioned before, about history and archaeology, with brain organization theory the idea is like, the sexual drive is innately a masculine thing, and girls and women are receptive to that, but they're not driven by sexual desire, they're driven by a desire for offspring. So this has been a very common Western assumption for a long time. But if you actually back away from that assumption as being just true, and you think, who is that supposed to apply to? And you look at the way norms and belief, whether it's showing up in science or in literature and poetry, for one thing, you'll see that that's always only been the norm for bourgeois white women, you know upper middle class white men. That's the expectation of being asexual, and the idea that somehow working class women, women of color, etc, were sexual in a way that upper class white women weren't. That should clue you in [laughs] that there is something wrong with that theory that it's not about some kind of evolutionary-driven innate process.

Then if you just want to stick with like, European mythology, you go back to the early modern period. And the idea was that women were sexually insatiable and that men had a much greater ability to control themselves because of greater rationality. And so it was like the sexually voracious appetite of women was something to look out for.

So the point here is, if you actually pay attention to history, pay attention to cross cultural analysis, or just class analysis or look at scientific racism and typical just cultural racism to see where the norms are, how they're limited, who they attached to, who they don't, both the science falls apart and the story falls apart. [laughs] And that's a lot to fall apart.

Mike: So returning again to the question you ask at the end of your book, “What good is a science that doesn’t teach us anything new?” What direction has research on these topics–prenatal hormones, sex and gender differences, studies of queer populations– What directions has this research gone, and where do you think it still can go?

Rebecca: Well, to be honest, there are other people that could answer this question better because I got bored with brain organization theory. And it just it keeps on churning out. There's a lot of reason for that. I think there's a lot of investment in the theory, quite literally monetary investment. People's whole careers, their labs, they've trained people in it, you know? There's a lot of reason to keep doing this.

But there's also a lot of social investment in the idea of binary indifference. There's a way in which studies that are moving on in this track haven't kept my close attention. Plus it generates at such a rate, you know, I would have to spend my entire life and career if I wanted to stay on top of that. So all of that's kind of a caveat.

At the same time, I do know a few trends. One trend is to try to kind of salvage the theory by complicating it and saying, "Okay, well, maybe it's not just testosterone exposure per se that creates this trait, but it's testosterone exposure under this condition with also either high cortisol or low cortisol or something." I mean, that's often true of other forms of studies that look at the effect of steroid hormones on adult behaviour. And that's kind of where a lot of this research has gone, there isn't as much focus on the prenatal hormone stuff as there used to be for a lot of reasons. But there is still a kind of relentlessness to this.

At the same time, there are a lot of really interesting young scientists coming up who are saying, "Okay, brain organization theory is not where it's at. Let's instead start thinking about, you know, what do we actually know?"

One more promising direction where some research on hormones and behaviour has gone is-- A great example is the researcher Sarah van Anders, a psychologist up in Canada, who has a really interesting project that is genuinely not binary. She is actually interested in doing a few things. One of the most interesting things is to not assume that traits or people should be all just split up into male and female all the time. She is coming up with more interesting measures of how people describe themselves, how they describe the actions that they do. And then, she's also looking at hormones in a way that is more accurate in terms of what we empirically have seen specific hormones’ effects to be.

As an example, she is working very hard at breaking down the assumption that testosterone is a masculine molecule. And she's looking at the kinds of effects that testosterone has been associated with, in a way that doesn't attach them to maleness or masculinity at the outset. And one example is, you know, forms of aggression and protection.

So if you think about the idea, one of the constant underlying ideas, that males are more aggressive and males across the animal kingdom is this idea: males are more aggressive. But there's also this other piece of empirical evidence that one of the most consistent, if not the most consistent, situation in which you're going to see a strong physical aggressive response, is when the offspring of a female animal is threatened.

So in fact, there is this really, really strong pattern of physical aggressive response. And so she's trying to, for example, think about the idea that aggression is all one thing, break it instead into defence and attack. And also that nurturing or parenting is all one thing, like in those cases, at this point, you can't take nurturing or take parenting behaviour and oppose it to aggression, because here they're deeply coupled.

So she's doing this really interesting theoretical work that's driving the way that she is, in my opinion, a lot careful with the actual measures that she uses. So that, to me, is one of the most promising directions out there. There are other promising directions but I think that's probably enough.

Mike: Well, Dr. Jordan-Young, thank you so much for coming on The Nazi Lies Podcast to talk to us about the science of sex differences. The book again is Brain Storm out from Harvard University Press. Thanks again.

Rebecca: Thank you so much.

Mike: If you liked what you heard and want to support The Nazi Lies Podcast, consider becoming a Patreon subscriber. Patrons get access to early episodes, access to our Discord, and a shipment of Nazi Lies merch. Join us on Discord for our weekly book club where we read the books of our upcoming guests. Get access to the show’s calendar, updates on the topics we’re looking to cover, and I dunno, what else do you do on Discord? Come hang out, and who knows? I may even ask your question on the show.

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