Cordelia Fine, "Testosterone Rex: Myths of Sex, Science, and Society" (Norton, 2018)
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Welcome to the New Books Network.

Dr. Cordelia Fine is a professor of history and philosopher of science program at the University of Melbourne in Australia. Cordelia, welcome to New Books Network. Thank you very much for having me. Before we start the interview, can you just very briefly introduce yourself, your background, and how you became interested in this topic? Because you've published a series of books about the topic of sex and gender.

Yes. So my background, I started off as an undergraduate studying experimental psychology. Then I took a sidestep into criminology. Then I went back to my roots and did a PhD in psychology. And that was based, at least towards the end, in the Institute of Cognitive Neuroscience. So I was actually doing a partly neuropsychology degree there.

I then sort of sidestepped again and ended up working in philosophy for a number of years. And this is when I'd made a move from London where I did my PhD at UCL to move to philosophy at Monash University. And there I worked with philosophers primarily who were interested in issues of moral philosophy and what new evidence from particularly social psychology that was showing the

sort of the ways in which we were influenced by factors of which we're not aware, what kind of implications that had for our notion of ourselves as moral agents.

Following that, I actually ended up working in a business school for a number of years. So the Melbourne Business School, which is part of the University of Melbourne. And that was where the seeds of testosterone wrecks were kind of sown. So that might sound a little bit surprising because this particular book is not your sort of classic business school fair. But I had previously written Delusions of Gender, which is a book about the sort of

It was focused on the new neuroimaging technologies and the way that, you know, the sort of old ideas had been imported from the old technologies to the new technologies in ways that were sort of reinforcing these old gender stereotypes in ways that weren't really scientifically warranted, I was arguing.

And having finished that book, I started to notice that people were saying, okay, right, well, that's brains, but what about hormones? And in particular, testosterone was a hormone that I was hearing about again and again and again. So

So I think there was something about being in that business school environment. So, you know, of course, in business schools, there are a number of disciplines, including economics and finance. So there was a talk about, you know, why had the global financial crisis occurred? Was there too much testosterone on Wall Street?

and economists were getting interested in gender differences and they were drawing on ideas from evolutionary psychology to argue that men and women have evolved to be different, men have evolved to be more risk-taking, more status-seeking, more competitive, and this is where the sort of business school aspect of it comes in. This is why when we look even at our kind of apparently egalitarian Western countries that have had sex discrimination laws for, you know, 40, 50 years,

we still see more men at the top of organizations and we still see women investing more in family rather than career. So there was a lot of sort of circulation of these ideas that were sort of, you know, looking at this particular stories about evolution, stories about hormones to explain this sort of continuing disparities in social structure and

And I was kind of interested. So in a way, it was a complement to Delusions of Gender, which had focused a lot on this idea that men are thinkers and women are feelers. And then this was another piece of the puzzle, which was, and whatever field of endeavor women and men are interested in, men will be more motivated to try and reach the top.

That was a great explanation and now it makes more sense because you did write about that market crash in 2008 and Wall Street, so it makes sense that those ideas came from that business school maybe.

In your book, at the beginning of your book, you talk about terminology a little bit because this will come up a lot in the interview, I guess, and also it's in the book as well. Can you tell us just that clarification on the terminology between gender and sex that you use in the book? Yes. Well, those are simpler times back in 2017. I think, you know...

If I were to write that book again, that would be a more complicated section where I explain my use of terminology. But the way I was writing about it in the book was I was sort of drawing this sort of

I suppose perhaps now, old-fashioned distinction between biological sex and social gender. So I was using sex to refer to biological characteristics, and perhaps we'll get into that a little bit more later, and then gender to refer to the sort of masculine and feminine attributes that are ascribed to males and females in any particular society, as well as the sort of differential status that's

that's ascribed to males and females. I have to say now, a number of years later, I've become enamored of different ways of thinking about gender, but that's how I was using it in the book. So I wasn't using gender as a euphemism for sex, for instance, or for gender identity. Yeah.

And earlier you mentioned something about these stereotypes that there are specific types of jobs that are more suitable for men or more women, or men are more competitive compared to women. There is this whole evolutionary theory, especially evolutionary psychology as well, that is, I'm not going to make a judgment whether it's, there is a group of scientists, we agree with it of course, that come up with scientific explanation to say why this is the case, right?

What is your take on that? Do you agree with these ideas that, for example, there are competitive high-risk males and on the other hand, you're nurturing females, the way that evolution or evolution psychology explains it? Yeah, look, so this is sort of part of the whole testosterone rex explanation that I was looking to unpick in the book. So

it kind of has three aspects to it. It has a story about the past or evolutionary past and the effects of sexual selection on human males and females. Then it has a, it kind of makes a bunch of assumptions about what men and women are like here and now.

And the role of testosterone in, you know, from birth, in fact, from before birth in creating kind of masculine and feminine brains and minds. And then it has implications of what all that means for the future. So the kind of aspect to do with the past, which is what you're referring to, to do with this sort of evolutionary story, I mean, really what –

What I wanted to do in testosterone and accident was really fascinating to research. It was basically just to say, look, there was this sort of older, simpler story about sexual selection, creating risk-taking competitive males, you know, males being, you know, evolutionary biologists usually define sex in terms of what gametes you produce. So do you produce the small gametes or the large gametes?

And, basically, what I did in the first part of the book was to show how that rather simple story, which makes a link, a kind of chain of assumptions from small gametes to risk-taking in competition, large gametes to being more risk-averse, more nurturing, et cetera, less competitive, less promiscuous, et cetera, and to show how...

you know, that sort of simpler account of sexual selection has become complicated, unsettled. The very foundations of it have been sort of – have been challenged. So maybe if I – it would probably help if I just sort of set out the familial story. I mean, people probably will know about it already, but basically the idea is –

If you're the sex that invests more in reproduction, and this becomes particularly salient if you're a mammal, where they're on the female side, there's not just this larger egg, but there's also gestation, lactation, etc., then basically you're less available for mating. And so there are fewer of you around.

So you invest more, so it makes sense for you to be choosy about who you mate with. You've only got so many shots at reproducing, so you better pick the best possible mate. You can only produce so many offspring, so you better take care of those offspring. Whereas if you're a male, then you're going to be competing. You have this sort of minimum investment, which is rather low. It's just, you know, sperm.

So, you know, in theory, you can impregnate lots and lots of females. So it might be to your advantage to be very promiscuous, to compete with other males for mating opportunities, to sort of show off in front of other females that they choose you, and also to be quite quick to sort of abandon any offspring that you've produced in order to pursue other mating opportunities.

So this is an idea that stems really back from Darwin, who put forward his theory of sexual selection, which was sort of part of his larger theory of natural selection. And he observed that many species, it's the male that tends to compete for mating opportunities and that it's often the male

That has these sort of showy, extravagant characteristics, you know, whether that's the beautiful peacock tail, we have the drab little peahen, or, you know, it might be the songbird. It's the male songbird that sings some elaborate courtship song and the females kind of quiet.

So, so that's, that's where the idea started. And maybe I should pause now to let you ask questions if you, if you want, but, but that's, that's the sort of link between, you know, what gametes you produce, so your sex to how you behave.

in the world and society and with others. I think it's a perfect introduction for those who may not be aware of these evolutionary, the ideas of, you know, sex and gender from an evolutionary perspective. I'm more, I was more exposed to that through a,

So a friend of mine, we're doing this PhD in the same department, but I was looking at literature from a different perspective. We had an evolution psychology approach. We never agreed. We were always arguing. I had to read something. And I learned a lot from him, although I didn't agree with him, but I didn't have enough evidence to...

counter-argue, let's say. And that's how I was more drawn into these topics. I've done a number of podcasts on them as well. And what do you explain? Because you also talk about a very important evolutionary paper, I guess. It's Bateman Principle in Evolutionary Biology. And then you also...

you lay out the flaws in that theory, let's say, and then you also talk about female promiscuity or importance of resources ranks. So you look at it from a different perspective that other scholars have also talked about. I think it would be good if we could expand on Bateman's principle, shortcomings and the counter-arguments from a female perspective that we've rarely, let's say, we rarely bring into discussion. Right, yeah. Yeah.

No, good. So Darwin had his idea that we have these sort of passionate, arduous, competitive males and sort of coy, chaste females. And he did recognize that there were occasional reversals, but there were kind of the exceptions that prove the rule. But Darwin didn't really have a good explanation of why we appeared to see these patterns. And

And so it was really a British biologist called, or geneticist, Angus Bateman, who was working in the last century, and this work was done in the middle of the last century, that really kind of set the sexual selection theory going again. And he was interested in the idea that the reason you see this pattern is

because the challenge to be chosen is falling more strongly on males than females. And if that's the case, if that's the right explanation, then we should see a few things. So we should, first of all, we should see more reproductive variance in males. So more winners, more losers. So you're going to get like a small number of males who are like getting lots of mates and then some are getting none. Whereas for females, there should be a more even distribution. Like everyone does okay. Um,

And his second sort of hypothesis was that, or his second prediction was that

for males, the more females they mated with, the more reproductive success they would have. But for females, it wouldn't make any difference. And the reason being, the female just needs one sperm to get going and any extra sperm, it's no help to her. Whereas for a male, the further he can spread his seed, the more he'll do. So those are the two predictions. And

His studies were understood for many decades as showing that this was the case. So this was, I should say, it was not with humans, obviously. It was with Drosophila or fruit fly, which is like the favorite experimental animal.

But there were a few, I mean, this was taking place in the 1940s or 1950s. So, you know, we didn't, there wasn't a simple way of sort of genetically testing whose offspring were whose. So he had to, it was a quite clever experiment given the constraints of the time. He basically was breeding males and females who had different mutations. So they were kind of dominant and recessive genes. And basically what that meant was,

When you look at the offspring, you kind of look and go, well, what's wrong with this one? And having worked it out, you can try and infer, well, that must be the mum and that must be the dad. But it was a very imperfect way of doing the experiment. At best, it was available, you know, very clever, but obviously you would do it differently now and you could do it more accurately. And basically there were two biologists, Patricia Gowarty and I think Brian Snyder, who said, look,

biologists have been talking about this Bateman principle, this idea of greater reproductive variance and males having more mates the better for males and not for females. But this was a really old study. Let's go back and have a look at it with our modern statistical methods. And when they went back, they found that there was kind of a number of issues in the evidence itself. So one issue was that

there was a kind of overestimating of how many males, sorry, how many offspring males had had. So every offspring has a mother and a father, but it seemed like the males had produced more offspring than the females, which is a logical, you know, it's just an impossibility because every offspring, you can't have

an offspring that's produced by a male but not a female as well. There was obviously some bias in there, and that bias actually pushes towards inflating the reproductive variance that's being estimated for the male. That was one source of error. Another interesting aspect of this reanalysis, and this is just one of these strange little quirks of history of science in a way,

is that Bateman had run six series of experiments. Sorry, and this is getting really deep into the weeds, but this is just a nice example of how you have this sort of seeming fact, right? And then you have to go back and unpick all the layers and look at the assumptions that were made and the way things are analysed and how those assumptions just get passed on and on and on through the generations. Then it just takes a couple of scientists to go, hang on a minute, let's take another look. Okay, so Bateman had run six series of these experiments and

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He'd analyzed four of the series together, and then he analyzed the last two series together. And there wasn't an obvious reason why he'd separated them in that way. And in fact, this result, this important result that he got showing that it doesn't matter how many mates a female has, she doesn't do any better from multiple mating or promiscuity, if you want to call that.

That only applied to some of the theories that he looked at. When you looked at the other series, you actually did see an increase in reproductive success the more mates the female had. So Bateman had actually shown that females do get some kind of benefit from having multiple mates, for whatever reason that might be. And so when these contemporary biologists discovered

kind of pulled all the data together because there was no reason to separate them out, they actually concluded that taking into account all of these issues of the data, there wasn't really a firm statistical grounding for suggesting that there was something, that there was this claim that females don't benefit from multiple mating conditions.

And that was kind of interesting because in the sort of 21st century evolutionary biology, there had been this neglect of the possibility that females were looking for lots of different mates, right? Because you're like, why would you look for it? Because theoretically it just shouldn't happen. Like it's just a waste of time for a female. Why would she, if it doesn't help her reproductive success, why would she go through the risks and time and effort of doing that?

But in fact, as scientists, evolutionary biologists started to look for this phenomenon, they found that female promiscuity was actually rampant through the animal kingdom.

And they started to come up with ideas as to what kind of benefits would accrue to females from this promiscuity, from getting, sorry, I know some evolutionary biologists don't like using such a value-laden sort of human term to refer to females. So I'll try and stick to multiple matings. But yeah, so that was a kind of first sort of ripple through the foundations of Bateman's principle of

And, and as you know, as people continue to work on sexual selection theory, and in particular, just to start pay attention to what females were doing, instead of just assuming that they were there were these kind of boring, mediocre individuals who were

just achieved this very small success of getting some eager male to mate with them and then that was it. They started to notice, well, actually females are pretty interesting too. So they're mating with more mates than they strictly seem to need to get the sperm that they need. They're actually competing with each other.

that rank, status, situation, resources matter for female reproductive success. Yeah, so all of these sort of phenomena that wouldn't have been predicted by this sort of initial account began to come to light later.

And sort of both theoretically and empirically, they started to become this much more complicated story of what's going on in sexual selection, whereby it's not that you have this like standard sex role, male and female, and then the occasional exceptions to the rule. You just actually have a great deal of diversity, both across species,

but also within species. So when ecology changes or the social situation changes, you can flip from the males being the competitive ones to the females being the competitive ones, for instance. So there was just a lot more diversity and flexibility than that sort of initial foundational theory was.

starting with Bateman, would have led people to anticipate. I myself really like the history of science because there are lots of such examples that this theory comes up, it becomes like a seminal main theory. A lot of scientists just use it as a basis for their other theories, but then a couple of other people come and start retesting it and then they find flaws in that.

And this was a classic example. There's another thing. One of the book chapters that you have, it's called 100 Babies, and it refers to this hypothetical example in evolutionary psychology. Can you tell us what it refers to and why do you think this proposition is not a really accurate one and it's basically flawed? Yeah, so it comes from an evolutionary psychologist, David Schmidt,

So evolutionary psychologists, they're sometimes caricatured as saying men are just interested in casual sex and women are just interested in monogamy. Their views are more nuanced than that. So they say that both males and females, whether as individuals or across time, can be interested both in monogamy and in casual sex.

but they argue that men have evolved to have a sort of greater motivation to seek sexual variety. And, you know, that argument comes from, you know, what we've just been talking about, this sort of, you know, story about or this particular account of sex roles. And, you know, one of the sort of ways of making the argument has to do with, you know, the reproductive benefits to human men of having

of sleeping around, basically. So the claim was that, you know, comparing the reproductive success, you know, morals aside, that

If you're a man who indiscriminately slept with, had sex with 100 women in a year, then maybe you would produce 100 babies. Whereas if you're a monogamous man and you just had sex with that same woman, you know, you might have, if you're really lucky, you might have triplets or twins, but, you know, you probably have one baby if any. And I sort of, this is a very...

hugely optimistic view of how many babies you can actually reproduce from pursuing that kind of indiscriminate mating strategy. And this is really one of the criticisms that evolutionary biologists actually had made of this more simpler story. They're saying there was a sort of underestimation of the costs to males of reproduction. So there was this idea like you've just got this single tiny sperm

versus the egg, the nine months of pregnancy, or however many months of gestation, whichever mammal it is, the breastfeed, et cetera. And that really underestimated what was involved for the male. So first of all, it's not a single semen because you don't just shoot out one. There might be millions. It's

It's in this sort of rich fluid. You have to find the mates. You have to court them. It might be dangerous. You might have to provide some sort of nuttial gift. Okay, so all sorts of complications. And so evolutionary biologists have been finding, well, actually,

Actually, sex isn't always very cheap for males. Sometimes males are quite choosy. There are all these wonderful examples from the animal kingdom of males just not behaving in that stereotypical way. I think my favorite example, just before we get back to humans, is from a colleague of mine at the University of Melbourne who studies, Mark Elgar, who studies stick insects.

And, you know, he would say to me, you know, they're interested in his work, sort of interested in, you know, reproduction and so on. And so here we have these stick insects. And, you know, from my point of view, all they're doing is like lying around looking like sticks. And he would present them, these male stick insects with females every week. And, you know,

a large proportion of the time, they wouldn't even be troubled themselves to avail themselves of these mating opportunities, right? So here you have these males being quite selective and not as arduous as one might think. So to come back to men, I came across this wonderful article by a psychologist, I think she was from UCL, if I remember correctly, called Dorothy Einan. And she was sort of

challenging this very optimistic view of just how many babies a man could produce by engaging in casual sex. And so it was just with some very simple arithmetic. She said, imagine you've got a woman, she has sex once a week for 30 years, she produces nine children, which is a pretty good output, right? So you can do a simple calculation and you can work out that for each child that she produced, she has sex 173 times.

So that means that 172 times she's having sex and not producing a child. Well, some man is having sex with her.

you know, there are 172 times that a man's having sex and there's not a baby at the end of it. And so that starts to get you thinking about the fact that it's not quite as simple a story as you just find a female, you have sex, you know, nine months later, well done, you've racked up another successful baby on your reproductive success count, right? So when you actually start to do the calculations and you think about

First of all, what it would take to actually find 100 females to mate with, right? You've got to find one every two to three days. You've got to out-compete the other males who are also looking for females to mate with. You've got to, you know, you mate with them. You've only got another day or two then to find your next mate, keep up with your 100 women in 300-odd days, right?

You're having to maintain your status and resources as well so that you're a kind of desirable person for them to mate with.

And, you know, some of these females, they're not going to be in the fertile part of their menstrual cycle. They might generally be infertile. Lots of females are going to already be partnered. Some might be a bit too young, a bit too old. When you actually look at the chances of getting pregnant from a single act of coitus, it's actually sort of surprisingly low. Just to save sex, obviously. Yeah.

And when you actually look at the probability of, even if you could find those 100 women of producing 100 babies at the end of the year, I mean, it's vanishingly small. You know, you're like many, many, many, many, many more times more likely to be hit by a meteorite. So it's just not a plausible way of like, okay, in theory, you could do that, but it's so implausible until you start to get to

the part of human history where you can amass wealth and you can have harems, etc. But this is not a sort of regularity through human history, and particularly during the period when, according to evolutionary psychologists, we were sort of evolving our sort of psychological adaptations. So in fact, being monogamous and investing in that offspring

is actually not a bad way of having a kind of slow and steady reproductive output. And when you look at hunter-gatherer societies and you look at the sort of range of the number of children that women and men tend to produce, men are a little bit higher, it's true. But it's not a sort of vast difference. There's a bit of an overlap. It would be something like...

9 to 12 for women and 12 to 14 for men or something like that. So yeah, so it's this sort of idea of producing 100 babies from this promiscuous approach. I mean, that might be great if you're a fish and you're just spurting out. Everyone's just spurting out their gametes, right? But for humans, it's a bit more complicated. And part of the reason there's such a low success rate is that

to a much greater extent than any other animal, lesser primates, but even there, is that we're just having a lot of non-reproductive sex. We're much less efficient in our sexual behavior than many other species. There's another thing I want to ask you, and this is a tricky question, let's say, so I'm trying to...

ask it as carefully as I can. The idea of sex, and this is part of the book as well, that it's generally misused this idea, the word sex, because I think you complicate, not sorry, you problematize the way we use this term. Scientifically speaking, there's male and female, but you talk about sex as a system,

rather than a category. And then you say that there's a system considering all the genetics and all the other hormonal components and the effects it might have. It's more complex and it can't really be considered a binary. So can you tell us what is the complexity around it? And what do you mean by sex as a system, let's say, rather than as just a binary category? Yeah, yeah, good. Thank you. Look, so my thinking on this has been

Very strongly influenced. I mean, I want to credit the person who has really sort of shaped my thinking around this, which is the neuroscientist, Daphna Joel. And look, I draw on her idea of what she calls 3G sex in testosterone wrecks. And her 3Gs there are gonads, genitals and genes.

The idea being that in most humans, these are sort of either aligned in a male form or a female form. I don't know if that's the approach that I would take now, but that's what I draw on in the book. And Daphna's point, and she articulated this very nicely in an article for Feminism and Psychology, if I remember the journal correctly,

Her point is that, look, when it comes to sort of 3G sex, there are – okay, let me retrace. Part of the ambiguity of the word sex is that we use the same word sex to refer to quite related but distinct concepts. Okay.

So one use of the term sex, and this would be one that's favoured by evolutionary biologists, for example, would be sex is, you know, in humans and many other animals, it's a binary category that's defined by the kinds of gametes that the individual is born.

on the developmental pathway or have achieved the developmental pathway to produce. So there's male or female. And that kind of keys in to some extent to this idea of 3G sex. So in particular, the gonads are where the gametes are produced. So the testes will produce sperm and the ovaries will produce eggs. But we can also use the word sex to mean sex as a system.

And this is referring to the genes and hormones that create these two different developmental pathways, one to produce gametes, one to produce eggs.

And this can be quite varied across the animal kingdom. So, you know, we have, we tend to have XXXY for producing males and females, but there are lots of, there are different sex determination systems throughout the animal kingdom. You know, for turtles, it's temperature, for other birds, it's different sets of chromosomes. We also have sex as a system, which refers to whatever genes and hormones create these two different reproductive systems that

for males and for females. So that's pretty well articulated in humans and for many other species. But the point that Daphne Drell makes about sex as a system is that it's not these kind of binary discrete categories that we think of in terms of the two sex categories. So there are many different genes involved in the sort of

development of these different reproductive systems. There are, there, there are, you know, hormones like the androgens, estrogens, progesterone, et cetera, that are present in both male and female bodies and,

that they vary across time and the sort of period of, uh, the sort of life history of the individual. And there are periods when there aren't sex differences at all in some of these hormones. So testosterone is a really good example. So in prepubescence, with the exception of sort of a kind of brief postnatal period, as far as I am aware, um,

There's no sex differences in testosterone. Of course, there are post-pubescence and in a period prenatally. But the point is, is that here you've got what sometimes people refer to when they're talking about sex, you know, genes and hormones. And these are not sort of binary or non-overlapping sex.

And then sometimes people, when they're talking about sex, they're referring to the kind of phenotypic sex. So they're referring to the kind of physical differences between males and females. And then here again, you know, depending, you know, you have individuals who kind of defy that, you know, a sort of supposed pure binary. People who have differences of sexual development and,

And then, of course, there are many aspects of sex differences in the body that, again, are somewhat overlapping, you know, might be to do with height, breadth of shoulders, you know, facial hair, et cetera. So strength and things like that. So there's sex categories, sex as a system, and phenotypic sex, which can be quite broad. Some people even include the brain, right, as part of phenotypic sex.

And so sometimes these arguments, and I know this is not what you asked, but sometimes these arguments about sex binary, can sex be changed, etc.,

Part of the disagreement, I think not all of it, but part of the disagreement is because people are using the same word, sex, to actually refer to different things. But the reason this is important when it comes to the kinds of things that I'm talking about in testosterone wrecks, and this also feeds into some of the debates that are going on at the moment,

Some people have a strong preference for the gamete definition of sex, right? They say, look, the clearest definition that you get, the one that applies across all animal species is a gamete definition. It's the only one that makes sense. Okay, that's fine. That might be a really useful definition in some contexts, including trying to understand mating systems and so on.

But if you're a scientist trying to understand sex effects in brain and behavior, gametes, it doesn't get you very far because sperm and egg are not doing very much, so to speak. So then you're having to look at what are the kind of,

Sex is a system. So, you know, what is it that you're interested in? Is it some genetic effect? Is it hormonal effects? Or is it the kind of social effects of being male or female in a particular environment? That applies to non-human animals in a way that has until recently been relatively ignored. And of course, it certainly applies to us as humans as well.

I think this is the perfect explanation. And even when I sometimes argue with my friends, before reading your book, I think I use sex from that very, very generic sense without really taking notes of all these differences and complexities.

But I guess my excuse was that I have not really studied biology scientifically. I'm interested in the arguments about sex and gender. But I guess even those who have some of the biologists even that I've spoken with, they don't really make these distinctions clear. And they, again, just use sex from XX and XY chromosome perspective only. And in your explanation about...

about sex as a system. You mentioned brain, and I guess that's a perfect segue to my next question because, again, we start talking about this male brain or female brain and how they're wired differently to make men or women suitable for different types of tasks. So, again, I guess, and I'm guessing this is also more complex, and can you talk about that

And also the role of testosterone, as you mentioned, because again, that usually comes up in these myths that cause a high level of testosterone. That's how men think or how that's how women think. Can you elaborate on that point and debunk the myths, let's say? I know it's a very generic question, but if you can point us the right direction, because you have explained it beautifully in the book. Yeah. Thank you. Yeah.

Yeah, so there are so many things to say here, so I'm just trying to think about where to start. So one thing to say about sex in the brain, and here again I'm drawing on the work of Daphna Joel, and people are interested. She has a very accessible book called The Gender Mosaics, which I strongly recommend. But she was really interested in –

What she was seeing in animal research on sex differences, which is that, and obviously in animal research, you can look much more closely at what's going on in the brain than you can with humans. And so she would see that, you know, there might be some sex difference in some aspects of brain cells in the rat. You know, females, dendrites are bushier. Okay, it doesn't really matter what that means.

But then if the rats have undergone 15 minutes of stress, then the sex difference actually reverses. So what was male typical in the sort of stress-free environment and the stress-free rats becomes female typical in the rats that have been stressed or whatever it might be. And then there might be a different kind of pattern when it comes to a different aspect of the brain and how it changes in interaction with the environment.

And so Daphne Joel's point was that, you know, people have been very interested in looking at sex differences of brain and they've often documented sex differences in the brain. And there's just no doubt that there are sex differences in animal brains and in human brains. But people hadn't been thinking about whether those kind of add up in a consistent way or if they mix up because of these interactions with the environment.

And one way that Daphne Joel and philosopher of biology, John Dupre, and I talked about it in an article that we co-authored for Trends in Cognitive Sciences, was drawing on this kind of nice distinction from the philosopher of biology, Gillian Barker.

who, you know, we all agree that, you know, biology and environment interacts, right? So we're all interactionists, but there are different, she points out there are different kinds of interaction, right?

So one kind of interaction would be what you might call a conservative interaction. So it might be that there's a kind of, to put it a bit colloquially, there's a kind of intended outcome for the brain, for example. And if you want to try and modify that, you're going to see that same outcome across a very wide range of environments. And you'd only see a deviation from that

in really extreme or unusual or kind of atypical environments. So that would be a kind of form of conservative interactionism.

Then there's what she would call, what she calls additive interactionism. So that would be, well, the environment has an influence. So, you know, let's say, you know, the amygdala, if you're raised in an environment with lots of threat, then your amygdala might be overactive. And if you're in a sort of very calm, peaceful environment, it's less interactive. And there's just this sort of linear relationship.

But there's a third kind of interactionism which she calls radical interactionism, which is exactly what Daphna Joel is describing, that what you see can be in males versus females, and that's the biological aspect of things, can be opposite. The sex differences can be eliminated or even reversed depending on the environmental condition. So it's this form of kind of radical interactionism.

And I find that really also both Daphna Joel's insights but also Gillian Barker's are very helpful because it helps us get away from this sort of tedious like, oh, well, genes environment, you know, like, yes, okay. But how do they interact and what does it mean? So Daphna has done really interesting and influential work basically showing that we see people

Her prediction was that because of these sex environment interactions,

We shouldn't see kind of male brains and female brains. Yes, there are sex differences, but we shouldn't see sort of just, you know, distinct male brains and female brains. We also won't see like a continuum, which is what we might get from the kind of additive interaction of like the most male brains, the most female brain. Everyone's sort of on a spectrum along that with more females obviously on the female side, more males on the male side. But then we'll see mixtures of very heterogeneous populations that

of sort of mixtures of brains with male typical and female typical features. And so in what was a very kind of influential and controversial article, I would say, she looked at large databases of brains that had many measures of brain structure to sort of test this gender mosaic idea. And she did get quite a lot of pushback from that work,

from particular from people arguing that she was setting her criteria of what a male brain and what a female brain is. Her criteria were too demanding. But since then she's done, she's been doing, you know, with co-authors really interesting work using machine learning to show, for example, that if you used what's called unsupervised machine learning,

And so you just say to this algorithm, you know, find two types of brains in this group. They won't pick out male and female brains, for instance. Or if you say find six clusters of

you'll find similar numbers of males and females in many of the clusters, and there might be just a few rare clusters that are mostly male or mostly female. So that's really interesting work, kind of challenging this idea of male brains and female brains without saying, well, there aren't any sex differences in the brain at all because there are. But this complexity is what you would expect given these sort of sex environment interactions.

That was already a very long answer, but you did also ask me about testosterone, but maybe I'll take a pause here and let you jump in. That was a great explanation. I had heard of that book before reading about Gender Mosaic, because I was a bit lazy to go and read the book, but I'm really keen to read that book as well.

Yes. And I wanted also to ask about the Cestron because that's, we've been obsessed with that. If you have it, there are certain things you can do. If you don't have it, there are certain things you can't do. So it's good thing to have batting, not to have. And,

I just wonder, and you know, the title of your book, The System of Wrecks, which is debunking of the smith. But why are we so obsessed with that? Is it because there are other elements in the body? But I guess this is an easier one to measure maybe. But why are we so obsessed with that? And why is that story more complex? Excuse me. Yes, interesting question. Yeah.

why it's had so much attention. I mean, you know, testosterone is one of the androgens that maketh the man, right? So science would be very interested in what separates men and males from women and females. And there's...

I think my intuition, I don't have hard data on this, but my intuition is that as more women have entered these kind of fields of behavioral endocrinology and evolutionary science, there has been sort of more interest in studying other hormones that are more associated with females, even though everyone has all of them.

And I suppose it's also true that testosterone can have quite dramatic effects in some non-human animals as well. So it's not as if it sort of came out of nowhere. But I think what's interesting about the human case is just in a sense what, you know, empirically there's been so much effort put into trying to

forge these empirical links between testosterone and masculinity. And it's been just remarkably unsuccessful as an empirical endeavor. So in Testosterone Rex, I look at a number of different ways that scientists have tried to just sort of look at these links, as have others, incidentally.

So one way is to look at people who have differences of sexual development and most commonly a population of genetically female girls who are exposed to atypically high androgens in utero.

The interest being, you know, are they more masculine in girlhood, in womanhood? And the claim being that any evidence that they are is a sign of that's the effects of testosterone on the prenatally in organizing the brain in a more masculine fashion. So that's been one area of research. Yeah.

Another area has been, you know, to look for correlations between markers of prenatal testosterone and latest masculine behavior. So looking at digit ratio, that again has been, you know, not hugely successful yet.

And another way, of course, is to look at circulating levels of testosterone. So, of course, you know, post-pubescence, healthy males have much higher levels of testosterone than females. And to look at correlations between those levels of testosterone and masculine behavior or to intervene and give people, you know, a big whopping dose of testosterone to see what happens.

And so, you know, there are lots of different ways of looking at the question and the kinds of trappings of masculinity that people have been interested in.

are things like physical aggression, forms of risk-taking, and with the girls with congenital adrenal hyperplasia. This is a kind of interesting one because initially the research, and this is work from Rebecca Jordan Young in her book Brainstorm, she points out that initially they were interested in all kinds of things that they thought that higher testosterone in utero would bring about, like higher intelligence, sexist time.

more dominant behaviour, for example, those results didn't pan out. So instead what the researchers have looked for are kind of gender role behaviours. So what kind of...

What kind of toys you like to play with or what kind of activities that you want to do. But of course, the problem there, and this is something that I've raised in more than one book and others have raised, it just keeps getting ignored in this empirical research program.

is that these gender roles are very culturally bound. They're treated as if they're like the peacock tail, you know, like every male peacock will have this peacock tail, right? That's the trapping of masculinity if you're a peacock. And things like playing with cars versus cars

playing with an ironing set are treated like these sort of timeless universal trappings of masculinity and femininity without really interrogating that assumption. So just to continue a little more on some of the problems with that research is that

Because I think this is the area of research that is seen as providing the strongest evidence that testosterone is doing something prenatally that is setting us on different developmental paths and setting us towards different roles in society. So it's a really important one to focus on. And part of the problem with this research is that the girls who are being studied, the

And again, this is the work of Rebecca Jordan Young who points out there are lots of things going on in the lives of these girls beyond what happened to them prenatally. So they might be born with masculinized genitalia.

They might, although this is changing, they may be undergoing multiple surgeries to quote-unquote correct their genitalia. They might be getting lots of questions about their gender and their sexuality. They may be aware there will be issues with penile-vaginal sex in the future. There are concerns about fertility, etc. And then there's this belief that they will be masculinized

They physically, there are kind of morphological effects of having the condition that mean that they don't necessarily conform to sort of Western ideals of feminine beauty, etc. So there are all sorts of confounding factors or complexities of how they're developing. Yeah.

And it might just be that for whatever reason, either to do with these sort of contextual factors or something that's more to do with some kind of effective testosterone on gender identity, who knows, they don't actually just seem to be as invested in gender norms as girls on average without the condition. So in more recent research from the lab of Melissa Hines at Cambridge University, they

They look to see if girls with congenital adrenal hyperplasia would kind of pay attention to cues about what's for them as girls. So you can do these studies where you show boys and girls, you know, like an orange balloon and a silver balloon. So they're not gendered in any way, but you say to them,

This silver balloon is for girls and this orange balloon is for boys or vice versa, right? And what you find is that typically girls and boys will be, when they're given the choice, they'll choose the balloon that they've been told is for them as a girl or for a boy. So very sensitive to gender norms.

But they found that the girls with congenital adrenal hyperplasia, they could remember what was, what had been labeled as for boys and what had been labeled for girls, but it didn't influence their decision. So they're in a sense, they're like, screw your gender norms. I'll choose what I want. Right. And so that provides a sort of alternative explanation of the fact that many studies do in fact show that these girls are more likely to play with boy toys, for instance, and

So that's always been interpreted as showing that there's something going on in the brain that makes these girls more interested in cars, trucks, blocks, whatever is in the sample of boys' toys.

But an alternative explanation is just that for some reason that we don't quite understand, but to do with a sort of different developmental trajectory, they're not as gender conformist as the sort of average girl or the average boy, which is a really interesting alternative explanation. So, yeah.

To sort of wind back a little bit, you asked me about these attempts to find links between testosterone and male and female brains and masculinity and femininity. As I said, this is usually taken as the kind of like, well, what about that? You know, here's our explanation of why we have, you know, more female nurses and more male engineers, right?

And look, we don't really know exactly what's going on. Maybe there is something of that kind going on, but there's just, there is a good deal of uncertainty in the data. And here I'm going to just take a little step back and say that when we start to think about

What's special about humans compared to other animals? It actually makes sense that we would have this flexibility, that we would get gender through this sensitivity to norms and an ability to pick up roles rather than through testosterone or some other components of sex.

us to be interested in particular kinds of things. And I say that because humans are kind of these super cooperators. This is, you know, this is superpower if you want to call it that. And in order to cooperate, we have to be able in all the many different environments that we cooperate in, we have to be able to imitate others, to, to be sensitive to norms, to internalize norms, to enforce norms and others and,

to develop a kind of social identity and to develop a sense of ourself as a member of that particular group. So I've been quite influenced in thinking about this by the work of a philosopher of mine called Tad Zawinski, who wrote a book called Mind Shaping. And he talks about, you know, the many different ways that what he calls mind shaping processes that enable

enable humans to come together and sort of relatively seamlessly cooperate. So, you know, you and I were having this interview and we know the norms and we know how we're supposed to behave and, you know, multiply that through, you know, all the other many ways in which humans cooperate in order to survive and reproduce. And you say we have these

you know, these distinctively human socio-cognitive capacities. And we can see the kind of acquisition of gender norms and gender roles as fitting right into that pattern. So to me, that interpretation of what's going on with the girls with congenital adrenal hyperplasia

It's not a kind of grasping at straws alternative explanation because I can't bear the idea that the hormones might be involved. I'm totally open to that idea. But I actually think that this is at least as plausible an explanation of what's going on.

And I have just a couple of more questions. There's this idea of gender socialization in your book that I really loved. What do you mean by gender socialization and what is its role in developing our social behavior? Excuse me, yeah.

Yeah, I think I was just, I mean, I was using gender socialization in a sort of very, from a psychologist's point of view, a very ordinary kind of way. So the ways in which gender norms are, there's a sort of external regulation in terms of gender norms, but there's also this internalizing of gender norms. So there's a sort of self-socialization, which I think often gets misinterpreted

So, you know, particularly in kind of egalitarian circles, people will say, like, I never forced pink on my daughters, but, you know, they just wanted to wear the pink frilly dress. And they think because they're not pushing the pink frilly dresses or whatever it must be, it must be something internal, right?

But, you know, children are developing a gender identity, a sense of themselves as, you know, a boy or a girl, you know, from about the age of, or an explicit one, from the age of about two. And they're already learning what it means in a particular culture to be a boy, to be a girl. And as I mentioned before, through this idea of mind shaping, we kind of internalize some of these norms so that children understand

maybe sort of self-directed to fit in with, you know, what it is that boys and girls are supposed to do. So that's why when you tell them the orange balloon is for girls, if you're a girl, you're more likely to choose that than the silver balloon, for instance. But I think one of the really interesting things that I learned when I was researching this book was

And again, this comes from the work of Daphna Jewell in a paper with a neuroscientist who focuses on sex differences, Margaret McCarthy, is they're talking about that sex, there are many routes by which sex can get its work done. So if we see a difference in brain and behavior, whether it's in animals or particularly if it's in animals, but also sometimes when it's in humans,

we assume that this kind of a direct effect of either sex-related genes or sex-related hormones on the brain and therefore on behavior.

But sex has other effects, right? So sex, you know, it creates different genitalia. It can create, you know, in rats, it can result in the urine of baby male rats smelling differently to the urine of baby female rats.

It can create, you know, secondary sexual characteristics that other animals in the environment then respond to, right? So sex can have these effects on the body or morphology in some kinds of way. And then that influences the kinds of experiences or the way that others interact with that individual. And that's a form of indirect effects of sex. And, you know,

That work of getting to whatever developmental outcome you want, those indirect effects, as long as you're going to have that environment generation after generation, that's going to work just as well. So if you're a rat and you're going to survive, you're going to have a mother.

So if you've got a mother that likes the smell of testosterone in urine and will lick the males more, that's actually been shown to have an effect on brain development, helping to masculinize brain development. And that in turn is then linked with sexual behavior, right? So it's a thing

Things that you want to see, these adaptations you want to see passed on generation after generation, we tend to think, oh, that's so important. It must be passed on the genes. Well, not necessarily because some things get passed on, inherited,

uh, externally to the genes. Like you're always going to have a mother, for example, or sexual imprinting as another example. So you're always going to grow up in a, um, in a, you know, a little, if you're a sheep, they're going to be other sheep around you. And that's can provide the input to know, okay, that's the kind of species that I need to mate with. If you run a school experiment and you have a little lamb being reared instead by goats, um,

the male lamb will grow up to be sexually attracted to goats. From an evolutionary point of view, that seems like, "God, if you want to be reproductively successful, you better have sex with the right species. You better be sexually attracted to the right species. That's so important. Surely it must be built into the genes." Well, actually, it's not. The environment is a kind of developmental resource.

So that's just examples with non-human animals. And of course, when it comes to ourselves, you know, we create culture and we pass it on with modification. And part of that culture is very heavily gendered. So

Part of the way that we can get the work done of creating gender roles is through gendered culture and the capacities to socially learn and inquire those cultural traits. And so that helps to explain both the persistence of gender roles over time, but also the immense flexibility and diversity that we see in gender across human societies, across time and place.

Before we come to the end of this interview, I'm keen to know if there is any other project or book you're working on, anything we should expect sometime soon? Yes. So I actually have a third book coming out in March 2025 for UK and Australia and May in North America.

It's called Patriarchy Inc. And in a sense, it's like the, I'm thinking of it as a third in the trilogy that started with Delusions of Gender, which was about brains. Then, you know, Testosterone Rex was about evolution and hormones. And Patriarchy Inc. has developed those ideas, but it's also targeting more directly some of these claims that

about gender equality in work. So I have two targets in the book. One is this kind of

And one is this idea that's quite similar to what we've been talking about today, which is this idea that we're different but equal. So yes, there are lots of disparities in occupations, in leadership, in gender, earning gaps, etc. But it's because men and women have evolved to be different because of our biology. And it's just to do with choice and markets and

But I'm also targeting this idea that the way to achieve gender equality, and I see this as the other kind of prominent way of thinking about gender equality in our kind of current society,

narratives is by focusing on the business case. So if we just get leaders to get excited by how much money they can make from having more women in their organizations, particularly leadership roles, then we'll find our way to gender equality. So I have these kind of dual targets in the book. But the book does go –

to connect a bit more with this interview, the book does go more deeply into these different ideas about evolutionary science and humans and really pointing out that although sometimes evolutionary psychologists seem to suggest that rejecting evolutionary psychology is just a rejection of the idea that evolution has acted on the human mind,

There are many other, in my view, more plausible candidates for thinking about our evolutionary history and what it is that we've actually inherited and that guides our behavior. So, yes, that's the recently completed big project. Which publisher is it coming from?

In the UK, it's Atlantic and Alan and Unwin in Australia and then Norton in North America. Great. Well, I certainly hope to be able to talk to you about this, your new book next year once it's published and I've had a chance to read it. That would be great. Yeah, I'll definitely touch base with you to talk about that book as well.

Dr. Cordelia Fine, thank you very much for taking the time to speak with us. The book we just discussed was Testosterone Rex, Myths of Science, Sex Science and Society, published in 2017. Thank you very much for your time. Thank you. It's been a great interview. Really appreciate it. Thank you.