How Testosterone Makes Men, Men
Episode Stats
Summary
Dr. Carol Hooven is a Harvard biologist and the author of Tea: The Story of Testosterone, the Hormone That Dominates and Divides Us. In this episode, Dr. Hooven explains the arguments made against testosterone s influence on shaping men into men, and why she doesn t think they hold up. She then impacts the argument for how testosterone does function as the driving force in sex differences, and how it fundamentally shapes the bodies and minds of males.
Transcript
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Brett McKay here, and welcome to another edition of the Art of Manliness podcast.
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What creates the differences between the sexes?
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Now, many would point to culture, and my guest today would agree that culture certainly shapes
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us, but she'd also argue that at the core of the divergence of the sexes, and in particular
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of how men think and behave, is one powerful hormone, testosterone.
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Her name is Dr. Carol Hooven, and she's a Harvard biologist and the author of Tea, the Story
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of Testosterone, the Hormone That Dominates and Divides Us.
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Today on the show, Carol explains the arguments that are made against testosterone's influence
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on shaping men into men, and why she doesn't think they hold water.
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She then impacts the argument for how testosterone does function as the driving force in sex differences,
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and how it fundamentally shapes the bodies and minds of males.
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We delve into where tea is made, how much of it men have compared to women, and what historical
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cases of castration tell us about the centrality of testosterone in male development.
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We then discuss how tea shapes males starting in the womb and going into puberty and beyond
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before turning to its influence in athletic performance, and we enter a conversation with
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Carol's impassioned plea for celebrating what's great about men.
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After the show's over, check out our show notes at aom.is slash tea.
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So you've got a book called Tea, the Story of Testosterone, the Hormone That Dominates
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So you have spent your career studying the physiological and psychological effects of testosterone on
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I'll just start by saying when I graduated from college, I had no idea what I wanted to
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And then I decided that I wanted to go work with Richard Wrangham, who I know you've had
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And the reason I wanted to do that is because I had been taking classes and reading books
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and just trying to, and traveling and trying to figure out what I really wanted to do when
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And I read this book by Richard Wrangham called Demonic Males.
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And I had really been focusing in on understanding human behavior and I'd gotten really interested
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Then I discovered genetics and evolution and got really interested in that.
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And then I read Richard's book, which used research on non-human primates, primarily chimps,
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as a way to understand the evolutionary and genetic origins of human behavior, particularly
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And I thought that was something that I might be able to actually do, especially because
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And so I quit my job and applied to the Harvard graduate program and got rejected because I had
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And then I really bugged Richard and some other people in the department.
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And eventually, because I was persistent and enthusiastic, not because I had any special
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expertise, I have to say, Richard gave me an opportunity to go out to Uganda and study
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I ended up getting evacuated because there was a lot of really awful violence and political
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upheaval around Uganda in that region of Africa at the time.
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But long story short, it was spending eight months in the jungle with chimpanzees surrounded
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by a lot of actual human aggression and violence that got me really interested ultimately in
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testosterone because anyone who goes and spends time with chimps can see that the sex differences
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in the chimpanzees in so many ways mirror sex differences in humans, just in these very
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broad patterns of status and hierarchy obsession among the males competing largely for food and
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the right to have sex with the females who are in estrus, who can get pregnant.
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There's a lot of status obsession in the males.
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They're also capable, you know, like humans are, of being kind and nurturing and warm and
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And the females, on the other hand, I never saw, although it does happen, I never saw any instances
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And so that was just this very pronounced sex difference where there was a lot of nurturing
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and caregiving among the females, just much more peaceful overall on, you know, all of this
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is on average and they don't have any human culture.
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So there was nobody who was going to be able to convince me after that experience that these
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similar patterns of sex differences in humans are primarily due to human culture.
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The way they're expressed, you know, is heavily dependent on human culture, but the evolutionary
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and genetic origins are, you know, in us, we're born that way.
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And so that's why I got interested in testosterone because there's no more powerful way of explaining
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human sex differences, which are, you know, male behavior in particular is a really important
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One of the goals of your book is to push back some of these popular arguments out there
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that testosterone really doesn't influence differences between the sexes.
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I mean, can you briefly summarize the arguments against T's influences on sex differences?
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Like if it's not testosterone, what are they saying is causing the sex differences?
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I've been asked this before and I admit I do find it challenging because, but, but it's
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And I try to do this in the book, which is to entertain the best argument from the opposition.
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So most critics, except for the most extreme ones will acknowledge that the physical differences
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basically from the neck down are due to testosterone.
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So it really, you have to be kind of a nut job to deny that male size and strength overall,
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although there are nut jobs who are getting a lot of press, unfortunately, but that's just
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really would be incredibly far-fetched to try to deny the science that testosterone at least
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explains the secondary sex differences in humans.
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So that's height, muscle mass, you know, fat distribution, body hair, those kinds of
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So most critics will acknowledge that testosterone is responsible for those physical differences.
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More reasonable critics, and I think, you know, this can play a really useful role in
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the science of testosterone and sex differences.
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Most other critics deny that testosterone has any important effects on the brain and thus behavior,
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and that it is not ultimately sort of the most powerful driving force in those sex differences
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So the largest sex differences that exist, and this is not my view, this is fact, I'm
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not talking about the cause, I'm just talking about the observation, are in sexual psychology
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So those are huge, consistent with non-human animals.
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We see them across ages, not the sex part, but across cultures, you know, they're just
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And so those sex differences exist, but the question is, does testosterone influence the
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brain and behavior in ways that promote increased physical aggression in males and increased desire
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So those are the biggest sex differences, and those are the ones I really focus on in the
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book because there's so much clear evidence that testosterone in the early developmental
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period, like around, you know, prenatally and directly postnatally, and then in puberty
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and beyond, that those differences in exposure to that hormone and how it acts coordinates
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the body, the physical adaptations of size and strength with psychological adaptations that
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enable male animals, including humans, to take advantage of their larger body size and the
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fact that they have sperm in a penis, that they have to be motivated to want to get that
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And to do that, especially over human evolutionary history, there had to be physical competition
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with other males for status or for the resources they need to acquire high status, which enable,
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Now it's, a lot of that is money and professional status.
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But doing all of that increases the chances that males will be able to have a higher number
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I mean, and there's different strategies that males can use, and we can get into that.
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So it might not be an increased number of sex partners, but it might be using one's body
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and having the psychology to want to use one's body or even just one's sort of competitiveness
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That could result in the acquisition of a high quality mate, where if you mate with that
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single female for life, you could do very well reproductively.
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It doesn't mean that you have to have 10 kids, but it means you have to acquire that mate and
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So the adaptation is not the male desire necessarily for children.
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It's the desire to either partner with one or a few mates and be a good partner or play
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There's many different strategies, but sorry, this is a long answer.
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But the idea is that testosterone coordinates the psychological adaptations with the physical
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And I should just get back to the critics because I've gotten off the topic here.
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But the critics are, to me, bizarrely denying that they'll accept that testosterone acts
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on the body, but then are denying that it acts on the brain because they want to assert and
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they do assert that because we live in a gendered society, the default assumption should be that
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the sex differences that we observe are due to social and cultural influences.
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But this just doesn't make sense from a scientific and evolutionary point of view.
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The default assumption is that we are like all of these other animals where testosterone does
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It's not a coincidence that it does the same thing in humans.
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It's just that our culture can exacerbate those differences.
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They can minimize, the culture can minimize or kind of enlarge those differences or just
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Why do you think the critics are so reluctant to embrace the fact that T influences not just
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Yeah, I think it's based on fear, which should not be playing a role in science and our efforts
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So even if the fear was true, if the fear was based in reality, so suppose the fear is that,
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well, if men are dominant to women and have power, commit rape, cheat on their wives, if that's
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because of something in their genes, if that's because their genes code for high levels of
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testosterone and testosterone promotes these behaviors, the fear might be, well, then there's
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Then we're stuck with bad male behavior and it justifies bad male behavior because it's
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That's called the naturalistic fallacy, by the way.
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You know, anyone can see in two seconds that there's plenty of things that are natural,
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And there's also plenty of evidence that we are definitely, that's biological, the idea of
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biological determinism, that if something is in our genes, it's immutable and we're stuck
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And all you have to do is look around the world at different cultures and different societies
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and see what the differences in, say, the rates of murder are.
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Because males commit across the world about 95 to 98% of all murders.
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But in some cultures, the sex difference in the murder rate and the murder rate itself
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And I always use Singapore as an example because it's extremely safe.
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People, especially women, can walk around feeling safe because the sexual assault is incredibly
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You know, physical aggression committed by males in general is extremely low.
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And that's because of their culture and harsh penalties for those crimes.
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And we know that there are examples on the other end.
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Like I was just talking to a grad student in my department who is from India and he was,
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and I, you know, know the data on India, but sexual assault is rampant because it hasn't
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been taken seriously in India by the government there and the, you know, you can get away with
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And so men, if you can get away with it, men are going to do it and they do.
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So the idea is that genes and testosterone sort of lower the bar for the expression of
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those behaviors in the right environmental circumstances.
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But that doesn't mean that the environment can't shape heavily the expression of those
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So males are definitely more inclined to those behaviors, but we know that there's all kinds
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of things we can do to tamp down the expression of those behaviors.
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And that's clear from just even looking across cultures or even across time and how we've
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Our genes haven't changed, but the laws have and that social norms have.
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I think everyone has a general idea what it is.
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It's a male, all male and females have testosterone, but males have more testosterone.
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And like, what are the difference in testosterone levels in men and women?
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So testosterone, first of all, in adulthood, males have anywhere in puberty, males can have
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10 to 30 times the level of testosterone as women.
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But in Western kind of well-fed populations, it's about 10, males have about 10 to 20 times
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And there's no overlap in testosterone levels in healthy, normal populations of men and women.
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And so in men, about 95% of testosterone comes from the testes and the rest of it comes from
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mostly from the adrenal gland and there's some other sources.
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So it can, most of it comes from the testes and then can enter the brain, but it can also
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be made de novo in neurons, which is really interesting.
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And I should just, and so in females, about half is made, you know, these very, very low
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And then the rest is made in the adrenal glands and in fat cells.
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So also, and I should just say, estrogen comes from testosterone.
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So testosterone is converted into estrogen in males and females, and males also make estrogen.
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And males who have more body fat are going to have more of the enzyme, which is called
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aromatase, that converts testosterone into estrogen.
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So men who have a high level of adiposity can start to develop some feminine features like
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And that's because the estrogen levels can really rise due to this high activity of this
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So in females, estrogen can come from conversion of testosterone in various tissues and from
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precursors to testosterone that are produced in the adrenal gland that can then also be
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And I should just say that testosterone is an androgen and there are different androgens
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Testosterone is the main one, but there are other ones like dihydrotestosterone, which is
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And all the androgens interact with what's the androgen receptor and like a key in a lock
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And the androgen receptor is present in many, many tissues, again, also in our nervous system
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And what's interesting is that the sex steroids, which are estrogen, progesterone, testosterone,
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DHT, can all, because they're steroids, because they're fatty molecules, they're lipophilic,
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They can just cross the blood-brain barrier, they can get right through cell membranes,
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inside cells, and they affect gene transcription once they're inside cells.
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So they're very, very powerful, and they can go everywhere and have these long-term systemic
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I think it's interesting to note that our knowledge of testosterone is relatively new.
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It wasn't until like the 1920s that scientists are able to actually pin down testosterone, the
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hormone, but before that, scientists, people, humanity had a hunch that the testicles were
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And there's some interesting, I guess we can call them natural experiments that happened
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throughout human history where we were able to figure out there's something going on with
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And one of them is this really interesting thing that's in Italy, church choirs would
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castrate young boys, basically, they're called the castrati.
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Like, what did we learn about testosterone from that?
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I do talk a lot about castration in the book over the ages and in different cultures, and
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And it was all gross because I did get, it's not funny.
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I did get into the procedure and there's also eunuchs in imperial China and the way that
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But most of the history of castration, so if we just start with the castrati in, say, 18th
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century Italy, these are, this, what happened was there was a lot of poverty and there were
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opportunities for kids who were pre-pubertal, who were singers to gain, you know, fame and
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I mean, some of them could gain great fame and fortune, but even if they didn't have great
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fame and fortune, they could have some fortune at least and help out their families.
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And so every year, thousands of young boys were castrated in the hopes of sort of making it
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So a lot of them died and most of them did not make it and had to live lives of a eunuch.
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So the, what happens is if a kid, a boy is castrated prior to puberty, so most of the people
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listening are men who have gone through puberty and you know exactly what happens when you
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go through puberty to your body, to your psychology, to your voice, and sometimes to your hair.
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You know, some people start going bald fairly soon after puberty, but a eunuch never goes bald.
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And so what happens is if you remove the testes prior to puberty, and again, yes, this is before
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anything was known about testosterone, but there were these predictable changes where the period
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So it's, and the reason is that in puberty, it is actually rising testosterone that is converted
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primarily into estrogen, even in boys, that causes the growth of the long bones and that when it
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plateaus towards the end of puberty, that causes the growth plates in the long bones to seal.
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And that is why growth, the height spurt stops at the end of puberty.
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It's actually because of estrogen coming from testosterone, even in boys.
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But the point is, if you remove the testes, you never have that testosterone increase during
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And that growth hormone generated childhood growth.
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Like I have a 12 year old boy, he's still in that sort of growth hormone period.
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He's transitioning now to testosterone is going to be taking over.
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So you get this longer period of childhood growth and the castrated men can end up to be very
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tall because they don't have that testosterone peak where growth ends.
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So they can be very tall and they don't get those secondary sex characteristics that most
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of your listeners will have developed during puberty.
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And that's the, that's the big point is that the voice doesn't deepen.
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And they retain a sort of high, they retain a soprano singing voice, but they have a much
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They have, so they have a powerful soprano voice, more powerful than a female soprano voice
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So they needed men basically to fill those parts in the choirs.
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But of course, what happens is these men have almost no libido and of course they have no
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So it's, it, that is one of the ways, that's one of the sources of information that castration,
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So it's something about the testicles is necessary for typical male libido.
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And this was also known because there was lots of castration experiments on animals and animals
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would be castrated to reduce aggression, to reduce libido for various reasons, to, you know,
00:23:11.560
generate certain kinds of meat, like from a chicken, a castrated chicken has, is, has a
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And so it's been known for ages that castration of male animals reduces muscle mass, reduces
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and eliminates libido and aggression in some cases.
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So there's, was a long, deep knowledge about the testicles and, and the necessity of the
00:23:40.980
testicles for sort of typical male behavior, but testosterone itself was not isolated until
00:23:48.040
And so that took a long time because we've known about this since like the fourth century
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And yeah, so it, it took until the early 20th century to really identify testosterone and
00:24:03.560
So let's talk about like how testosterone makes boys, boys and men, men.
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And I think oftentimes we think, oh, testosterone only has an effect on a male during puberty.
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Because that's when you have this huge spike, but you talk about it's that in the influence
00:24:22.120
Like what happens to a fetus when it's exposed to testosterone?
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So that's super important that, that prenatal and directly postnatal period.
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We don't know as much about what testosterone is doing in little boys, little boy babies when
00:24:41.940
But we can talk a little bit about that later, but we know a lot about what it's doing in
00:24:48.500
And I should just say that the way that little humans or conceptuses, which are just that embryo,
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the very early embryo actually doesn't become male or female because of testosterone.
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It takes on male and female characteristics because of testosterone, but the determination
00:25:14.360
of male and female is dependent upon the presence of the Y chromosome and the gene on the Y chromosome
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that is sex determining region of the Y called sex determining region of the Y chromosome or
00:25:27.940
So if you have the Y chromosome and you have, and it has an intact SRY gene, which almost male, you know,
00:25:38.060
That is what causes the undifferentiated gonads to differentiate into testes.
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So before six weeks, the embryo is not identifiable as male or female.
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You know, you could look at the chromosomes, but there are no structures or physical differences
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It's when that gene is expressed that it goes on to cause that tissue, those undifferentiated
00:26:05.060
gonads to differentiate in the testes direction rather than the ovaries direction.
00:26:11.020
So once that happens, it just takes a couple of weeks for the testes to start pumping out
00:26:16.400
So like I was pregnant with a boy and it was just bizarre to know that he was in there with
00:26:22.260
his little testicles in my body that his little balls are making testosterone that, and that
00:26:29.560
testosterone is what was necessary for guiding his body and to promote the development of all
00:26:38.400
the male reproductive structures and physiology.
00:26:41.100
So his scrotum, his penis, his prostate, his vas deferens, all that stuff is due to the
00:26:51.660
And testosterone can do that because, like I said before, it acts on his genes that females
00:27:02.920
It's just that they don't have testosterone to cause the genes to be expressed in a way that
00:27:08.720
grows and maintains the male reproductive structures.
00:27:11.520
So the little fetus has testes that produce a lot of testosterone, and that's what is responsible
00:27:18.780
for the development of the male reproductive structures and male reproductive function that
00:27:26.000
But at the same time, evolution has done this amazing thing where testosterone at the same
00:27:32.940
time prenatally, as it's working on the body to masculinize it, it goes into the brain because
00:27:40.260
I'm just going to say it knows that this is an animal that needs to reproduce in a way
00:27:49.240
Like this animal has to compete basically for female mating opportunities and is going to be
00:27:55.060
So this animal is going to, as a little kid, need to do more rough and tumble play, for instance.
00:28:01.320
And females might have to practice nurturing behavior.
00:28:05.600
So females don't have exposure to testosterone in utero, or they have very typically very, very
00:28:11.960
Males will have high levels of, very high levels of testosterone in utero that masculinize the
00:28:17.800
body and the brain so that the brain can take advantage of the male body and shape that animal for
00:28:23.960
male reproductive strategies, you know, which are different than what females need because females
00:28:28.820
males need to use their bodies to grow their offsprings and feed their offspring, sorry,
00:28:34.840
And males don't use their bodies to grow the offspring.
00:28:39.360
They use their bodies to compete for the right to make, to have a female do the work for them,
00:28:50.400
Sorry, it's a, actually, it's a short-term rise.
00:28:54.100
It's a three-month increase in testosterone shortly after birth.
00:28:59.180
That seems to be very important physically, again, and probably neurologically, but we
00:29:07.700
But there's some hints that it might have to do, might further masculinize behavior and
00:29:12.260
have something to do with penis development and could have something to do with ultimately
00:29:19.200
But there's not a huge amount of work on that yet.
00:29:23.200
So, okay, basically, there's kind of like a mini puberty.
00:29:28.380
We're going to take a quick break for your word from our sponsors.
00:29:35.280
So basically, this prenatal exposure to testosterone, is it kind of laying the groundwork, like the
00:29:45.160
So the framework that scientists use to talk about this is called the organizational
00:29:54.440
And this is actually really important because people think all you have to do is shoot up.
00:29:59.740
And this happens, obviously, in like trans men or people who transition their gender.
00:30:08.660
They'll block their own hormones and take the hormones of the opposite sex.
00:30:12.200
So, for instance, if a female transitions to live as a male and takes male levels of
00:30:18.300
testosterone, that testosterone that she's taking as an adult is acting on her brain in
00:30:26.740
a way that's different from how it would act on a male brain.
00:30:30.400
Because a male brain has been met, the neural structures are permanently masculinized.
00:30:38.340
These aren't like huge differences in structures in the brain.
00:30:41.260
These are widespread, small effects on like cell death and synaptic and connections between
00:30:50.360
So these are small effects that seem to have small changes that seem to have important
00:30:56.980
So the brain is masculinized in boys prenatally.
00:31:00.780
And then in adulthood, when testosterone goes up in puberty, that testosterone is acting on
00:31:07.020
those previously masculinized neural structures so that if testosterone goes up in adulthood,
00:31:14.440
say in a female whose brain has not been masculinized prenatally, it's going to have a different effect
00:31:20.180
because it's not acting on previously masculinized structures.
00:31:24.520
And this is hard to study in humans, but it's very clear in non-human animals that you cannot
00:31:31.400
activate typical male sexual and aggressive behavior in female animals whose brains have
00:31:39.540
not been masculinized prenatally, if that makes sense.
00:31:46.440
And so, okay, this prenatal exposure to testosterone is what gives boys their boyish behavior.
00:31:59.440
Yeah, so there's a lot of rough and tumble play.
00:32:01.520
I think I've heard boys, this is generally tend to be more object oriented as opposed to
00:32:08.940
And what's interesting, like gender differences in toy preferences.
00:32:11.720
You see this even in chimps, they'll give chimps, you know, a toy and the female girl
00:32:18.760
chimps will like play with maybe like a doll, but like the boys will somehow turn it into
00:32:26.560
I mean, the primate toy studies are less, they're interesting, but I-
00:32:34.260
They're less convincing to me than the rough and tumble play.
00:32:41.280
Yeah, you can look at all these, just look at, take mammals and it's not even confined
00:32:45.340
to mammals, but you could look at chimps, you can look at rats, you can look at a huge
00:32:51.260
variety of animals and you look at the juveniles and there are clear sex differences in play
00:32:58.260
that are parallel in many ways to what we see in humans where the male, the little boys,
00:33:04.760
say in chimps or in rats are tackling each other.
00:33:09.400
They're, you know, what they're doing is practicing physical competition for status
00:33:15.520
So they have to practice their reproductive skills, their survival and reproductive skills.
00:33:22.460
It has to be fun or else they wouldn't do it and they wouldn't get the practice, but they
00:33:26.280
like that heavy physical play more than females do.
00:33:31.580
And in humans, we see the exact same patterns and in non-human animals, you can easily manipulate
00:33:39.460
the expression of that behavior by simply suppressing testosterone exposure in boys or increasing
00:33:45.740
prenatal testosterone exposure in females and female juveniles in non-human animals.
00:33:50.900
It looks like it's entirely due to prenatal testosterone exposure.
00:33:56.800
And then in humans, first of all, we have a very large and cross-culturally consistent
00:34:00.960
sex difference where boys like to play physically.
00:34:04.080
You know, I've, again, I have a son, he has friends who are female.
00:34:08.740
I don't see girls getting together in groups and jumping all over each other for hours.
00:34:14.380
Like boys will tend, you know, on average, not everyone does this and there's overlap
00:34:19.260
in these complex behaviors, but these are broad patterns.
00:34:22.880
And there's a suggestion in humans that it's also apparently, of course, a cultural influences,
00:34:29.180
but that testosterone is the primary driver because we know in girls who have different
00:34:35.740
conditions, especially congenital adrenal hyperplasia that result in their exposure prenatally to
00:34:45.220
So it's not as high as boys, but even a slight elevation in girls can have a pronounced masculinizing
00:34:51.660
And so girls that have this condition where their, it happens to be their adrenal gland is
00:34:57.560
producing relatively high levels of testosterone, that condition is corrected at birth, at least
00:35:05.580
And those girls on average end up far more than girls who don't have that condition to
00:35:15.440
They want to play with whatever toys the boys are playing with.
00:35:23.700
They're more likely, even though the rates are very low, to have a male gender identity than
00:35:30.960
And the only difference there is that they had increased exposure to testosterone in
00:35:38.680
So it's clear that that sex differences in that early exposure to testosterone have a
00:35:44.720
huge amount to do with who we become because this is prior to puberty.
00:35:49.680
So if boys are engaging, you know, more physically active, basically, especially with each other in
00:35:55.800
childhood, that's going to set the stage for later behaviors, you know, almost regardless
00:36:04.000
I should say that boys who grow up to be gay are much less likely to engage in rough and
00:36:11.840
But those boys, so that's interesting and that's kind of a mystery, but those boys who
00:36:15.540
grow up to be gay have the same pattern of sexual behavior of boys who grow up to be
00:36:23.400
So being exposed to high levels of testosterone in utero seems to always shape male sexual behavior
00:36:31.060
to be masculine, to shape the desire for a higher number of sex partners, ultimately,
00:36:38.700
So prenatal testosterone sort of lays the groundwork.
00:36:41.240
Throughout childhood, T levels between males and females are pretty much the same.
00:36:45.560
And then puberty happens and there's this spike.
00:36:47.580
And I think we all know what happens during puberty, like the secondary sex characteristics show
00:36:51.280
up, you get taller, more muscle mass for men, body hair, facial hair, deeper voice.
00:36:58.800
Like how is that testosterone surge influencing the mind and behavior?
00:37:03.240
I've talked to a lot at this point, just in talking about the book, a lot of men and
00:37:08.740
trans men, which is interesting, you know, people who lived as women and then took high
00:37:12.060
levels of testosterone about what it feels like.
00:37:15.420
Most men say that they were preoccupied with sex, preoccupied with their position in the
00:37:23.560
status hierarchy and social relationships among boys and then young men.
00:37:28.520
So again, you know, I have this 12 year old and that's what he talks about a lot.
00:37:32.040
He's not the sex part, but the, who is popular, what they do, how they behave.
00:37:37.360
And this is all fascinating because it seems all of them are really, really attuned to status
00:37:43.480
hierarchies, you know, and there's a great evolutionary reason for that.
00:37:51.220
That's also extremely important, but the way they navigate competition within those hierarchies
00:37:58.340
Girls don't use this like very direct form of aggression and physical aggression.
00:38:02.560
They tend to use gossip and passive aggression and backstabbing.
00:38:06.300
I hate to say, and now social media, which I think that's a horrible way to harm people's
00:38:12.700
Boys are more likely to go up into somebody's face and call them an a-hole or something.
00:38:17.240
And so there are these, and they're more likely to get into obviously physical, aggressive,
00:38:23.560
And of course that depends on culture, you know, around the world and just within say our
00:38:28.420
United States, like there's obviously different norms around beating other guys up.
00:38:37.600
So yeah, I think that's what's going on psychologically is sex and status competition.
00:38:42.780
And I think the point to make is that there is a cultural, like, so we have this biological
00:38:46.020
thing going on, but like culture can kind of direct it, right?
00:38:49.780
So in the West, it's like, well, how do you get status?
00:38:52.940
It's like, well, you go, maybe you play football or you run for student council or it's like if
00:38:59.540
In another culture, it might be something different, but there'll be a drive for status
00:39:04.300
somehow because the idea is like, if you get status, the chicks will like you.
00:39:09.920
I mean, but you don't, you might not even think of it that way at the time.
00:39:13.240
You just seem driven to gain status over other boys, you know, or young men.
00:39:19.460
And yeah, it seems like a benefit is that the girls start to pay attention to you.
00:39:23.580
So culture, people sort of miss this point about how incredibly important culture is
00:39:30.740
and nobody should resist the facts of biology about, you know, and the role in all of these
00:39:39.560
They shouldn't resist that because they think that culture is important or culture is more
00:39:46.700
But what's interesting is how it interacts with our biology in these fascinating ways that
00:39:56.500
Well, I think you, you made some, some guy, I forgot who it was.
00:39:58.900
I think it's the guy that wrote the trouble with testosterone.
00:40:02.700
He said like, if you talk about the influence of culture and biology, kind of the interplay
00:40:06.980
they have, it's like, if you gave testosterone to a bunch of monks, they would start competing.
00:40:13.460
Like they wouldn't start beating each other up.
00:40:14.900
They would start trying to out-compete each other who can meditate the most or who can do
00:40:19.700
But if you gave like testosterone to a prison gang-
00:40:24.100
You'd probably see just a bunch of, you know, shanks and things like that.
00:40:27.520
That's what's fascinating is that it seems to promote whatever is necessary for a man or
00:40:36.260
an animal, you know, in a given environment to gain status or to, you know, avoid, just
00:40:46.720
So it sort of increases your attention to those signals of status is how it seems to
00:40:53.740
Your vigilance and your attention and your striving for status in whatever way is necessary.
00:40:59.580
And in our deep history and still in many parts of the world, that was physical aggression.
00:41:04.260
So that's why males are larger than females and still are, you know, so there's still
00:41:09.900
those cues and women are still attracted to big, you know, tall, say, muscular, assertive
00:41:17.960
men, even if there isn't any actual reproductive benefit.
00:41:24.380
So males are also still wired to, yeah, really care about status and be responsive to those
00:41:31.380
cues in a way that women, you know, are responsive to different kinds of cues.
00:41:35.380
And status just is not quite as important for female reproduction, of course, as it is
00:41:40.840
It still matters because females want to compete for the high status males and there aren't
00:41:47.540
Well, let's continue on this, this, this status strain here.
00:41:50.140
So I think it's interesting, you talk about studies that testosterone can, I mean, okay,
00:41:56.160
influences this drive for status chronically, systemically.
00:42:03.120
If, if a male experiences an increase in status or a decrease in status, there can be these
00:42:10.020
sudden drops of testosterone or increases in testosterone, testosterone.
00:42:17.220
Because I mean, the production of testosterone takes a while.
00:42:19.080
It has like the pituitary gland, it's a signal.
00:42:25.680
Like a guy can watch his favorite sports team lose and like his T levels will drop immediately.
00:42:32.960
So I don't want to overstate the prevalence of this phenomenon.
00:42:38.440
And however, it does exist in it, in humans and in non-human animals.
00:42:43.240
And I think it'll be helpful just to say what happens in non-human animals.
00:42:46.520
So the Syrian hamster has been studied heavily regarding these testosterone changes, which
00:42:55.620
And again, it's not so much how much testosterone you have as a guy in general, as long as it's
00:43:01.280
within the normal range, your sort of baseline level seems not to be super predictive of much.
00:43:07.400
What does to me seem to be important is prenatal testosterone and these changes that you're
00:43:12.180
talking about in social, that are a product of social interactions.
00:43:19.820
So in Syrian hamsters, if a Syrian hamster has a fight with another male for territory,
00:43:27.440
so territory is the equivalent of any kind of resource in humans, because you need territory
00:43:31.420
to get females because females will, will feed on the territory that a male can guard basically.
00:43:37.220
So high status males will have larger territories in the wild anyway.
00:43:41.660
And the outcome of, if you think about it from an evolutionary point of view, or even
00:43:47.200
So if you're fighting physically with another guy, if you lose, you need to know on some level
00:43:55.280
Like you can't go, if you're losing consistently against other males in physical competitions,
00:44:04.440
Basically, if somebody's in your face, you need to run away.
00:44:07.560
You shouldn't be challenging them because you want to survive to try to win some other
00:44:11.840
competition in the future so that you can mate, right?
00:44:14.300
So how do animals make those decisions about how do they know, well, I need to, you know,
00:44:25.400
So when you're, when someone's threatening you, it may trigger in you the feeling that
00:44:31.300
they're threatening you physically, even if it's just a chess game or a tennis match, definitely
00:44:36.660
in a football game, or just some guy is in your face.
00:44:40.260
There's all kinds of situations where two males are competing for status in humans in some
00:44:46.740
So in the, in the hamsters, if a male loses a physical fight and he submits, right, he ends
00:44:55.020
up by going on his back and getting on his back and submitting, his testosterone will tank.
00:45:00.800
So first of all, when they're facing off, they're, both of them have an increase in testosterone.
00:45:05.260
The loser will have a pronounced decrease in testosterone.
00:45:09.300
The winner will maintain high testosterone or it will get higher.
00:45:12.940
And if you, and then the loser will fail to defend itself or defend its territory against
00:45:20.720
a future threat because he's lost, he's that, that reduction in testosterone is somehow telling
00:45:29.800
So if you block that, that reduction in testosterone after he loses, he'll continue to defend his
00:45:39.660
And then he'll get his ass kicked and he could die, right?
00:45:42.260
So it seems like the testosterone drop is adaptive for losers.
00:45:47.280
A testosterone rise is adaptive for winners because it's a way of signaling, shaping the
00:45:55.860
So if you're a winner, you know, in the face of threat that you're a winner, you act like
00:46:03.540
If you have lost, you are fearful and anxious and you retreat from confrontation.
00:46:08.980
So we have all varieties in humans of those responses to competition, but it seems like testosterone
00:46:16.640
changes in the moment, in the face of competition are playing a role neurologically to set people
00:46:23.960
up for reaction to future competitions and may help to account for different, uh, even in
00:46:31.760
ways that people engage in competition in general and just, uh, feeling like they are fearful
00:46:39.020
or feeling like confident in the face of, uh, competition.
00:46:43.040
So yes, there's all kinds of examples in the human literature where either from sports or
00:46:50.580
again, from competitions that are not physical even.
00:46:54.460
And then there's all these competitions that we don't measure, which are just males getting
00:46:58.400
each other in each other's faces in some way, having subtle competitions where there
00:47:05.480
It's tough to pin down experimentally, like exactly when they happen and who they happen
00:47:12.600
But from the literature on non-human animals, it seems clear that we do know that when testosterone
00:47:18.720
rises in these social situations, it can increase dopamine, which is a hormone that is rewarding
00:47:27.900
and, and promotes the same behavior in the future because it, so it increases motivation
00:47:33.920
for the same behavior in the future because it felt good last time.
00:47:37.300
And cortisol is a hormone that is associated with stress and anxiety, and that can be paired
00:47:42.780
with the testosterone drop and that can possibly motivate the animal more towards a retreat
00:47:51.160
So there's like a Matthew effect going on, right?
00:47:53.420
He who has will be given more, he who doesn't have will be taken away from.
00:47:58.520
So yes, I think that's right, but it's adaptive for all basically based on, but it's a way to,
00:48:04.300
you know, if you're in a stressful situation, it's possibly a way to, um, condition males to,
00:48:12.780
about how to respond very quickly so they don't have to stop and think about it.
00:48:16.940
And I should just say, you raise a really interesting question.
00:48:20.640
How does testosterone change in these situations?
00:48:23.340
Because like you said, the signal to produce testosterone in the testes comes from the brain.
00:48:29.780
It comes from the hypothalamus and pituitary in the form of luteinizing hormone.
00:48:34.380
And it takes an hour for that hormone to get from the brain to the testicles and to result
00:48:40.360
in a, in, in a pulse of testosterone, essentially, then that testosterone have to go through the
00:48:45.480
blood and alter gene transcription, which, you know, theoretically should not have immediate
00:48:51.800
So the answer is, we don't know how social interactions can cause these testosterone rises.
00:49:00.040
It may be that it's not coming from the testes, or it may be that it's not coming from LH,
00:49:04.760
it may be that there's an increase in adrenaline and that somehow adrenaline acts on the testes
00:49:11.980
to release testosterone that's kind of hanging out there, but we don't know.
00:49:17.400
And this is something that I've been obsessed with a long time.
00:49:22.380
So testosterone makes a boy or, you know, teenage boys, young adults, young adult males,
00:49:29.820
Well, I wouldn't say makes, but yes, heavily influenced.
00:49:34.120
But, and then also we've talked about this a little bit, aggression, like it makes,
00:49:37.780
causes or influences males to be more aggressive.
00:49:43.200
I mean, what's the advantage of being aggressive?
00:49:44.700
Is that just helps you get access to mates and resources?
00:49:49.820
So there's no, there's actually not a big sex difference in aggression.
00:49:59.220
Using, so, and what's interesting is if you think about the strategies over human evolutionary
00:50:05.320
history that males and females would use to maximize their reproduction.
00:50:09.500
And, and that's what natural and sexual selection acts on is, you know, the traits that animals
00:50:16.940
possess that allow them to maximize reproduction.
00:50:19.200
So for females, taking physical risks is a bad idea because you need your physical integrity.
00:50:31.100
That's what, because you don't have to worry about fighting for mates, right?
00:50:33.940
You have to worry about having the energy and health that you need to bear and feed your
00:50:41.740
So it doesn't pay off for females to take physical risks and they don't have that need to compete
00:50:49.840
physically for mates, although they compete for mates, but in ways that don't put their
00:50:57.300
So males are relative to females over evolutionary history have benefited from physical aggression
00:51:05.460
because they, that's what their bodies are in a sense built to do relative to females.
00:51:10.700
That's where they're putting their reproductive energy budget.
00:51:13.680
That's why they have bigger bodies and more muscle.
00:51:19.300
So that muscle, that's a history of using their bodies to compete physically for mates.
00:51:24.900
So we retain that in a modern environment that, and that's a, you know, again, that's attractive
00:51:31.320
It's not the case that they have to compete physically anymore.
00:51:35.620
So in different cultures, women are going to prefer men who have high status, whether it's
00:51:43.680
Like I'm married to a philosophy professor and he's definitely never gotten into a fight,
00:51:49.720
but he's super attractive to me, partly because, you know, partly because of his status, but
00:51:55.820
it's not, you know, he got that with his brain, not with his body, but it depends on the environment
00:52:03.340
So we have this evolutionary history of physical aggression paying off, but it still plays
00:52:11.440
I mean, you can see the propensity for physical aggression in males, just like crime reports.
00:52:15.840
If you look at murders, physical assault, sexual assault, it's pretty much all dudes.
00:52:21.220
You know, there's, there's women there every now and then, but it's mostly dudes.
00:52:23.620
But then if you look at crimes like fraud, shoplifting, et cetera, there's still more men, but
00:52:29.580
you know, women, that's more of where they kind of do their crime.
00:52:35.180
So women are going to commit crimes, but they're not going to, they're just much less likely
00:52:39.360
to put themselves physically at risk to commit those crimes.
00:52:44.500
Males are much more likely to put themselves physically at risk to commit crimes and to do
00:52:50.180
Like to show off to, you know, thrill seeking men are just far more likely to do that physically.
00:52:57.440
So we've talked about testosterone's effect on behavior in males.
00:53:02.020
Something that's been getting a lot of press lately is the role of testosterone in athletic
00:53:09.760
So there's a lot of controversy and confusion around this area, but I'll just say that the
00:53:21.440
And people who try to make it seem confusing from my point of view, have a political or
00:53:31.400
It's totally clear that in the almost all sports, there are some exceptions, males, men.
00:53:40.540
So if you're looking at the elite level, if you're looking at, you know, comparing highly trained
00:53:44.520
people, you know, who are all taking care of themselves, all healthy, eating well, sleeping,
00:53:49.360
training, you know, et cetera, men blow women out of the water.
00:53:56.080
There are in many sports, even at the Olympic level, there will be thousands of men who will
00:54:09.440
In some endurance sports, there are some exceptions to that.
00:54:16.480
Like it is, again, this is abundantly clear that this is an effect, a consequence of males
00:54:25.620
Like for all the reasons that I, you know, all the things we've been talking about physically,
00:54:30.840
nevermind what might be happening psychologically, which, which is a question, but the physical
00:54:36.660
advantages are immense in terms of the, what happens that is irreversible, first of all,
00:54:44.140
So there is some aspects of pupital changes that are reversible and, but there's others
00:54:49.940
So the ones that are permanent are obviously the bone growth.
00:54:53.440
So the height, bone density, to some extent is irreversible.
00:55:00.920
And that happens because of the increased muscle during puberty that exerts forces on the
00:55:06.740
developing bones that causes them to increase mineralization and density.
00:55:14.680
So you have larger bodies and on those larger bodies have much more muscle and testosterone
00:55:22.960
causes stem cells during puberty to differentiate into muscle, preferentially over fat.
00:55:30.600
So those don't reverse so that in adulthood, if you suppress, if you're a man and a male and
00:55:38.720
you suppress your testosterone, you will not lose all of that muscle advantage you would
00:55:46.580
So there's height, there's bone density, there's larger hearts and lungs, there's increased hemoglobin.
00:55:58.020
That's a direct effect of testosterone and hemoglobin carries oxygen around the blood.
00:56:04.540
So you'll have more oxygen fueling the greater amount of muscle mass.
00:56:14.300
Males, again, the upper body strength just blows away the upper body strength of females.
00:56:26.220
I mean, I could go on and on and you have more power.
00:56:30.900
So sports that emphasize power, like weightlifting, like Laurel Hubbard, for instance, is a trans
00:56:39.220
woman who competed in weightlifting in the Olympics recently.
00:56:44.620
And there was a lot of controversy and questions about whether she, because she was a person who
00:56:51.520
was male, who transitioned to living as a woman and had stopped her testosterone and taken estrogen.
00:57:01.120
And the question was, would she have an advantage in weightlifting over natal women?
00:57:08.480
And the answer is yes, because she went through male puberty.
00:57:11.840
She's going to have a huge advantage because all of her muscle mass that she gained as a result of male
00:57:17.580
puberty doesn't disappear even when testosterone is stopped for something like even five years.
00:57:23.240
So there's enormous advantages to going through male puberty.
00:57:27.600
And those do not disappear when testosterone is suppressed in trans women.
00:57:36.540
There's just no, it's not that women, some people are saying women aren't trying hard enough.
00:57:46.040
So, I mean, when people finish this book, like, what do you hope they walk away thinking?
00:57:52.440
Of course, I'm incredibly interested in testosterone and the power of testosterone and how it shapes who
00:57:59.600
But I think one of my overarching values in life is that science and knowledge is, it's crucial for us
00:58:09.400
to have clear views about reality and to not fear the truth and to do whatever we can to find and
00:58:18.700
That's what I see my job as a science educator.
00:58:22.100
And that when you learn how things work, you have more power to make the world a better, safer, more
00:58:31.280
And so that is one thing I want people to come away with.
00:58:34.080
I want them to see that it's possible to be clear and honest and open, but also sensitive
00:58:40.720
And then the other point is, of course, about the hormone.
00:58:43.980
There's just so much evidence that this one molecule shapes our society in these really
00:58:52.040
And that the more we understand about how it works, the more we can capitalize on the positive
00:58:57.240
aspects of being a man, which we didn't even talk about.
00:59:00.380
We didn't talk about toxic masculinity, which I really don't like at all.
00:59:23.960
Nobody should be ashamed to be a man, to be masculine.
00:59:29.200
And if you look at the news and who's risking their lives to save the lives of others, it's
00:59:35.460
You know, there are really brave women who are doing that too.
00:59:38.640
But over, I don't know why I'm getting so upset.
00:59:45.180
And I think there are a lot of struggles that we need to acknowledge that men are facing.
00:59:53.140
And some of those struggles are around puberty and adolescence.
00:59:55.900
And I wish that more people felt they could talk about their struggles and have support.
01:00:01.460
And that this ultimately is the way to making the world a better place.
01:00:05.040
And there's so much positivity around masculinity.
01:00:11.360
And this whole narrative about toxic masculinity that seems to be increasing, I wish would end.
01:00:18.440
No, I think that's, I think that's, I like how we ended on that.
01:00:26.780
I don't even, I don't even know what it means anymore because it gets bandied around so much.
01:00:30.780
But then we also forget about all the great things men do.
01:00:34.400
And I think that's, I think men need to hear that as well.
01:00:36.760
Because I think you're just kind of scolded all the time in the popular culture and it can get you down.
01:00:42.080
Yeah, and I'm, you know, you're, I assume working hard and being a great dad.
01:00:47.700
I mean, to me, having that involvement in the family and having that kind of support and men bring something to the family that women just don't.
01:00:56.460
And I watch this in my own family, the way that I am with my son and the way my husband is with my son is very different.
01:01:04.600
I'm not saying that people won't, that every family has to have a male and a female or a mom and a dad.
01:01:12.300
But there is something that is so important that dads are bringing to the family.
01:01:18.180
And again, and also I have to, people aren't going to like this, but to the world, there is a different way of being in the world that I'll just say quickly.
01:01:27.020
And that I asked my students at the end of class, I usually ask them, what would the world be like without men or something like that?
01:01:35.520
And just a couple of years ago, a student said, I don't think we'd have tall buildings.
01:01:39.700
Or I think I said, what would happen if we castrated men?
01:01:41.800
Or some other student said, you know, we should castrate all men or something ridiculous.
01:01:45.240
And this other student spoke up, which was great.
01:01:49.180
He said, I don't think we'd have tall buildings.
01:01:50.940
I don't think we'd have the kind of innovations that we have.
01:01:54.060
And that's controversial, of course, but there is something to it.
01:01:57.340
That competitiveness, that drive for status sometimes can be destructive, but can also be incredible motivation for innovation.
01:02:06.860
And that's something that remains to be explored.
01:02:09.280
It's sort of too politically incorrect, probably to study it seriously, but I wish we could.
01:02:14.800
Well, Carol, this has been a great conversation.
01:02:16.200
Where can people go to learn more about the book and your work?
01:02:28.120
And my book is on Amazon and wherever you like to get your books.
01:02:33.000
And if you do get it and like it, I never ask people to do this.
01:02:37.140
Just if you could review it on Amazon, that really helps.
01:02:50.260
She's the author of the book, Tea, the Story of Testosterone.
01:02:53.340
It's available at Amazon.com and bookstores everywhere.
01:02:55.500
You can find out more information about her work at our website, carolhooven.com.
01:02:58.960
Also check out our show notes at aom.is slash tea, where you can find links to resources,
01:03:11.380
Well, that wraps up another edition of the AOM podcast.
01:03:14.080
Make sure to check out our website at artofmanless.com, where you find our podcast archives,
01:03:17.540
as well as thousands of articles written over the years about pretty much anything you think
01:03:20.700
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01:03:43.660
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01:03:45.140
Until next time, this is Brett McKay, reminding you not only listen to the AOM podcast, but