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I think that can be part of the sort of implicit negative reaction to genetics is we love control and thinking about this factor that's not fully within our control can be again, it's both liberating and horrifying in equal measure.
C
And now the good fight with Yasha Monk. To what extent is our behavior determined by genetic influences? Are many social outcomes downstream from the genes we have? Or do they depend on things like our parents wealth, the kind of household we grew up in, the kind of opportunities we had? And why are so many people resistant to looking at the scientific evidence that comes from things like twin studies, which do seem to suggest that one important component of these outcomes is driven by genetics? Why, more broadly, is much of that work, right coded? Why do people tend to assume that when you look at genetic influences on behavior, you must be favoring right wing policies to deal with questions of education or social ills like crime? Well, the best scholar who has thought about these topics and who combines an emphasis on the genetic influences on our behavior with with left wing political commitments around questions like education and crime is Katherine Page Harden. Page is professor of Psychology at the University of Texas at Austin, and she is the author of two really interesting books, the Genetic why DNA Matters for Social Equality, which came out about five years ago and was widely discussed, and a new book called Original How We Became Evil and what We Can Do Do About It. In the last part of this conversation, we really go deep into questions of how to grapple with the genetic influences on evil behavior. If there is no such thing as free will, does that undermine the extent to which we should judge our friend for treating us poorly? Or to which we should punish a murderer for the horrific crime that they have committed? As in big parts of this conversation, you'll see that Page's answers are perhaps somewhat surprising. But it turns out that we share a broadly similar outlook on this, including from some of the work that I've done, this is really an Easter egg for super fans of me in my dissertation. So if you want to listen to that part of the conversation, if you want to support the work we do here. Please become a paying subscriber of this podcast. Please go to writinglotashamunk.com Listen. Paige Harden, welcome to the podcast.
B
Thanks for having me.
C
So thinking about genetics, and particularly the genetic influence on human behavior is, for lack of a better word, often right. Coded. Right. People assume that it's people on the political right who want to emphasize the genetic determinants of human behavior. And it's often people on the left who are very allergic to this, who say that, you know, actually, genetics doesn't really explain anything. It's social forces. And somehow if we accepted that genetics influences human behavior a lot, then that would lead us down all kinds of dark alleyways. You, I believe, see yourself and think of yourself as a woman of the left, and you also think that we have, in many areas of our life, underestimated the role that genetics plays in explaining human behavior. Let's start with the latter part of this. You know, why should we think the genetics is such a big determinant of human behavior?
B
Yeah, I think we should think of the importance of genetics because we have a lot of scientific evidence that genes matter in shaping our lives. And we can see that in twin studies. That was kind of the workhorse of genetic science and the 20th century. How similar are genetic relatives, even if they haven't been raised together for certain aspects of their behavior? And we see it now with our more modern technology where we can actually look at specific segments of DNA. How do they differ between family members even, and are beginning to discover how do they help shape behavior. It's very rare that they're determining behavior, but my PhD advisor from graduate school is very famous for a paper called the Three Laws of Behavior Genetics. And the third law of behavior genetics is everything is heritable, which means that everything that differs between people, when you look at it scientifically, tends to show some influence of the genes that you were born with. So I'm a scientist. I've been working in this field since I was 18. And so it's important to me just because I think it's a scientific fact that's sort of incontrovertible at this point in time time that genes influence behavior.
C
So let's walk people through these arguments a little bit step by step, because I think a lot of people have heard about twin studies and they know that nowadays there's probably more modern techniques that are slightly different. What exactly do the twin studies show and establish?
B
Yeah. So twin studies are typically comparing identical twins who were conceived from one egg, one sperm and then there was an error in early cell duplication. And now there's two people, their similarity in some trait to the similarity of fraternal twins, who are the sort of twins who look like ordinary siblings. Two sperm, two eggs, just happen to share a pregnancy. And that logic you can expand out to compare, you know, full siblings to half siblings or adoptive parents and children to biological parents and children. What all these designs have in common is that they're taking people who share a social relationship. So both fraternal twins and identical twins have the same social relationship as siblings being raised in the same home with the same parents, but have different genetic relationships.
C
And the idea here obviously is in a way to try and hold as many things constant other than the genetics. Right. So you're going to assume that perhaps there's difference between siblings. Right. Perhaps the family became a lot richer over the course of three or four years or something like that. And so if one sibling's three years younger, you can say, oh, it's because of that. Right. Well, if you're just comparing identical twins to non identical twins, you know, there's no three years in between for the family to become richer.
B
Yes. And it's the same pregnancy. Yeah. It's the same maternal smoking, it's the same neighborhood they happen to live in. It's the same prenatal supplements that mom was taking. And so the only thing that the idea, and we can get into whether this assumption holds, the only difference between them is this difference in their genetic relationship. And then you're trying to see, does the similarity in their behavior track the similarity in their genetic relationship, or does it track the similarity in their social relationship? One of my favorite studies looks at twins where the mom is wrong about whether or not the twins are identical or fraternal. So the mom thinks that they're fraternal twins because they look different to her. She knows them so well. But when you look at their DNA, it's clear that they're identical. And do they look as similar in their behavior as identical twins typically do or as fraternal twins typically do?
C
And that's get us whether the assumptions of a mom somehow influences their behavior. And it's really all about the social environment in these super subtle ways. And what does the study find?
B
It shows that it tracks their actual genetic relationship and not what the mom thinks that they are. So it's not about being raised in the same home. It's not explainable by that. It's not explainable by the parental expectations of how similar they Would be it's really the best predictor of their similarity is how many genes do they share. I want to go back to what you said at the beginning, which is that is that result right coded or left coded? And it really depends on what you're talking about. So some of the earliest twin studies were done around schizophrenia and showing that the best predictor of having schizophrenia is having an identical twin that also has schizophrenia. And subsequent twin studies have shown that you also see this higher similarity in identical twins for addiction, for sexual orientation, for depression, for all sorts of mental health problems.
C
And that might be left coded because it implies that it's not your fault.
B
Yes, exactly. So what we look and if we see, like, are people who have more right wing political ideologies versus left wing, are they more likely to believe twin studies or more likely to believe that genetics influences behavior? It very much depends on what behavior you're talking about, where you have liberals who are much more likely to say, yes, identical twins are more similar for addiction. Yes, sexual orientation is partly shaped by the genes that you inherit. And it's the application of this to specifically cognitive ability and achievement that tends to be more right coded in the United States.
C
Tell us a little bit about the magnitude of these findings. Right. So, you know, when you compare identical twins to fraternal twins, give us some statistic or some kind of concrete measure that allows people to get a sense of how much variation is there between identical twins, because obviously there's still some variations. How much more variation is there once you get to fraternal twins? And then, you know, how does that compare to a half sibling, for example?
B
Yeah, so there was a really big meta analysis where they pooled data from 50 years of twin studies. So I think it was something like 15,000 pairs of, or 15,000 studies, like millions of pairs of twins. And the punchline was that on average, across behavior, but also medical traits, about half of the variation in outcomes was due to genetic differences between people. So one way to think about that is if people were all genetically the same, how much could you make outcomes the same? And you could shrink people's differences by a substantial degree if they were all genetically identical. It varies by trait. So for things like schizophrenia or height, these are in modern populations, almost all of the variation between people is due to their genetics, Whereas things like personality or depression, it's about half. And then when you start talking about, like, education, it's like a fifth to a third. So it depends on the phenotype that you're looking at. It Also depends on the population that you're studying. So if you're looking at a nutritionally deprived sample, you know, people who didn't get enough to eat in childhood, you're going to get less of a role for genes than if you're looking at people who all had ample access to food. And most of the differences between them are necessarily all about their genetics because there's not really that much environment.
C
The average height in China has shot up over the last 30 years. There's a really nice example of that in a writer who was in Sichuan teaching in the 1990s. I've had him on a podcast a few years ago and he's I think, a little shorter than me. He's like five, seven or something. And he was the tallest person in the classroom. And then he went back a few years ago and suddenly he was one of the shorter people in the classroom. And he was really struck by that. So obviously it's not that the genetics of people in China has completely transformed over the course of 30 years. It's that they've overcome this, this, this nutritional disadvantage that they had as recently as the 1990s. So obviously, if you're comparing, you know, if you're in a place where the family doesn't have enough money to, to, to buy enough food for all children, and one child, for one reason or another, is favored by the parents, or is better at elbowing their siblings out of way in order to get to the food, they might end up being much taller. And so it's not genetically determined, it's determined by the social factors. But once you look at a context where everybody gets enough to eat, the genetics is the thing that really drives it. The other interesting finding here is that you might think that genetics plays the biggest role early in life and that later on its influence sort of fades as people's paths diverge, as they make different choices, et cetera. If I'm understanding it right, the actual finding is the other way around. Right?
B
Yeah. So what you see is that twins get more similar over time, and people who don't share genes get more different over time. Such that you seem to. If you're estimating what scientists call heritability, those heritability estimates tend to go up with age rather than down. If you're looking at the similarity between adopted children with their parents or adopted children with their siblings, they're most similar to these non genetic relatives in childhood. And then as they leave the family home and as they have more control over their environment, the evidence of the genotype tends to emerge over time. And one way you can think about that is that especially in modern contexts, people have increasing amounts of control over their environments, both conscious and unconscious. As they go through life, they pick their peers, they pick their partners, they pick their daily routines, they pick what city they want to live in. And in each of those choices reflects in, even in small part, your own personality temperament. Then there's going to be a feedback loop where the environment is reinforcing those initial genetic differences. And that kind of sense of I'm becoming more like my identical twin. I'm becoming less like people who are genetically different from me. That increases over age rather than decreases over age.
C
It has been a long winter, but now, finally summer is here. As I'm recording this in New York, it really feels like mid July and I'm trying to figure out what to wear. When I'm just going to the gym. I usually just wear a Persuasion T shirt, which looks pretty good. But when I want to go to a social occasion and look nice but not overly formal, I always struggle to figure out what I should wear. Well, I have started wearing really nice linen pants and shirts from a company called Quince. They are perfect for the summer season. They are really nice and soft, but lightweight. And everything at Quince is priced 50 to 80% cheaper than comparable brands. A few weeks ago I got a lovely 100% European linen relaxed long sleeve shirt. It's really casual but elegant and I've been wearing it through our mini Heatwave. I strongly recommend it. If you want to look good without spending a fortune, Quince is the way to go. Elevate your summer wardrobe. Go to quince.com Good fight for free shipping on your order and 365 day returns now available in Canada too. That's Q-U I N C E.com Good fight for free shipping and 365 day returns. Quinn.com Good fight what are the main kind of responses that people give to this who are skeptical of the genetic explanation? And I guess, you know, perhaps let's start with popular objections and then go through some of the most sophisticated scientific objections. And I should say that my wonderful podcast producer Leo is shouting at me at all caps over WhatsApp because she has an identical twin and she keeps saying no way are we gonna get more similar as we get older. So, you know, I think to a lot of people a lot of the sense of self is found up in many of these questions.
B
Yeah, so there's a couple of objections. One is I Think a distaste at even just doing the research. And I think this might be part of this is piggybacking on the comment that you just made that people's identities are bound up with their behavior. And it can feel inherently reductionistic or inherently threatening to human agency to make really valued parts of people's identity, especially when your child or very problematic or darker parts of people's behavior to make them the object of scientific study. And especially scientific study at the level of a genetic analysis, it collapses across our sense of ourselves as embodied animals and our sense of ourselves as choosing agentic, you know, wills or reasons. And so, you know, one objection is just like, ick. It gives me the ick to think about genes influencing my sexual identity or my behavior that I. My religion, my religious activity. Like that can just be uncomfortable. I think another is that regardless of the results and are. Regardless of how the results are presented, there's the fear that it's necessarily kind of giving ammunition to the most reactionary or eugenic or racist elements within a society. You know, there's a history of people using genetics to justify really horrible things. And so I think that would be the other kind of major objection, which is, even if you're scientifically correct, there's no way that you can do this work responsibly in our current political climate. And then I think there's the scientific objection, part of which is very correct, which is twin studies make a ton of assumptions. You're taking a really complicated developmental process, and then you're flattening it into this bucket is genes, and this bucket is environments. And genes and environments don't work like that. They're always combining over the course of development. So what do you mean? You have a statistical model that tries to disentangle them. And I think often people's objections can kind of float between those. Like they're animated by the fear, and that really makes them, you know, really perseverate on some of the assumptions of twin studies. And then, yeah, so they. They, you know, these are. These are not mutually exclusive. They're fluid objections.
C
Yeah. It is strange that I think this is an area on which people just have very strong moral convictions. And it's not always clear to me what drives them. But there's a lot of people who I think feel a kind of sense of threat from recognizing some of his influence on genetics. I'm thinking of one very dear friend of mine who believed for and who's an avid listener to this podcast. So she'll pick up on herself being mentioned here, but who for a very long time believed strongly that reading. The most important determinant of behavior is cultural. That the way to understand that is to study sociology and anthropology and the cultural determinants of how people behave. And obviously, if you spend time in Italy and you spend time in England, those places shape people in deep ways. And that's not a genetic difference between Italians and English people. By and large. It is a difference in the culture and the norms and what personality traits that encourages. So there's a real pull to that. But she now has two children, and when I was visiting her, she looked at me and she looked at her kids and she said, you know, Yasha, I was totally wrong. You know, the difference between these kids, it's just clearly like they come to the world with their own personalities and attitudes. I mean. I mean, you know, I wonder whether there's a kind of slightly wrong assumption about what it would take to be responsible for our personalities in the background, where it sort of feels like, on the one hand, my personality is determined by these genes, and so therefore I have no responsibility for it and it's out of my hand. And on the other hand, there's some idea of totally having chosen my own personality and then I can be responsible for it, and then I'm my own person. And I just wonder whether background assumption is wrong and whether we just have to accept that if I like somebody as my friend, it's because of the traits they have, and it's perfectly appropriate to be grateful to them for their generosity or to decide that I don't want to have somebody in my life because I think they're actually kind of mean and they're not a very good person. And whether or not it's true that that behavior is in part genetically determined is kind of respective. That's kind of irrelevant, right? Like, I have a friendship, I have a social relationship with the person that is in my life. And the question of how they came to be that person is not nearly as directly relevant to my gratitude towards them, my anger at them, my evaluative relationship. But I stand with naturally with people in my life, as many people seem to assume.
B
Yeah, I mean, I think what you're getting at there, it's just. And I write about this a lot in my new book, it's just really core to the dilemma of being a person. You know, we go through our lives and we experience ourselves in relationship with other people. We feel ourselves to feel certain things. We have resentments, we have gratitudes. We have affections, we're drawn to certain things, we're repulsed by certain things. And at the same time we have this peculiar human both gift and burden of then being able to reflect on all of that and reflect on that in this really peculiar way we call scientific, which is to measure it, to put numbers on it, to try to develop theories about what predicts it in terms of culture, in terms of genetics, in terms of parental socialization, in terms of this life event, behavior. Genetics sits right at the intersection of that, of our experiences of ourselves as, you know, loving, behaving, feeling people and also as self conscious minds that then turn ourselves into our objects of scientific study. So I don't think it's really about someone having assumptions that are wrong versus right. I just think it's. Of course you're going to come into learning about the science with priors because you've been a human, you've had a sense of yourself and you've necessarily had to develop a story about why you are the way you are. And then science, you know, on the one hand it has this kind of, although this is fading, this kind of sense of authority in culture. Like, and so people experience scientists saying here is one lens on behavior. So often as this is the only lens or this is the right lens and if that conflicts with the narrative that you've developed about your life, like of course that's gonna bring up feelings. I talk about this with my undergrads all the time. I teach intro psych here at UT and which is I think a great way to like as a scholar to keep like some theory of mind about what like lay knowledge is. Cause it's. What is an 18 year old boy from Fort Worth, Texas like think about this field. And I say at the beginning, like psychology is not gonna be like your calculus class. Like your professor going into calculus can assume that you have no knowledge of calculus, no priors, like you're not. Whereas I'm going to be talking about like attachment and personality and parental relationships. And you already have thoughts and feelings about all of that because you've been a person hopefully. And I'm not trying to, yeah, I'm not trying to say that your theory is necessarily wrong. I'm trying to add a layer of information on top of that to kind of refine some of those, those priors. So yeah, I mean I think it's necessarily a topic that people have feelings about because it's. Why are you the way you are? And you can't go through life without having constructed A story about that one way or the other.
C
How should we think about. Let's go through a few kind of questions, right? So I had Emily Oster on the podcast perhaps about a year ago. You know, one way in which she reads the influence of genetics, but also the influence of some kind of basic socioeconomic facts about you that are not really under your control is to say parents hugely overestimate the impact of little decisions they make. Right? Sort of. You know, am I, you know, do I take the kid to this ballet class or not? Do I take them to this slightly marginally better school or this other school, even if this one school is much further away and so on? You know, if I allow them to have 20 minutes more screen time, is that gonna deplete their ability to pay attention forever, et cetera? And by and large, Emmy Oster would say you're overthinking it, right? As long as you make sure they have enough food to eat and they feel loved and they're safe and they don't experience some horrible form of trauma as a kid, you know, some mixture of genetics and the very basic facts about their environment is gonna determine 99% of a life outcome. And the sort of torturing yourself with all of these things on it's just a kind of mistake. Would you broadly agree with that? Do you think that's one of the upshots of this kind of research?
B
I would broadly agree with that. I would say that a lot of things that, especially middle to upper middle class white ladies, these are the moms in my cohort obsess about, are just not going to make that much of a difference in terms of measurable child outcomes. So they're not going to meaningfully change your child's IQ score or likelihood of becoming depressed or likelihood of graduating from college if they go to a Montessori preschool versus a Waldorf preschool. I think I would refine that estimate or that conclusion in two ways. And one is parenting is a relationship. And you do things in relationships not because they're gonna change the other person, but because they seem to be the best thing for how you're relating to that person in the moment. Like, it would be really strange if someone said it doesn't matter how you treat your husband because you're not gonna change his iq. It's like, well, that's not the point of, like, behaving to my husband in a certain way is to change his iq. It's to live out our values and to. And to treat him in a particular way. That I think he deserves to be treated and wants to be treated. And I think a lot of parenting is about that. It's not like, like, I switched my, my oldest kid's school this year from public school to private school. And I didn't do that because I think that's going to private school is going to like, change his cognitive ability. At 30, it was because he was unhappy at his public school and he's happier in his other school. And so I think the reduction of parenting into like, how can we optimize on these measurable variables rather than like, what relationship are you in with your kid? And like, what, what makes them happy this year, even if it doesn't have a long term effect? I think that can be kind of missing in some of the conversations.
C
But you're presenting that I think partially as a refinement or perhaps a small objection to, to us as outlook. I guess I would put it the other way around, which is that if you're obsessed with how is every little thing I do going to impact the IQ score at the age of 30 or the likelihood to become a successful trader at Goldman or whatever your dreams for your child are, you know, a world class pianist, you're not in fact focusing on the relationship in the moment. And if you sort of are freed from that anxiety and recognize, look, these choices I'm making are not gonna make or break the kid. They're not gonna determine all of those things, then it actually frees you up to think, what is my child's need? What is my own child's need? How do we create a family culture? Everybody's having fun and thriving, and you can actually focus more on this really important question.
B
Yeah, I would agree with that. Reframing. I mean, I think I talk about this a lot in my second book, that genetics can be both liberating and horrifying in equal measure. Because I do think thinking about them and how much your child's life might be shaped by this roll of the genetic dice does confront you with the limits of maternal control. Like, I do not think of my kids at these lumps of clay that I have unlimited control to mold. And that does free me a lot, like from this kind of burden of feeling responsible for everything about them. But it also means that I need to confront that they, like, bad things might happen to them, they might do bad things. And I also have a limit in my control of how much I can prevent or shape that outcome. And going back to our earlier point, I think that can be part of the sort of implicit negative reaction to genetics is we love control. And thinking about this factor that's not fully within our control can be again, it's both liberating and horrifying.
C
And in equal measure, yeah, control is a burden, but it is also reassuring. Yes, yes, I, in a very different context, I've made this point a few times about conspiracy theories. Conspiracy theories are scary because these evil people hold all the strings and they're making the world, you know, go wrong in all kinds of ways. But it's also comforting because there's a bunch of people who have a control over the world and if only we uncover them and replace them, everything is going to be great. So in a weird way, right, the idea that there is a locus of control somewhere always has this double edged nature. And that's probably true in terms of, as a parent, right. If you have control, oh my God, that's horrible. Right. Everything depends on me. But of course, a, it's also very flattering. It's a form of ego extension. Right.
B
And I think with the locus of control, with the conspiracy theory, it's also like one factor has all of the control. And there is something I think comforting about the, the kind of cognitive closure of being able to say it's this, like it's not that the world is a messy, complex place and everything is interacting in ways that we don't understand. And so our ability to steer the ship is always kind of half guesswork. It's if we can just get rid of the deep state then every, you know, or it's, everything's going to be better. And when you, when you get into things like it's all genetics or it's all culture or it's all capitalism or whatever, that can be comforting because one problem offers the possibility of one solution too versus what we're out here saying. It's nature and nurture and culture and economies in combination and where to pull on that sweater is hard. That's a lot less comforting.
C
Let's go a little bit further down on this point of education. You know, what do you think drives educational outcomes and success? And how do you think that an unwillingness to take seriously the genetic component in educational outcomes has shaped and perhaps misshaped educational policy?
B
Yeah, that's a, okay, that's a complicated question. So if we look at the United States in the last 120 years, education has gone up. More people are educated, more people can read, more people can do advanced math skills. That is not because genetics have changed. It is because we have invested in mass public education and continue to make as a cultural priority educating every successive cohort of students. So, you know, when we talk about education, education level, the most important thing about that is it's the cultural practice that requires the commitment of adults to educate the next generation. I'm always, you know, again, I have three kids and I'm always amazed when I'm teaching my kids, helping them with their math. I'm like, you're learning algebra. They're 13 years old. This took humanity tens of thousands of years to develop, and now we teach it in a year to a 13 year old. That's an amazing cultural accomplishment. Within that system, within any cohort of kids moving through an educational system, it's obvious that kids who are raised with high income, more educated parents, go further in school. Like everyone knows that. That's completely obvious. And also kids who happen to inherit a combination of genes that make going through school easier for them, also get further in school. And those associations, if we're just looking at correlations, like correlation between a genetic indicator or correlation with ses, are about of comparable magnitude. This is not surprising to the average American. Like if you ask the average American to estimate how important is genetics for education, their estimate is about what the meta analytic twin study estimate is like people have been in a classroom, they've been around kids, they have noticed their own kids. Like, it is not saying anything revolutionary in one way to say some kids have an easier time paying attention and remembering things and manipulating information in their head and learning new vocabulary words. Our education system is cumulative and it's stratified such that those initial advantages compound over the course of education. And so if you're looking at who's most likely to graduate from college, who's most likely to take calculus in high school, who's most likely to be in the advanced math class in seventh grade, it's also not just the richest kids, but it's the kids who have a certain combination of genetic variants. I say it's not radical, but it is radical from the perspective of research on education because almost none of it considers genetic differences between people.
C
How would it change the kind of consensus in that field among researchers who don't look at genetics? I mean, off the bat, I can come up with a couple of hypotheses, right? Like one of them is that it may imply that the system is somewhat less unjust than it appears. Presumably there's some genetic correlation between a parent's academic achievement and a child's academic achievement. If There's a genetic component, there's not going to be a perfect correlation. There's going to be some correlation. Right. And so if you're only looking at, you know, to what extent does socioeconomic background or educational background shape outcomes, you say, oh, look, you know, the kids of people with college degrees go to college a lot more. This is because if you don't have parents who go to college, you just never have a chance. You don't know how to apply to college, you don't go to the right high school, you aren't read books when you're six years old and you just never have a chance. Right. Presumably if you come in and you show, well, actually, you know, presumably socioeconomic status and occasional achievement does play some causal role. But once you also put in some kind of genetic factor into the analysis, it shows out, it turns out that, you know, some percentage of that difference is predicted by the genes, then that implies, no, actually a six year old that doesn't come from a household with those socioeconomic achievements or that educational status does have a much better chance of making the way than we expected. And so all of the kind of interventions that you might have thought about, which are all about making up for the socioeconomic disadvantage is not going to make as much of a difference as we thought.
B
Yeah, okay, so a couple of things there. So one is just empirically it's kind of worked out the opposite, which is that the research that has controlled for genetics, I think has given us some of the strongest evidence of the continuing socioeconomic disparities in education. I was just reading a new preprint yesterday where they were looking at children at the very top of the distribution of. We can go into how this is made, but like a polygenic score, which is this genetic marker for. Do you have genetic variants statistically associated with going further in school? They were looking at the top end of the distribution of this genetic variable from kids from lower income families and higher income families and showing that even at the top of this genetic distribution there were still big differences that accrued over the course of education in educational outcomes by family income. I mentioned that study because I think it's a really common fear that if we start to take genetics into account, it's going to disappear. Our evidence for disparities that need to be addressed with social policy. But in actuality, the studies that have taken into account genetics have made, I think, a really strong case for the fact that there's still family economic disparities in educational opportunity in the United States. So Empirically, that's not what we're seeing.
C
And so to be clear, empirically, what you're saying is that the impact of socioeconomic status and so on doesn't disappear.
B
It doesn't disappear, but it does become
C
smaller when you take into account the genetics. Or does it?
B
I don't want to misrepresent the study off the top of my head, so I don't know how that coefficient changes. But I think without it, you're always kind of open to that, oh, well, this looks like ses, but this is really just differences in kids ability. And this study took that seriously and said, no, we're well.
C
But the other thing that really sort of frustrates me in this discussion is like, what we actually want to do is to give people opportunity. And if like we think that the causal. Right. So like, I think there's this kind of ideological point of view where it's like, well, I care about the outcome, which is that I want everybody to have good opportunity, which I agree with. Right. And then you're like, well, I'm going to deny the scientific evidence or I'm going to be really, you know, feel icky about even engaging with the academic evidence because that'll undermine the mechanism to which I'm committed because I want the right outcome. But the point of this information is that it might show that the mechanism isn't in fact going to work. That if what is driving this were not to be socioeconomic status at all, then all of these interventions that are meant to compensate for socioeconomic status are not going to give you more opportunity. Now, as you're pointing out, I always find it unrealistic that socioeconomic status doesn't play some independent causal role. And the study seems to indicate that that is the case. Right. And that's not surprising that there is this kind of weird thing where people rarefy their kind of causal model because they care about the outcome, but they forget that in doing so they actually obstruct their ability to influence the outcome in the way they hope.
B
Yes. So one thing that I sometimes say when I'm talking to education researchers is I say, I want you to imagine that every data set you have, someone has snuck in and deleted all the information that you have about student socioeconomic status. So you don't know which kids come from the poor families and you don't know which kids come from the rich families, and you still are tasked with figuring out which schools are doing what the best to improve student learning. How much harder would your job be and of course, your job would be harder because the classic problem in education is how do you disentangle selection, what's being driven by the student from what schools and teachers are actually doing. And one way you have to get at that problem is not trying to compare this kid from a rich family to this kid in a poor family without taking that difference into account. And that is the current situation that most education and research is under with regards to genetics. If you're not collecting that information, if you're not considering it, you're still trying to disentangle which schools are working, what curriculum are working, what teacher practices are working, what policies make a difference. You still have to grapple with the, like, what schools are doing versus what students are, you know, what students are selected into those schools problem. And you have a whole piece of information that's just not in there. Right. And it would be unimaginable to do it with family income, but yet we consider it like a matter of course to do it without genetics. And that seems to me like, I mean, going back to your point, which is like, do you want to know how the world works or not? Like, do we think that. Do we think that information about what causes what in the actual world we have is helpful for designing policy, or do you not? And if you do, then, like, why would you leave data on the table that could help you understand student developmental outcomes? Like, that doesn't. That doesn't make sense if you're really invested in these ends that you claim to care about.
C
Yeah, and there's areas where I've seen that happen that have nothing to do with genetics. I mean, another example is the female wage gap, which often is presented as women earn less money for doing the exact same roles. And that is not what the evidence shows. They might earn 2% less or something like that for doing the actual same roles at the same level of seniority. But the female wage gap is much larger than that in most countries, actually larger in continental Europe than in the United States, I believe. And the reason for that has to do with other things. If you become a lawyer, and the key period where it's decided whether you become a partner that makes enormous amounts of money or not is in your 30s, or, of course, in academic, where it's decided where you make tenure or not, often in your 30s. Well, if you have kids during those years, that reduces your likelihood of making partner, of getting tenure, and it puts you on a completely different earnings trajectory. And so the reason why female lawyers make less money is not that Female partners at the fanciest law firm makes less money than male partners at the fanciest law firms is that fewer capable women end up as partners in the most fancy law firms because of those kind of circumstances. Now that doesn't make it just, it doesn't make it fair, but it does mean that, you know, if you are trying to get at this problem with anti discrimination laws or with, you know, trainings for how to negotiate better, all kinds of things with sort of like girl boss, cultural messaging, you're not going to get to the problem. Right. The problem actually requires a more fundamental intervention where perhaps in academia there shouldn't be an up or out period on the tenure track. And it's make or break. And if you make it, then there's very little advancement further down the line. And if you don't make it, then you really can't ever break into. Perhaps it actually takes a more radical intervention. But you're only going to be able to understand the nature of the intervention once you understand the nature of the mechanism. And yet some people then find it somehow politically, I don't know, it's not politically incorrect exactly, but kind of counterproductive. And let's not talk about it to complicate the picture because it's somehow going to make people less gung ho about the problem. But in the process of that, you're obscuring the problem in such a way that the measures we are then taking to redress the problem can't work.
B
Yeah, I would say that this dynamic that you're picking up on, which is a mechanism or a causal story or a proposed policy is offered as a solution to address something that people really see as unjust, can then become kind of a stand in for care about the problem or the perceived injustice in and of itself. And then when you say oh, actually the causal model is different, or the mediating pathway is different, or that policy didn't work, it can be perceived as I don't think there's a problem to be solved, or I don't think there's an injustice just here, you don't care. And how to avoid that, how to avoid our means being conflated with our ends, I think is a really, it's like a difficult science communication problem. And it's something that, where people just end up talking past each other. My friend Jennifer Doliak has done this work on Ban the Box, which is like banning asking whether or not you have an incarceration history on employment applications, which was a very popular measure. It Turns out that it tends to increase job discrimination against the formerly incarcerated and also against black men generally. Because people, in the absence of information, just rely on stereotypes.
C
Because if you have a racist stereotype as an employer thinking black people are likely to have been to jail and you are able to know whether or not they have a criminal record and say, well, this applicant doesn't have a criminal record, so I'm safe hiring them. Right. If you know that there's no way of getting that information. I'm not obviously approving of that behavior, but it's what you would expect. If you think about incentives and background beliefs in the culture and so on, then you're much more likely to say, well, who knows whether this guy is actually a criminal? You know, I better hire the Latino immigrant or whatever.
B
Yeah, but it's been interesting to watch the pushback she's gotten because she's been accused of not caring about second chances for people with an incarceration history. And she's like, no, I do. That's why I actually want to know what works to get them employed, not what we think works to get them employed. And I feel similarly about education. Like if we think, you know, a certain math curriculum is going to help people get to algebra 2 and we care about that as a society, and then you look and you see actually this school is only performing better than this school because it has a higher concentration of kids who've inherited genes that make them slightly better at manipulating non verbal information. Like I want to know that. And I think part of that is being attuned to opportunity costs. Like realizing that any. Anything we do that doesn't work and anything that makes it slower to identify what doesn't work, it's not free. That's time and opportunity that we, you know, we could be using more effectively in some way. So there's just like, I think kind of like a real pragmatic case to be made for incorporating genetics. And I'm like, not because I think it's a silver bullet, but just because it's like it's another variable. You wouldn't leave a variable of comparable statistical power if it weren't genetics on the table, so why not use this one too?
C
Yeah, that's very convincing to me. We've covered a lot of the things that you talked about or some of the things we've talked about in your last book, but so far I think we've mostly covered the train of the last book in your new book in case your old book was not controversial enough. You go for the maximally difficult part of this discussion, which is, how do we then think about the problem of evil? How do we then think about the problem of people who do really bad things and the genetic determinants of that, and how should that influence our social response to it? So perhaps again, let's start with the empirical evidence. You know, is there empirical evidence to suggest that your propensity to engage in serious crime, for example, has powerful genetic determinants?
B
Yeah. So again, I would say genetic influence versus genetic determinants. But going back to the first law of behavioral genetics, everything is heritable.
C
Well, what are the other two laws of behavioral genetics?
B
Oh, you know, I should remember those. One is that the, you know, what we were talking about earlier, so that siblings raised in the same family are. Are not usually all that similar that being raised in the same family doesn't make you alike. So most of our environmental influences are much more idiosyncratic and not sort of structured by the family. I think that's the second law. And then I don't remember the first one. I'm a bad behavior geneticist. Eric, Eric, forgive me, if you're listening
C
to this, is it just that there's actually. It's sort of the counterpoint that there's some variation in the behavior of people that is not influenced by genetics. So genetics is not 100%.
B
Yeah, it's, you know, so what we see is that there are a very few extremely rare genetic disorders. You know, this is less than 0.1% of the population. They're usually just running in a few families where you see what we would call monogenic, so single gene disorders that cause people with them to be seriously antisocial, aggressive, impulsive. I talk in the book about one study of a Dutch family where the men in the family inherited this X linked gene that affects an enzyme in the brain. And they were all seriously antisocial. So they had committed arson, they had committed homicide, they had committed rape. They were multiple of them in prison. So we see evidence from the monogenic side that rare genetic variants can really warp your ability to restrain aggressive, impulsive impulses. Most people who are aggressive do not have a monogenic disorder. But we are increasingly identifying genes that are. And again, these are not deterministic. They're in combination with the environment, but that do increase your risk of becoming addicted to alcohol or drugs, of struggling with serious impulsivity problems from the time that you're a child of behaving in more aggressive ways. And I think these kind of Middle ground where it's like, there's not a single gene. There's a lot of genes that raise your probability. The correlations are about as strong as the correlations we see with, like, a childhood maltreatment history really raise these questions. And my book is me grappling with that question for the space of a book of, like, how do we make sense of that? Like, how do we make sense of the fact that we. We didn't choose to have this body and brain, and yet when we're adults and we hurt each other, we're going to hold each other responsible for our behavior. And then the other kind of theme in the book is, I was raised as an evangelical Christian when I was a young woman, and I'm really interested in how the kind of older narratives from Christianity around the inheritance of evil or the inheritance of sin continue to shape our debates about the science. You know, genetics is a little baby science, and I think we are interpreting a lot of our science through the lens of these much older, more Christian stories.
C
Yeah. And certainly in this case, you can see, again why there might be so much resistance to thinking about genetics as the determinant of this. I had a great episode of a podcast with Abigail Marsh on psychopaths. And, you know, the fact that often you can diagnose a psychopath very early on. You know, at seven, eight years old, you're relatively reliably able to tell that a child has psychopathic traits that for obvious reasons, scares parents. And particularly if you have a child that exhibits those behaviors, there's a reason why you might not want to accept the fact that, you know, your parent, your child just has this very, very strong tendency towards that. Now, Abigail March argues that actually, with the right interventions, you can at least moderate the adverse impact that is likely to have on the life of a child and on the life of the people around it. But it is very, very scary to think that this is the case. Now, here's, I think, a sort of important distinction that we need to make and that perhaps we should have talked about earlier in the conversation. I think one thing that people sometimes mix up is that genes can be hugely determinative or influential on our behavior and the fact that there's going to be family variation. Right. So obviously, siblings only share 50% of their genetics, for example, parents, especially when it comes to particular constellations of genes or recessive genes, et cetera. It's very possible that some members of a family have certain traits, but other members of a family don't. And I guess I wonder if that's part of what makes people so instinctively skeptical about this. Whereas whether likely to say, well, look, you're telling me it's all genetics, but I'm different from my parents, so it can't be genetics.
B
Yeah, yeah. We tend to think of genetics and heredity. Again, this is, it's a new idea, it's a new science. And we're grafting it onto much older ideas of heredity and inheritance. And that was like, if you had a hereditary title, you pass that down to your oldest child intact, you know, in full. If you had an inheritance and you got your parents inheritance, you got all their money. Right. Like it's being passed down. You don't get all your parents genes. You get a random 50% draw of your mom's and your dad's. One way I like to think about it is like, let's say your mom has a pantry of ingredients and she's used that to make a recipe. And your dad has a pantry of ingredients and he's used that to make a recipe. You go get 50% of the ingredients from each pantry. What recipe can you now make? It might be very different from either one.
C
If you like, you get to make surf and turf. And if you're unlikely, there's no protein for dinner.
B
Yeah, you know, you have no, like, and, and that's also why parents are always surprised by how different their second kid is. Because they're like, oh, look, this is what, this is what happens when you combine my genes with my partner's and like, what a good parent I am. And then they have their second child and then they're like, what happened? Like, this is a different person, it's a different combination. So I think getting out of the habit of thinking of genes as a source of continuity and thinking of them also as a source of discontinuity and shuffling and change from parent to child is I think, a really important kind of change in thinking to really appreciate genetics. Because you are not your parents. And part of the reason you're not your parents is because your behavior is shaped by your genes, but your genes are different than your parents. Right. You're not your parents. Clones. Thank goodness. So there is that kind of recombination. And after my first book came out and I write about this a little bit in the new one, I had so many people reach out to me who had some sort of. I was, I'm the oldest of 11 and I'm so different than my siblings. I'm the only one who went to college or I was adopted and I didn't find out until as a young person, you know, young adult. And it made so much more sense because I always felt like an outlier or my brother is really, you know, is an addict. He's never been able to stay clean. He's aggressive. And it's always made me worried to have kids because what if I carry that too? So I, you know, I think people have this intuitive sense that, like, there's family history matters, but it can also surprise you. And I think it I appreciate being able to describe, like, how that's actually happening, you know, scientifically in the body, in this kind of reshuffling whenever we create a child.
C
Thanks so much for listening to this episode of a Good Fight. In the rest of this comment conversation, Paige and I talk about what the genetic influence on evil behavior means for how we should deal with evil in our lives. Does it mean that we should abolish prisons? Does it mean that we should, you know, become more punitive? Or does it mean that we need to moderate, as Paige suggests, our animalistic instincts for retribution in the way that we might moderate our instincts for eating sugar? We also discuss the importance of keeping in mind the broader purpose of a social institution, that perhaps the right forms of punishment don't depend on the truth or untruth of free will or the particular experiences that some criminal has made, but on the broader function of punishment, the ability to keep a community safe, to facilitate all kinds of social activities without imposing needless suffering. To listen to that part of the conversation to support the work we do here to get full access to 2 ad free episodes of the God every week, Please go to writing. Amonk.com Listen again, that's writing with yashamonk.com Listen.
The Good Fight with Yascha Mounk
Date: May 30, 2026
Guest: Kathryn Paige Harden, Professor of Psychology, University of Texas at Austin
This episode features a nuanced and in-depth conversation between Yascha Mounk and Kathryn Paige Harden on the role of genetics in shaping human behavior. Harden, the author of The Genetic Why: DNA Matters for Social Equality and the recent Original: How We Became Evil and What We Can Do About It, discusses why genetics is often misunderstood, the impact of genetic research on education and social policy, and the profound personal and societal dilemmas raised by the science of behavioral genetics. Together, they tackle the “nature vs. nurture” debate, how genetic evidence is received across the political spectrum, and what it means for our understanding of opportunity, responsibility, and social justice.
Harden explains the central importance of genetics, citing both traditional twin studies and modern genomic methods:
Twin Studies:
Political Coding of Genetics:
A meta-analysis concludes that, on average, about half of the variation in behavioral and medical outcomes is attributable to genetics, though this varies by trait and population.
Environment, Heritability, and Change Over Time:
Affective/Moral Objections:
Political/Ethical Concerns:
Scientific Objections:
Harden and Mounk discuss how personal identity and responsibility coexist with genetic and environmental determinism.
Harden stresses that everyone forms self-narratives based on their experiences, and new scientific layers should refine—not replace—those narratives. (22:45–26:06, Harden)
Harden: The most important driver of rising education levels over history is investment in mass education, but within a given cohort, both socioeconomic status and genetics predict educational attainment.
Educational research tends to ignore genetics, leading to incomplete or misleading causal models and policy interventions.
Implications for Opportunity:
Mounk critiques the tendency for ideological stances to shape causal interpretations, sometimes at the expense of actually solving societal problems. (40:46–44:14)
In her new book, Harden tackles the genetics of violent or antisocial behavior, referencing rare monogenic disorders (e.g., the Dutch X-linked family) as well as broader, more probabilistic genetic risk factors for aggression or addiction.
Harden discusses her own background and interest in how ancient religious concepts (e.g., inheritance of sin) shape contemporary thinking about genetics and morality.
The conversation also addresses the discomfort with the genetic roots of psychopathy or violence, and how genetic difference functions as both continuity and discontinuity within families.
This episode offers a thoughtful, balanced look at how genetics shapes our lives and the tension between acknowledging scientific realities and pursuing social justice. Both guests encourage a stance of pragmatic inquiry: understanding the interplay of genes and environment is crucial—both for making sense of our own stories and for crafting effective, just policies. The conversation challenges easy dichotomies between “nature” and “nurture” and highlights the complex, ever-interacting factors that make us who we are.
Listeners interested in the deeper philosophical implications—such as the genetic influences on “evil” and the societal response—are encouraged to check out the full conversation via The Good Fight’s subscriber feed.