Eric Turkheimer || Intelligence, Genes, Race, and Poverty

have doctor Eric Turkheimer on the podcast. Doctor Turkhimer is the Hugh Scott Hamilton Professor of Psychology at the University of Virginia. His lab studies how interactions between genes and environments shape the development of human behavior. Today, we'll be focusing mostly on Turkimer's research on intelligence, genetics, and family background. The topic of intelligence is a favorite here the Psychology Podcast. Some of our previous guests discussing this topic include Christopher

Shaburri and Stuart Ritchie. I personally have studied this topic since the beginning of my career, so I'm always eager to engage in respectful, mature discussion on the topic. If you'd like to join in the discussion, please go to the Psychology podcast dot com and leave comments on the post for this episode. Eric. Great to have you on the show today. Nice see us, Scott. Let's jump right into this. What is intelligence? How do you define it?

What's your personal conceptualization? I think intelligence is the ability to process information and solve problems. I mean, that's pretty basic, I guess. I mean there's more technical definition of intelligence, of course, but I don't know. I guess I think that's a pretty good starting place, Okay. And then there's so there's two issues of the question of a definition, and there's the issue of measurement. Now what do you think are some of the best measures of what you

just defined that are out there right now? Well, I don't know. I don't know what you mean specifically. But there's of course an entire universe of intelligence tests IQ tests so called, of various different kinds, and those range from formal IQ tests that you might take with a professional psychologist too. In my opinion, things like the SATs that you take in high school are more or less a kind of intelligence test. They're formulated and conceptualized a

little bit differently. So it sounds like you're saying IQ test that's the answer, it sounds like you're saying because one could say that it's you know that IQ is a very limited measure of intelligence, and there's been arguments in that effect and et cetera. So I just want to make sure that we're on the same page, that everyone understands exactly what you're saying at every step of

this way. Yeah, and I think if this is where you're headed, that some of the more general things that people sometimes talk about as intelligence, social intelligence, and in our personal intelligence and emotional intelligence, those are all really important things in the world. But I guess I do think of those as separate from what I think of as intelligence per se, which is more about problem solving specifically than it is about the kind of much broader

activities that people have to conduct in the world. Yeah. Sure, but you know, so one could make the argument that certain kinds of problem solving are very contextual, based on the mean specific areas of human adaptation throughout the course of human evolution. So it sounds like when you say problem solving, you talk about a general problem solving ability that's captured by what we can talk about the G factor.

We can talk about the chief factor if you want yeah, we should talk about the G factor because I have fairly particular ideas about the G factor that may aren't necessarily the same as other people you might talk to

about it. Great, I'd love to hear what your thoughts are on the G factor, and you can understand why I want to make sure we qualify how you think about intelligence and how you think we should measure it, because you know there is no objective, you know ten commandments that God gave us saying this is the measure of intelligence, and this is how we should defind So you know, that's why it's very important for people to quarify their terms. So tell me what the G factor is? Well,

I mean, what the G factor definitely is? I mean, and I think the question is whether it's more than this, But what it I think it indisputably is. Is a statistical construct that describes the fact that ability tests, very broadly, ability tests are positively correlated with each other, and people who do well on one ability tests tend to do

well on other ability tests. People often speak as though the positive of correlations among ability tests mean that there is only one kind of intelligence that explains all of why tests go together and I don't think that's the case, even though it's the case that the correlations among different

ability tests are positive. But in any event, as a statistical matter, anytime you have a number of tests that are positively correlated with each other, it's possible in a statistical way to extract from that matrix of tests something that's called the first principal component, which describes the way that those tests correlate together. And that literally is what general intelligence or G is. It's the first principal component

of a matrix of positively correlated intelligence tests. Now, at that point, I think there comes a theoretical fork in

the road in the history of thinking about intelligence. That one school of thought about intelligence, and I think probably it's safe to say the dominant school of thought about intelligence that goes back to Charles Spearman, says that this G, this statistical G thing that describes the positive correlation among a whole bunch of ability tests, must represent some kind of actual thing inside human beings that causes those tests to go together, something in our brain that represents G,

something in our genes that represent G. I don't agree with that conclusion. I think it's much better to think of G as a descriptive thing rather than a causal thing. G is a way of describing the way mental tests go together. It's not a way of explaining why mental

tests go together. Beautiful. That is in line with a lot of recent research on statistical modeling of G showing that it's a better model to look at G as reflective variable, you know, in a structural equation model, as sort of the emergent property of multiple indicators of cognobility

as opposed to the causal force. So even from like a from a statistical model and then from a brain model theory kind of oh, you know, I'm referring to recent statistical models of G that have tried to model it as either a causal force or an outcome, you know, and research shows that it does make more sense to think of it, you said, descriptive, and that's exactly what the research suggests, is a better way of things as an emergence. You know, it's not a thing, it's an

emergent property. And also it's that seems in line with the recent research on G not making any sense as existing in an individual brain. It has to do with individual differences, you know. Even Arthur Jensen, who a lot of people malign or you know, who's done a lot of good scientific work on this topic. And we can get to some of his more controversial stuff later, but

he has done some significant scientific work. You know. He made the case that G intelligence has no meaning if you're the only one in a desert island, if you can't compare your G leveled anyone else in that island, it makes no sense to you can't measure your G. So all that I just want to say is consistent

with what you just said. Yeah, and I think to get back, I think I've placed a marker on something while we're getting to where we are about the uni dimensionality of G and intelligence, because I think that's very important that, you know, going back to Charles Spearman, who

came up with this idea in the first place. People have asked, once again a statistical question about whether all of the various covariation along the many the infinite number of mental tests that you could give to people can be fit by a single common factor. And the answer to that question, going back to Spearman, is no. In fact, as domains of tests go, it's true that intelligence is fairly well fairly well described by a single factor, more

than say personality or something thing. But Spearman himself showed that G per se, one single factor was not enough. And I think, people, well, it's two things. People. It can be very easy to think that because all tests are positively correlated with each other, that means that there must only be one thing that's causing them, and that,

as a statistical matter, is not the case. And second, once you come up with this statistical thing called G and describe it mathematically and name it as G, it's very easy to fall in love with it a little bit and think that, well, now that we have this thing called G, and it does describe quite a bit of the variation and intelligence, that it must be the single, one and only thing and the whole domain of describing something as complicated as intelligence with latent factors like G,

it's way more complicated as soon as you have more than one factor to work with. Great points, And I really like the Johnson and Bichard model that has really done some systematic analyses of the fundamental group factors of G and shown in verbal, nonverbal, and spatial are some pretty essential group factors. Yeah, so you one can reduce all these different cognitive ability tests to a single dimension, and one can do that and that does have predictive value.

Something my mentor Nickel I did my master's agree with Nicholas McIntosh at Cambridge, who I think wrote the best textbook on this topic. And you know, he constantly has made that point that you know, G, this positive manifold doesn't stop with cognitobility. There are a whole nexus of socioeconomic status. I mean, this normalogical network of G is

very broad. And one thing that is difficult to do is disentangle, you know, all of these causal forces and disentangle which is causing what you know within this normalogical network, because that it's no easy feed, is it. No? That's right, yeah. And one school of thought that I'm sure we'll get into is to sort of take G and put it at the center of that universe and say that everything else that happened is caused by this G thing, rather

than seeing G as part of a much broader descriptive network. Good. And you know, one analogy that I've been kicking around some is with the idea of health. Let's say you took a whole bunch of medical measurements from people. You got their blood pressure and their BMI and their lung capacity and how fast they could run, and all those various things, and got correlations among all those things. They

would be I would imagine positively correlated. Maybe not quite as positively correlated as mental tests are, but you'd still be able to take a first principal component out of them that describe the way all these various health measures go together, and you can call it health. And some people at any given moment are healthier than other people.

We're very accustomed to talking about it this way, and on surveys you ask people a single question, you know, how good would you how would you describe your health on a scale from one to ten. But it wouldn't occur to us to think of health as this special inner quality that people carry around, And it wouldn't occur to us to start looking for the health center in people's brain body, or start to ask, well, what are the specific genes that cause people to be healthier than

each other. We recognize health as just what you say. It's a health is a way of describing a certain domain of covariation in a very complicated network of things. But it's not a cause of those things, it's a

description of those things. I love that. And then it also taking that analogy, it seems like it would be incredibly uncompassionate and immoral to apply that same argument to say, you know, the cognitive lead argument, but we make the health elite argument and say, you know, if you take the same logic and say people who are west ces are doomed to be low sees because they have little health, well, so therefore we should give all interventions to help people

be healthy. I mean that would it's not just politically, you know, put a correct thing to say. It's called like just being a fundamentally having humanity, and it misses that health is at least as much an effect as it is a cause. Absolutely, Okay, I'd really like to

transition here to the question of is IQ heritable? And when you're answering this question, you know, when you define what heritability means, if you could please add some caveats and nuance that often gets missed in that answer to the effect, where you let people know that heritability has nothing to do with the modifiability. Okay, well, yes, I mean the simple answer the question is that IQ is terrible, and I mean as good a description of my career

as any is. It's been about understanding the complications of saying that's some kind of individual difference, like intelligence is heritable. I mean, that's what I do. And first, my preferred way of saying what it means for something to be heritable right now is this that there is a correlation between how genetically similar any two people are and how

similar their intelligence is. Right, so you can think of them in the classic way to think about that is in terms of identical and fraternal twins, and pairs of identical twins are more similar than pairs of praternal twins, and the IQs of identical twins are more similar than

the IQ's of paternal twins. You can do with other kinds of or what you can do with siblings and half siblings the same thing, and nowadays you can do it with pairs of people who aren't related, just in terms, because we can now calculate how much DNA any particular pair of people share, and you get technically different but more or less similar answers when you do it that way,

And so that's what it is. It's a correlation between genetic similarity and similarity in whatever it is that you're interested in, And as such, it doesn't show that there are genes for anything in particular, it doesn't really tell you anything about why it's the case that more genetically similar people are more similar for whatever. I'm trying to avoid using the word phenotype here, which is just a technical word for the observable ways that people are similar.

That's one thing. The other thing that you have to think about, even while I'll get the malleability in a second, The other thing that you have to think about when you think about the heritability of intelligence is what en That's not something interesting and special about intelligence that Wow, how do you like that? It turns out that intelligence is heritable. Everything about human beings is heritable. Any difference

among human beings that you can measure is heritable. So your personality is heritable, your risk of having a mental disease is heritable. And then you can get past things like that, how much television you watch is heritable, how liberal and conservative you are is heritable. Everything about people is heritable. And all that means is that in general, people who are more genetically similar are more similar. Whatever that as we go through the course of our lives

becoming whatever it is that we've become. I think of it as our genes have their finger on the scales, and they are always nudging us in one direction or another, so that wherever we come out, well, our genes had a little bit to do with how we got there, so it's not a specific characteristic of any one thing.

One more before I get the malleability. The next thing is that now, in the last fifteen or twenty years, that we can study these things not just with identical and fraternal twins or parents and children and stuff like that, but with actual measured DNA biological DNA that we get out of our bodies. We have made the amazing discovery that for something like intelligence that's heritable. There are a lot to be said about this, but in a simple sense,

there are no genes for any of these things. There is no gene that, in a known biological way, causes people to be smarter. There are genes that, in a known biological way cause people to be less intelligent because it gives them major diseases. But leaving that aside, there are no big genes for intelligence. You could say there's a lot of little genes. But I think even that

is too strong. So anyway, the genetics of intelligence exists in this matrix of everything being intelligent, and that our genes, like your grandmother said that, you know, the apple doesn't fall far from the tree. That our genes in very general ways influence everything we become. Because it's so general, doesn't have a lot of implications ultimately for the way we think about ourselves. I think most of us always knew that our genes placed a certain amount of constraint

on what was likely to happen to us. And it seems surprising the first time you hear it. Once you stop and think about I don't really think it's so surprising at all. So anyway, malleability, I think when you the first time you think about something being heritable, and the first time you think about your genes having some kind of input into an outcome, it's natural to think of it as well, this is an aspect of us

that's more fixed than we had thought that it might be. Otherwise, Well, gee, you know, I thought that my intelligence was just the result of my hard work, or how my parents raised me, or how good my school is. Well it turns out it's in my genes. There's not that much we can do about it. And that is formally, mathematically, bio logically not the case. The two things. They don't really have a whole lot to do with each other. There are a whole lot of very standard examples that I didn't

think up about it. One good one is height. Height is an obviously heritable thing, and nobody is surprised to hear that height is heritable, and we don't, in fact even think of ourselves as being able to do anything to control our height. But the fact is the height of various populations of people has changed enormously in a very short period of time. Japanese people now are about five inches taller than they were before World War Two.

That's not a genetic change. Height was very heritable before World War Two, very heritable after World War Two, and height has increased an enormous amount in Japan over that time. You can tell the same story in an interesting way with Dutch people. Before World War two, Americans were on average several inches taller than the Dutch. They are now

several inches taller than us. It was heritable then, it's herritble now there's been a big change One more example, a slightly different one that gets added from a slightly different angle, is a disease called phenol keatonuia. Phenel keatonuria is a metabolic disease that, unlike everything else we've been talking about, is controlled by a single dominant gene. It's not like all these complex things like intelligence and height.

There is a gene for phenol keatonurea. If you have the dominant gene, you're unable to metabolize a naturally existing chemical called phenolalanine that exists in food, and if you eat foods with phenylalanine, it poisons you and causes severe metal retardation and eventually death. So that's a very bits of genetic disorder in a straightforward way. However, it turns out that if you avoid foods with phenylalanine, everything's fine. So it's a genetically call disorder, and the treatment for

it is entirely environmental. Good. You said a lot of really interesting things that I hope clarify, So I want to further quarify something. So this July behavior geneticis will nounce over six hundred smps statistically associated with educational attainment,

which we know is correlated with IQ. Even if let's do the Thur experiment, Even if it comes back and says one hundred percent of individual differences in educational attainment is explained by the combination of six hundred small smps, that still wouldn't mean that the environment couldn't influence an outcome. Is that correct? Yep? Absolutely so. I think a lot of people aren't aware of that, And not only not aware of that, but a lot of my listeners are like,

what the hex and SMP. You could explain that a little bit. Well, it's literally something called single nucleotide polymorphism. I usually just refer to it as a snip. I think that's usually the way people say. A snip is a single unit of DNA A you know, the in the ACGT sequence that makes up chromosomes and genes are long collections long strings of ACGT. There are certain particular locations that only take one of two values acgt. Those

are referred to as snips. And I'm not, frankly very good at the biological technical side, so I hope I don't get any of this wrong. But we are now able to put I think two million tests for those snips on a single chip a snip chip and determine which of the two a particular individual has. And there have been very, very very elaborate detailed maps that allow us to go from which particular values of snips you have at different locations on your chromosome and how that

maps on to what genes you're carrying. So the sort of current state of the art in gene hunting is to do the hunting at the level of snips, and simply it's a very simple process of looking for individual paired snips and where one value seems to be associated with having a higher educational attainment than another value, and then there's inferential work can be done on top of that to try and identify genes, though that starts to get very very complicated. There's I think one other important

thing to say about this overall process. By the way, I don't think you used. This is called juas or association study. Is this process of searching for snips associated with and so we're now doing this process for all of the many human traits that we discovered were heritable fifty years ago, using twins and siblings and adopt these and all that kind of stuff. And it's interesting that we're able to do this now, and it may well turn out as time goes by that we learn important

things from doing this. But it's not surprising for all these heritable traits that we're able to find snips that are associated with them once we knew that intelligence was heritable. Another way of saying that is to say, well, there are differences in DNA that are associated with intelligence. We knew that was true, and so a lot of modern snip finding, from my point of view, is a matter

of confirming what we already knew. It's finding out the same things about heritability that we already knew from twins and siblings and families. I think there's a tendency to sometimes that, even now that people have gotten used to the idea that behavior is broadly heritable, to make the same mistake you were suggesting of thinking, wow, now that we're finding out that there are actual little bits of DNA that are associated with these behaviors, that must really

be fixing it. You know that we're really finding the education genes or more and more commonly, the IQ genes here, and I personally don't really think we are. I think it's safe to say the jury is still out And I think there are a lot of people who think that at least we're at the beginning of a road that's going to end up with a actual genetic biological understanding of something like educational attainment. I myself am quite

a bit more skeptical. But you would never you could never do without the socialization process in this no matter what is found. If you want to increase educational team. Even if it turns out that some people have greater genetic potential for the ultimate heights of learning and rate of learning, et cetera, et cetera, that still doesn't mean that we should provide the most challenging opportun coortunities for everyone, right, Oh, of course not so. I think that kind of gets

missed sometimes in these discussions. Is you know, we can get so lost in the weeds that so like so what you know, like, you know, what's the practical implication here? Now, some people have written some thoughtful books about a genetic understand how genetically informed understanding of school could lead us to teach an individualized learning for different people, et cetera, et cetera. And I think there are some thoughtful things out there about that, but still doesn't get rid of

the teaching part. No, of course not. I know you say, of course not, but I do think that is missed in somebody's well yes, no, and no. I mean I say, of course not by way of agreeing with you. But it it's an incredibly difficult and complicated problem. I mean, I've spent my entire professional life trying to think about exactly what it means that our genes might be related

to how much education people wind up obtaining. And you know, if you put me on the spot and say, okay, you've got three minutes explain exactly how that works, I'm not sure I could do it. And it's a very very deep and difficult theoretical problem. When you have a problem like that, I think what happens is that the two poles of the problem, the two easy ends of it,

become magnets for people. And you find people saying, oh, yeah, we got the genes, you know, and people are just born that way, and some people are born smarter than others. And then you have people on the other side saying, how could you say such a thing that the genes have something to do with educational attainment, That that's determinism and et cetera, et cetera, et cetera, and want to argue that genes must have nothing to do with it, and neither of those two polls is ever a good

answer good. I would not want it to be the case that our intelligence was one hundred percent determined by either the environment or one hundred percent determined by our genes. Either situation would really suck if you think about it, right, I mean, then you would have no free will either way. Kind of. But people don't realize is that the way the reality of the world is is actually pretty neat

in a way. There is something that it means to be you, but there's also a lot that you can do to construct yourself and become who you consciously want to be. And also, I want to say I abhore the process of the idea that someday we'll be able to, as early as possible, measure people's genes and then use that as a forecasting utility value to differentiate people into different tracks as early as possible based on their genetics. Now,

I really really do not advocate for that. I agree with you, Yeah, not just from like a there's a moral standpoint, but just from like a human potential standpoint. I'm not convinced that doing that would maximize Yeah, it would be. I mean, the fact is people think of it as something we could do off in some science fiction future. But the fact is we could do it today. About how we could do it today shows I think why it's morally wrong. Here's how you predict kids' school

performance from their genes. You look up their parents' IQ scores, and parents' IQ scores are really powerful predictors of children's IQ scores. I mean really much much, much better than anything we could do with genomic information. And much of the reason for why parents IQ scores predict kid's IQ scores are genetic. So why not just say, well, we should take parents who are really smart and give best resources to their children because they have the best genetic potential.

You can't do that because people have a right to make the best of what they are, regardless of your judgment of what their genetic potential is. I couldn't agree more. Maybe I don't know if this is plain Devil's out it be kid a little bit, But I want to ask you a question I just thought of. So if we agreed that the inhritability coefficient of a pt or population. And by the way, heartability is a population variable related variable,

and it has to do with individual differences. There's no other thing as a heritability within a person, just like there's such a thing as a cube within a person. And it also means that for me, the question what's the heritability of intelligence is a really bad question. Intelligence doesn't have a erritability. It's like a property of it that it carries around from place to place. The heritability of intelligence depends on the particulars of the situation in

which of the population in which that intelligence is measured. Absolutely, so that's one part of it. But so if we can agree that heritability is not a good proxy for the ability to change, then you've shown done research interests, a very interesting research showing that heritability coefficients are not

the same magnitude across social classes. Now, even if that is true, and I'm kind of playing table's advocate for a second, Even if that is true, and we already just concluded that ritable is not a proxy for the ability to change, then what's even the practical implication of your own findings in that regard? Do you know what

I'm saying, yes, it's funny. I mean, if I'm honest as somebody who's sometimes critical of people obsessing about what the heritability of this or that is, I do think it's hard to say exactly what it means that the heritability of intelligence, which is what that research is about, is different in some places than others. But I do think you can put meat on the bones of that finding.

And the finding is that the heritability of intelligence, and I should add it seems like it's in the United States is lower in poor people than it is in well off people, middle class and better people. Doesn't seem like that happens in Europe, which is the main other place that's been studied, probably because there's less economic and equality there, and especially educational inequality. And I frankly can't prove this. I think this is informed speculation about what

that might mean. A variant on a standard example for thinking about genetic differences. I suppose you have a bunch of seeds that are vary genetically for how tall plants are going to be, and you plant them in really excellent soil, and some plants wind up taller than others, and that they're all in the same soil, the same good soil, and some wind up taller than others, and that's genetic variation in the seeds. You then take the same handful of seeds or another handful out of the

same population and plant them in sand. Well, two things are going to happen. First of all, they're all going to be shorter, we all know that. But they're also going to be less varied because they're all going to be stunted. Even the seeds that had the genetic potential to produce tall plants in the good soil are going to wind up stunted. And of course if the soil is bad enough, they're not going to grow at all. So it makes sense that individuals need a reasonably supportive

and vironment in order to express their genetic variability. And if people are in an environment that doesn't permit them to seek out the environments that they can use to support, as you said, who they're going to become, well, then that's going to cut down on the variability. And with heritability as a way of describing variability, so you know,

I think that's what's going on. Then you can take a kid who has the potential to be a genius and raise that kid in an environment with a different family and crummy schools and a terrible neighborhood, and that kid is not going to be able to find the resources to help him or her become really, really smart. And so it's a leveler. I say the rest of this podcast, let's talk about the most controversial topics, because I think that's it feels right to transition into those now.

So when we talk about sees the cause of SES differences in this idea, you know, Charles Murray has the CTD of the cognitive elite as kind of being a reason. Now, it's a reasonable thing to say that there are IQ differences between different SES groups. Just to say that is reasonable, But to me, it seems to ignore all the you know, it kind of puts too much focus on this one variable, you know, when there are so many other variable one could pick any one variable and write a whole book

of assigned the key causal role to that barrier. It doesn't see intelligence as part of the network of good things that happen to people when they're in a successful society and have resources. It sees them as the cause for why they're in that position. In the first place. And you know, it brings us back to just everything we were talking about the beginning. That g is this property that exists inside people and causes them to express all those good things that happen to them. That's the

Bell curve basically. And like you say, I mean, it's not a I don't think that's a crazy idea or a evil idea particularly. I just think it's wrong. I just think it mischaracterizes the role that intelligence actually plays in life. It's not the inner causal agent that causes any more than health is to say. You know, like you say, you could talk about there's a health elite, right, not even health. We could add to this list any trait.

We could say aggression. Let's take aggression. I've seen some fabulous research come out recently by Daniel Nettell and others from an evolutionary point of you're showing just minor social economic changes you make that reduce the aggression level significantly. Now in some studies, I've seen their aggresion levels produced so much that there's no difference anymore between well SS and high SS. Once you make some minor system wide tweaks to a really unstable and harsh environment, that people

are living in. So one could make argument they are the way they are because they have low impulsivity, because

they have aggression. But if you instead view it as the smaller we're talking about as these are all outcome indicators kind of barometer, a barometer of what environmental experiences interacting with genes that we all have, that any of us could become in a way with certain environment Christians, that's a different way of thinking about it, right, Yeah, it's a much more complex way of thinking about it, and it doesn't locate all the causation in one particular variable.

So let's go to the most controversial topic. Let's go right there. Okay, race differences in IQ. Now, look again, it is not an unreasonable thing to say that there are race differences in average IQ scores between whites and blacks. That's just an observation fact. And that gap does not seemed to narrow in the past twenty five years. Okay,

I narrowed a little bit. It's not a topic I'm an expert on, but some of my common co authors, Jim Plann, dick nisbet Bill Dickens, who know more about that than I do, I think, argue very persuasively that it's down by a third over the last thirty four years. Okay, so it's down, but there's still exists. Way, it hasn't gone away. Okay, now there, and then there's the other question, what are the causal forces? Just we have the same discussion about sees Lyell and let's you know, we could

talk about group. Okay. The thing about this issue is that Okay, so first of all, we know that just because IQ is heritable, there's nothing in what we learn about the hritle bit of IQ that can be directly applied to understanding whether or not genes explain the difference

between blacks and whites. So we can have a whole discussion as we are having on this podcast, agreeing that yes, there is a genetic contribution to individual differences in IQ in the general population, and that doesn't have anything to say about whether or not to the extent to which genes explain differences between different groups. Now, do are we grid in that as well? Absolutely? So here's a question

I have is racist social construction. Does it make sense even in the first place, to look for genetic environmental factors that explain difference between whites and blacks in America. Well, I mean, I'm not sure I have the same You ask two questions, and I'm not sure I have the

same answer to both of them. The first one is race to social construction, and the second doesn't make sense to talk about genetic environmental great point, because one could be yes, the other one can be right yes as well. I'm a moderate sort of on that whole social construction business. And in some funny way, that's a question that people have argued about for so long, and it doesn't really seem very complicated to me. In a way. There are

a lot of things that we know are true. The human evolutionary story is a real thing, and we know a lot about where human beings came from and how they came out of Africa and how they spread around the globe over a very very long evolutionary time span. It's also the case that in more recent times, people who live together in certain parts of the world are

more genetically related to each other. People who live in Lithuania and think of themselves as Lithuanians are more like each other than they are like Japanese people who are like each other, and so it's not like the difference between Japanese people and Lithuanians. Is this imaginary social thing that we made up. There's biological reality, but the evolutionary story and the geographical sorting of people around the world is by and large continuous and dynamic. There aren't bright

lines dividing groups of people Lithuanians from Slovs. From those lines that we impose on that biological reality are yes, socially constructed. Now does that make them wrong? No? Does it make them useless? No? It makes them artificial boundaries that we impose on a very complex biological reality. So one more example, just to make the point that I was just thinking about. It's a kind of a trivial example, but I think it gets the point. Ski slopes are

very complicated things. They differ in slope, they differ in how many moguls they have, they differ in how long they are, they differ in how narrow they are, all sorts of things, and there are all sorts of ways we could think about the difficulty of ski slopes. But what do we do. We come up with yellow, blue, and black, and we classify ski slopes as though there

were just three kinds yellow, blue and black. Now, if we ask, are there really three kinds of ski slopes in the world and only three kinds of ski slopes? Of course not right. Ski slopes are much more complicated than that. But sometimes under some circumstances, it's useful to break them up in these those groups, as long as we remember that the three part and the exact borderline between yellow and blue is not given by nature. That's

something that we do. So that's the answer to that A too long answer to the is it a social construction question? Should I go on to looking for intelligence difference? No, because I want to talk about the nittigree of this now again. I refer people for a really nuanced review of the current state of evidence. I refer people to read Nicholas mcintosha's second edition of IQ and Human Intelligence.

He's a whole chapter on this, and I was say, in a nutshell, after reviewing carefully all the evidence, there is no good evidence that genes whatsoever play a role in explaining differences between blacks and whites. The perspective I'm coming from is, you know, education is such a crucial gateway to opportunities in life. When I see the evidence that blacks and whites differ on average in educational attainment

standardized test scores. Things like this, I immediately go into like intervention mode, like I want to know, like what are the whole causal factors? What are the things we can do to change the culture, perhaps in some ways to motivate show people who are in low sees environments, for those who are difficult circumstances, that there's a future for them. And all these factors have been shown to help reduce the gap, little by little, lots of little

factors add up. Now the question is, even if they don't all add up one hundred percent? To explain the differences, I have this so what question? And Charles Murray was recently on the Sam Harris podcast As You Know, and Sam Harris asked him, you know, the so what question? And the only answer Charles Murray had to the purpose of finding out detaining the genetic information was implications for college entrants for you know, And I don't feel like

I understood whatsoever. I still left that podcast not understanding the so what question? Can you convince me at all that there's any practically meaningful societal other than just knowledge for the sake of knowledge of knowing that even like five percent of the differences between different groups can be not one hundred percent deterministic but are influenced by gene differences.

I have, again, I've complicated feelings about this. I'm I'm not one who would think that there's ever a valid scientific reality out there that we shouldn't go to because the consequences are bad and we don't see the utility. I mean, And in addition, as a practical matter, I think it's generally impossible to keep those genies in the bottle anyway. And if it's true and real, sooner or later it's going to out and everybody's going to know

it anyway. So and I guess I do think that for something that is on a sound theoretical footing and has real meaning and it's true, we should go there. And so I actually don't like the defense against genetically based race differences, which says this is a bad thing there, nothing good can come of it. Why should we know it? I mean, if it were true and if it made sense, and I don't think it makes sense, it's going to

happen anyway. By the way, I agree, I don't think that knowledge should be censored and I encourage more research on whatever someone wants to research. So I want to be very clear about that. My question, the so what question I'm asking is not the so what in terms

of like we shouldn't be doing the research. It's like, you know, the so what is like I've been asking so what a lot today, Like when we talked about the fact that i Q might be heritable, Well, how does that help me, as an individual think about what is possible within me? So my question is people act as though it'd be so forbidden if we found that some small proportion of race differences was correlated with genetic differences. But I'm trying to say, is even if we gosh

forbid found that, would that change change? I think would be really bad. Frankly, tell me more, because what would it? I mean again, I ultimately don't think this concept of genetically based differences between groups makes any sense, and it makes me nervous about talking about the consequences as though

it did make sense. But if we really knew that an entire group, the only thing I can imagine that meaning that statement meaning is that this group of people has lower IQ than that group of people, and there's nothing you can do about it. That's not what that would mean, right, Well, I think would If it doesn't mean that, then what sense does it make to say that the mean difference is based in the genes, right, If you can make it go way environmentally, then it

wasn't based in the genes in the first place. We really don't know that because of the genes an individual has that there's a limitation to what their IQ could be under any possible environment that we could expose them to. We don't know that short of them having some major

genetic disorder or something. And actually, I think that's a very important idea that it's very important that we know basically at asolutely nothing about the biology of why some people are smarter than others from a genetic point of view, because that really means that, as a matter of potential, our malleability is practically unlimited. And it brings us back to your original point that knowing that intelligence is heritable

does not put a limit on the malleability of that intelligence. Right. So, if what you said is true that the heritability of IQ is independent of the malleability of IQ, it's not the case that printing out my genome when I was born, gives you information that allows you to say that it's impossible that the world might have turned me into a

Nobel Prize winner much smarter than I actually am. And what we know about group differences in intelligence is that the magnitude of them is smaller than we absolutely know the malleability of intelligence to be in a number of ways, that when children are adopted out of poor homes into well off homes, the amount of change in their IQs is larger than the modern difference between blacks and whites.

The difference in the average iq of white people in the United States now and white people in the United States in nineteen fifty is larger than the difference between blacks and whites. So that we know, we know that average IQs are malleable well within the range of that difference. So knowing that, I simply don't see how it makes sense.

And you know, and when you were talking before about mining to turnout, well that it's just a few percent, just five percent, the whole percent thing, which is problematic enough at the individual level, it makes no sense at all at the group level. There is no group heritability coefficient that can come out to be equal to a particular number. If you go look at the articles the very by the people who really believe in genetic differences between the races, and in their own way take a

very scholarly and serious approach to the problem. It's not like they're listing studies and saying this one shows that it's twelve percent heritable, and this one shows that it's twenty eight percent heritable. Because there's no mathematical model to produce those numbers, the idea of the group difference being x percent heritable doesn't make sense in terms, there's no

quantitative genetics that produces those numbers. One more and then I'll stop, because I think this is the key important idea. You know, if it made sense that groups might differ in complex behavior, that the groups like different complex behavior in a way that's partially in some percentage, wouldn't it be the case that there were other group differences in behavior that we'd already figured out. You know that Japanese people are more introverted than people from the Dominican Republic.

Oh yes, and we've done some research and it turns out that's genetic. On the other hand, you know, Chinese people are better table tennis players than people from Kenya, And hey, how do you like that we did the research and that turns out to be environmental? Right, there's not a single complex human trait that has ever been shown to be genetic or environmental in any proportion, because to me, it's not really an empirical question. The empirical

question is how malleable are these things? And to the extent we know they're malleable, and things are way more malleable than we think, to the extent they're malleable, we can't prove that they're fixed genetically. Eric, I love that point. I want to end on the point that the idea of how niable things is a separate issue. I think that's a theme of this whole discussion today, separate issue from what's the herod ability? Explit good? And I want to leave for the last thirty seconds on a very

personal note. I don't want to belabor it, but I would be remiss not to say that I personally saw what it was like to grow up with people expecting very low things from you because of your IQ score, because of a learning disability and auditory learning disability. I had a very low measured IQ and that really I was labeled a slow learner, and it really did affect how people looked at me and treated me, and then it affected my own self esteem and then what I did.

And it took a couple of people to really believe in me and kind of look past the labels before I was inspired to see what I was capable of achieving. So I want to just say that some of these researchers might want to spend some time digging more into different perspectives. I look forward to reading your book. It looks fascinating. Thank you so much for such an interesting chat today. Okay, good, that was a pleasure. Thanks very much. Thank you for the chat. Have a good day. Okay, yep,

I'll be in touch. Bye bye. Thanks for listening to The Psychology Podcast with doctor Scott barrk Kaufman. I hope you found this episode just as thought per booking and interesting as I did. If you'd like to read the show notes for this episode or hear past episodes, you can visit the Psychology Podcast dot com.