Charles Murray's "Human Diversity"

Charles Murray's "Human Diversity"

Charles Murray’s new book, Human Diversity, is out today. I will write a few blog posts about it over the next few weeks.

First, a general note about how I am going to approach the book. It will come as no surprise to anyone who knows anything about Murray’s point of view and mine that I disagree with pretty much everything in it. There are parts of it that I find reprehensible. Nevertheless, the book is based on Murray’s reading of scientific data, it is carefully argued, and I think it needs to be rebutted in a serious way. Scientific racism infuriates me, and I have in the past been goaded into charges of “pseudoscience” when confronted with Murray’s claims about race; I am going to avoid doing that here. Those of you who are infuriated by claims about biologically fixed gender differences in behavior, or biological explanations of class differences, will find plenty to enrage you in the book.

I think there are several reasons to avoid outrage in responses to the book. One that happens to pertain to me is that my ideas and research figure in the narrative, and Murray treats my work with respect even as he disagrees with it, which I acknowledge and appreciate. (Looking ahead, in the section on polygenic scores he sets up a “Turkheimer-Plomin” debate, and while conceding that in the middle rounds I am ahead on points, declares me the loser anyway, based on scientific advances that he is sure are going to occur in the next decade. More on that later.)

The more important reason to remain calm in the face of Murray’s assertions of biologically fixed differences across gender, class and race is that outrage only feeds into the scientific right’s preferred narrative about this subject, which is that most scientists recognize that the hereditarian position is correct, but refuse to admit it either because they are blinded by their own liberal prejudices, or cowed by oppressive SJW culture on today’s campus.

This is the stance Murray adopts in the Introduction. He says there is an orthodoxy in the Academe, consisting of three tenets: Gender is a social construct, race is a social construct, and class is a function of privilege. Any discussion of the biology underlying these things, he asserts, is met with contempt and exclusion from the community:

It is possible to survive on a university campus without subscribing to the orthodoxy. But you have to be inconspicuous, because the simplistic version of the orthodoxy commands the campus’s high ground. It is dangerous for a college faculty member to say openly in articles, lectures, faculty meetings, or even in casual conversations that biology has a significant role in creating differences between men and women, among races, or among social classes. Doing so often carries a price. That price can be protests by students, denial of tenure-track employment for postdocs, denial of tenure for assistant professors, or reprimands from the university’s administrators.

This picture of the PC-dominated college campus where biology is anathema is repeated so often that it is easy to assume that it must be true, but it has never made any sense to me. Are the social sciences really dominated by environmentalists? Galton, who more or less invented social science, was a hereditarian. Most of the major early theorists of genetics and intelligence were followers of Galton and hereditarians. (Murray cites John Watson, of all people, whose radical behaviorism is about as uninfluential right now as it is possible for an idea to be.) The dominant social scientists of the middle part of the century, the Cattells and the Eysencks, were hereditarians. Arthur Jensen had a pretty good run. Today, behavior genetics is a well-established part of most psychology departments in the country. Robert Plomin is among the top 5 most cited living psychologists, and was awarded the American Psychological Association’s highest award for lifetime achievement. Modern psychiatry is completely dominated by genetics and neuroscience. Do you have the sense that GWAS of behavior has been suppressed lately? You can’t get away from it. Neuroscience, if anything, is even more dominant that genetics in the modern behavioral sciences. People who still try to deny that genes or brains have anything to do with human behavior are the outcasts, not the behavior geneticists and neuroscientists.

So what’s the problem? According to Murray, it isn’t that scientists are afraid of behavior genetics generally, it is that they are timid about applying the science to groups of people.

Call it the sameness premise: In a properly run society, people of all human groupings will have similar life outcomes. Individuals might have differences in abilities, the orthodoxy (usually) acknowledges, but groups do not have inborn differences in the distributions of those abilities, except for undeniable ones such as height, upper body strength, and skin color. Inside the cranium, all groups are the same. (emphasis mine)

(replaced repeated quote 3:45 1/28)

It’s true, of course, that one can get in trouble for announcing that biology plays a role in differences between groups of people, but I think Murray gets the reason wrong. It isn’t about individuals and groups, that somehow you can get away with saying that biology determines the behaviors of individuals, but get in hot water if you say the same thing about groups. My whole career, dating from my first serious paper about genetics in 1991, I have argued that groups are just collections of individuals, and the same scientific explanations of why individual people act as they do necessarily apply to the average behaviors of groups of people. If individual women are compelled by their biology to prefer social work over engineering, then so it will be for women in general, and there is no way for anything– social or biological– to have an effect on groups of women, other than by affecting one woman at a time.

So why is it that no one will ask you out to lunch at the faculty club if you announce that poor people as a group are poor because they have genes that make them poor? It is because you have misunderstood the nature of the relationship between genetic and behavioral differences. We have recently been reminded that income is heritable. Everything is heritable. But what does the heritability of income mean about the explanation of why some people are poor and some people are rich? Here is what it doesn’t mean: It doesn’t mean that there exist genes which, if you are unlucky enough to possess them, guarantee that you are going to be poor, or even predispose you to be poor in any kind of deterministic causal sense. My point of view in a nutshell: Quantitative heritability (and, as we will see when we get into sex and gender, biological differences more generally) does not imply genetic determinism.

So the reason you get ostracized when you announce that some group has low test scores because of their genetic inferiority is not because you are being discriminated against for having the courage to take what everyone knows is true for individuals and apply it to groups; it is because you are misinterpreting what it means that IQ is heritable in the first place. It would be just as wrong to say that your SAT scores are higher than mine because you have genes that make them higher.

So the endless whining on Twitter about the poor oppressed proponents of the HBD movement is not about group differences, it is about genetic determinism. Almost all modern behavioral scientists are fine with the idea that genetics and biology have to be taken into account in understanding human behavior. Most of those same scientists, however, are wise enough about what they are doing to know that the current state of the science does not permit us to derive behavior from biology; some of us, and here there is room for disagreement, believe that it will never be possible to do so, and that the inexorable progress of science offers no easy way out.

Eric Turkheimer

Eric Turkheimer is the Project Leader for the Genetics and Human Agency Project. Eric is a clinical psychologist and behavioral geneticist. For thirty years he has been involved in empirical and theoretical investigations of the implications of genetics for the genesis of complex human behavior. Current projects include understanding the interaction between socioeconomic status and the heritability of intelligence, and philosophical analysis of the ethical status of work that purports to demonstrate biologically based differences in behavior among racial groups.

  • John Clarke
    Posted at 16:51h, 29 January Reply

    I don’t know anyone who is a genetic determinist. A white person isnt “determined”” To be smarter than a black person. It’s simply that the genes which influence high intelligence are more prevalent in whites than blacks. Therefore in a society such as the United States it’s inevitable that there will be a gap in IQ. What’s your explanation for a persistent 15 point gap? We now have admixture studies which indicate that the higher the European ancestry in an African-American the higher the IQ. The results are linear which is inconsistent with a cultural explanation.

    • Jlrinc
      Posted at 11:39h, 15 June Reply

      This might be the dumbest thing I have read in years. Specifically which Gene’s that influence intelligence do Europeans have more of. Please enlighten us with your encyclopedic genetic knowledge because you seem privy to information that no other geneticist in the world has. Or maybe it’s just that you’re talking out your ass.

  • John Clarke
    Posted at 17:02h, 29 January Reply

    I think it’s a little simplistic to say the university world isn’t hostile to hereditarians. When David Reich wrote that when the genes that influence behavior and intelligence are found they will vary from race to race he was attacked even though he’s on the left. (He also said that he doesn’t expect “stereotypes” wouldn’t be confirmed. Lot of good that did him.)

    Maybe in a meeting of a psychologically department a hereditarian can say group differences in IQ have a genetic component but even then I doubt most who are up for tenure will.

  • Rick Frey
    Posted at 23:25h, 29 January Reply

    Saw an article about this book and figured there would be sites discussing it and found this place. Glad to find someone critical of the book as I don’t know much about it but as an educational researcher, I have a pretty good background in many of the issues addressed.

    First thing I appreciated was the wisdom of the call to not express outrage, but simply discuss the content. The two worst things happening in arguments today about important topics are faux outrage and blatant misrepresentations.

    Given the carefulness about avoiding outrage, I was surprised, however, by what even the most casual reader would recognize as a fundamental misrepresentation of the most basic idea of population genetics. As another commenter said, there is no one arguing for genetic determinism. Saying that Murray makes “assertions of biologically fixed differences across gender, class and race” misses the basic premise of population genetics that traits vary across populations. Height, hair color, eye color, etc. all vary across populations, so the differences cannot be fixed (i.e. locked in place) by genetics. This is either such a profound misunderstanding as to indicate the author doesn’t know anything about populations and genes or it’s an intentional mistake, ignoring the actual argument Murray makes so that they can argue against something obviously wrong.

    The next surprise was to see Turkheimer’s argument, “If individual women are compelled by their biology to prefer social work over engineering, then so it will be for women in general, and there is no way for anything– social or biological– to have an effect on groups of women, other than by affecting one woman at a time.”

    Re-write this sentence as Chinese women genetically determined to be shorter than US women and it’s easy to see how silly of an argument this is. Genes differ across groups, not all individuals have the same genes. There is a distribution of height of Chines women just as there is for US women. Even if you found a really tall Chinese woman, that wouldn’t change the fact that there are reliable differences between the groups, that the trait of height has a significant genetic component and that race/ethnicity is a reliable predictor of height in this situation.

    Given that this is the first critique of the book, Turkheimer could have picked any examples and the clearest arguments to “rebut the book in a serious way”. This first attempt, however, does the exact opposite.

  • Joe James
    Posted at 12:38h, 30 January Reply

    “Scientific racism infuriates me” How can science be racist? If it turns out that there is a non-trivial genetic component to group differences in intelligence then that’s the case. It’s not racist.

    People always bring up the Nazis. The Nazis were defeated 75 years ago. I don’t know if there were any polls of Americans at the time, but it wouldn’t surprise me the majority of white soldiers were what we call today “race realists.” Likewise, it wouldn’t surprise me (although I don’t know) that Churchill, Roosevelt and De Gaulle were also race realists.

    And the body count for Communists is much greater. So more people have died in the name of egalitarianism than hereditarianism.

    “So the reason you get ostracized when you announce that some group has low test scores because of their genetic inferiority is not because you are being discriminated against for having the courage to take what everyone knows is true for individuals and apply it to groups”

    If you and I had equally good parents and schooling and you wound up smarter than me it is most likely due to genes. That doesn’t make me inferior. What are groups except groups of individuals? As you noted, people who are not relatives but are close genetically tend to have similar IQs. Going out the gate I’d expect that groups would differ in intelligence and other traits.

  • Darin Johnson
    Posted at 17:48h, 31 January Reply

    I do not understand this comment. Maybe someone can help.

    “[Heritability of income] doesn’t mean that there exist genes which, if you are unlucky enough to possess them, guarantee that you are going to be poor, or even predispose you to be poor in any kind of deterministic causal sense.”

    I believe we agree that there exists a correlation between genes and income, i.e., income is heritable. Surely the suggestion is not that causation runs the other way — income causes genes. So we are left with only one other option: something else causes both genes and income. What would that mean? Or have I missed another option?

    Turkheimer’s followng comment — “Quantitative heritability… does not imply genetic determinism,” does not help me. In fact, it seems like a non sequitur or perhaps a straw man.

  • David Kane
    Posted at 22:16h, 01 February Reply

    You write: “Here is what it doesn’t mean: It doesn’t mean that there exist genes which, if you are unlucky enough to possess them, guarantee that you are going to be poor, or even predispose you to be poor in any kind of deterministic causal sense.”

    Would it also be true to say exactly the same thing about height? That is, would this be true?

    “Here is what it doesn’t mean: It doesn’t mean that there exist genes which, if you are unlucky enough to possess them, guarantee that you are going to be short, or even predispose you to be short in any kind of deterministic causal sense.”

    My sense is that this would be false, that there are genes which “guarantee that you are going to be short, or even predispose you to be short.” But I am not a geneticist! Just here to be educated.

  • Matt Ball
    Posted at 23:19h, 01 February Reply

    Thanks for this post.

  • Joe James
    Posted at 14:00h, 02 February Reply

    If there are genes which “influence” intelligence and Group A has more of them than Group B, then a classroom of A’s will be smarter than a classroom of B’s. This is true even if Joe from Group A is less intelligent than Fred from Group B.

    I find it odd that Dr. Turkheimer considers this controversial.

  • Nick Hel
    Posted at 12:50h, 02 March Reply

    Hi everyone,
    I have a couple of honest questions I’m puzzling with (bear with me)::

    * Let’s say 2 unrelated people from Mozambique (average IQ of MZ is 64) migrate to Europe.
    * They meet in Europe and have a child which benefits from European healthcare: proper nutrition, medical care and basically the same healthy environment as any other European fetus.
    * This child will go to European daycare and school and have the same early-life education. The only main difference will be the home environment (2 low IQ parents).
    * From what I’ve read in most cases the migrant child will (at the age of 8 already) still have lower average IQ scores than his European classmates, but be quite a few points higher than both his parents.

    My assumptions are::
    * The initial low IQ of the parents (64) will in large part be due to environmental factors such as generations of undernourishment in Mozambique, that over time probably switched on and off certain genes in their ancestry that are relevant in explaining the low IQ. The historical environment basically affected the genes in some way.
    * As the child is now born in a more beneficial environment, some of these genes are switching back to enable a higher IQ, but the effects cannot be reversed in one generation. The child is unfortunately still going to have a lower average IQ score in part due to the home environment and in part due to the inherited genes.
    * However, if the migrant child has a child of his own, the IQ increase will continue across generations, eventually almost entirely closing the genetic gap between the migrant child and European child. The only gaps left would be environmental.
    * A way to increase this transition towards higher IQ would thus be to promote or somehow encourage inter-racial marriages (which from what I read causes the biggest increase in IQ in migrant children). The genetic component for IQ differences in populations is thus real, but with enough time it can be overcome.

    Are these assumptions plausible? Have they been refuted or proved in some way?
    I’m really just trying to understand the issue (I don’t have a scientific background).

    Another crude example could be: a significant number of Pakistani UK residents marry their cousins, which causes genetic issues and congenital birth defects (and low IQ). If you were to take IQ scores from both populations (English ancestry or Pakistani ancestry), you will find that the scores on average are different between the populations, and that the genetic (dysgenic) component is very clearly relevant, no? The environment (detrimental mating habits) is thus causing genetic differences in IQ across populations.

    To me the most likely scenario is that IQ is influenced in part by genes, and in part by environment, and both influence each other to some degree. But the genetic gap could technically, in part, be overcome in a few generations by encouraging good mating habits and interracial marriages.

    Does this make sense? I’m not asking whether or not this is socially desirable, I’m not making a case for certain policies, I’m just wondering if biologically the reasoning is sound?

    Thanks for reading.

  • Michael R. Jackson
    Posted at 20:57h, 03 March Reply

    For an analysis of some of the many flaws in Murray’s book, see the detailed review at the following link:

    Nick–While the cultural characteristics you impute to Mozambicans and Pakistanis may not be entirely accurate, I think you make an excellent point. There is no clear dividing line between nature and nurture, heredity and environment, for exactly the kinds of reasons that you point out. Genes produce behavior only in and through environmental interactions; and environment influences behavior not only directly but also indirectly through developmental experiences, nutrition, infiltration of toxins, etc., that alter gene expression. “Race science” advocates cite reams of data, often from problematic studies; but even when the data are based on high quality research, the arguments that are then made to transform those data into demonstrations of genetically based superiority and inferiority generally rely on bogus assumptions about the definition, separability and quantification of “genes” and “environment.” No careful researcher takes these kinds of argument seriously, and I believe that this is what Eric is getting at in the above post.

  • Human diversity – Roberto Colom
    Posted at 07:01h, 17 April Reply

    […] primero. Los comentarios críticos a ‘Human diversity’ del segundo se pueden encontrar en su site. La confianza de Murray y Plomin en las puntuaciones poligenéticas es sacudida por Turkheimer: […]

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