Turkheimer's Projects: Genetics and Human Agency | Charles Murray's “Human Diversity”

Posted at 14:51h in Uncategorized by Eric Turkheimer 12 Comments

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.

Scroll to Top