Charles Murray’s Real Talk on Biological Differences
If biology is destiny, as a heaving body of literature increasingly demonstrates, no one, it seems, has bothered to tell the mandarins who dictate discourse in the social sciences. At least not until now.
In Human Diversity: The Biology of Gender, Race, and Class, the acclaimed researcher and polymath Charles Murray examines and condenses hundreds of peer-reviewed studies on the links between biology, race, gender, and class and contends that “the social sciences have been in the grip of an orthodoxy that is scared stiff of biology.” While geneticists have made unfathomable strides, they’ve been all but ignored by mainstream sociologists, psychologists, economists, and political scientists.
A decorated scholar at the American Enterprise Institute (disclosure: where I serve as an adjunct fellow), Murray’s previous groundbreaking books have produced nearly as much controversy as praise, especially his explosive The Bell Curve, written in 1994 with the late psychologist Richard Herrnstein.
But Human Diversity isn’t a flamethrower, unlike some of Murray’s earlier works. If you’re “looking for bombshells,” he writes at the outset, “you’ll be disappointed.” While he explores key differences across gender, race, and class, he pointedly “reject[s] claims that differences among groups have any relevance to human worth or dignity.”
Instead, Murray has carefully marshalled and curated an extraordinary range of psychological, biochemical, neurological, and other social science studies of human development in the service of ten key propositions, all of which, in his telling, reflect a broad consensus across disciplines.
Made possible by remarkable advances in genome mapping and computing, these propositions include, most prominently, the notions that: sex differences in personality differ most widely in gender-egalitarian cultures; women worldwide have advantages in verbal ability and social cognition and are attracted to people-centered vocations, while men exhibit superiority in visuospatial ability and favor things-centered jobs; sex differences in the brain are coordinate with sex differences in personality; human genetic distinctions correspond to race and ethnicity; class structure can reflect genetic differences; and the shared environment plays a limited role in explaining personality.
In considering personality differences, one key question in the literature involves whether and how to aggregate various individual differences, such as divergences between, say, how outgoing and emotionally stable two sets of populations are. While there is overlap between these traits, they’re sufficiently distinctive as to warrant some form of combination of their sex-specific differences.
By way of analogy, Murray explains, imagine Springfield, a town located 35 miles west and 35 miles north of Shelbyville. The distance between the two would be more than 35 miles but less than 70 miles and would instead involve a Pythagorean calculation of the hypotenuse of the triangle formed by the relevant points. And if we consider that Springfield is located at sea level while Shelbyville is a mile high, that elevation difference would also need to be factored in.
Drawing on an extensive survey of studies, Murray finds that these aggregate differences between sexes widen in countries that are more gender-egalitarian. Numerous studies have found that countries with greater gender discrimination, such as Congo, Egypt, and Pakistan, functionally suppress these differences while more equal societies, such as Western Europe and especially Scandinavia, are replete with them. Both personality traits, including extraversion, conscientiousness, and agreeableness, and relative performance in verbal and mathematical fields diverged among sexes in these countries in direct proportion to the level of equality in each.
Explanations for this somewhat counterintuitive trend include the tendency of women to enter STEM fields in Arab and Muslim countries, where a high proportion of young men are shopkeepers or study in religious seminaries, as well as the ability of women in more open societies to pursue what they desire. As Murray puts it, in Scandinavia and other highly equal countries, “both sexes become freer to do what comes naturally.”
Murray also uncovers the indomitable role of testosterone and estrogen in promoting the sex-divergent personalities of boys and girls, even among babies. These hormones regulate everything from social cognition to impulse control to risk aversion to visuospatial ability, and their relative presence in the prenatal environment has profound, even dispositive effects on human development.
“When we got those results,” Simon Baron-Cohen, a groundbreaking British clinical psychology researcher, said of a revealing experiment of the effect of testosterone on toddlers, “I had one of those strange feelings, like a shiver down the spine. A few drops more of this little chemical could affect your sociability or your language ability, I found it extraordinary.”
Murray also wades cautiously into the realm of racial and ethnic differences, or as he more politely and accurately labels them, differences among ancestral populations, which recent genomic research has affirmed. Specifically, a landmark 2008 study of over 600,000 genetic variants found statistically significant clustering of “ancestry coefficients” that roughly correspond to North and South American, European, African, East Asian, Central and South Asian, and Oceanian populations.
These genetic differences correspond to phenotypic variations, such as a greater prevalence of anemia in people of African descent, higher rates of diseases like Tay-Sachs among Ashkenazi Jews, and respiratory adaptations by Tibetans, Ethiopians, and other high-altitude populations, all of which squares with common sense and lived experience. Murray is careful to note, however, that “genetic differences across populations is small compared to the variation within populations.”
Finally, Murray explores the relationship between genetics and class, arguing generally that genetics account for the vast majority of socioeconomic outcomes in the Western world. Specifically, on the nurture-nature spectrum, Murray surveys studies, most based on identical twins, that overwhelmingly found cognitive repertoires genetically inherited.
Ultimately, “racism and sexism still play a role in determining who rises to the top,” Murray concedes, “but that role is not decisive.” He also pours cold water on the epigenetics craze—the notion that traumatic external events can reshape DNA itself—by highlighting meta-studies undermining the media’s most lurid epigenetic reporting.
As compelling and meticulous as his work is, Murray will likely continue to struggle to persuade his harshest critics. For instance, his focus on the chemical inevitability of hormones can cut both ways. After all, if hormonal chemistry is destiny, then why not simply offer testosterone to transgender men or nonconforming individuals who identify as male to assist them in transitioning? Even if the effects of these hormones are much more keenly felt in the prenatal and early developmental stages, they continue to serve as powerful gender equalizers even later in life.
In addition, his analysis of class and socioeconomic status relies heavily on cognitive repertoires, which in many cases serve as proxies for IQ. But, as with the furious backlash against The Bell Curve, IQ-centric theories are unlikely to generate sympathy from certain readers on the left skeptical that they are administered fairly, as Murray candidly acknowledges.
But Murray need not persuade everyone in order for his magisterial book to be a success. As he observes, we’re on the precipice of an explosion in biology-based analyses of critical issues that will compel “the social sciences [to] come to terms with genetics.” Human Diversity more than ably lays the groundwork for this nascent debate.
Michael M. Rosen is an attorney and writer in Israel and an adjunct fellow at the American Enterprise Institute.
