Xing Wu
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When Donald Trump cited genetics at a campaign rally in Minnesota in September 2020, commentators were quick to link its language to early 20th-century eugenics and Nazi science. “You have good genes, you know that, don’t you? Trump asked his almost all-white audience. “You have good genes. A lot of it is about the genes, isn’t it, don’t you think so? The implication was that, because of his race, his crowd was genetically distinct and superior to the black and brown immigrants that Trump has consistently denigrated and targeted with the policies of his administration.
This perspective, explicitly endorsed by some members of the political far right today, was once the dominant scientific view. Today, however, most scientists don’t take the idea of biological races seriously, in part thanks to Richard Lewontin, an evolutionary biologist at Harvard University who died in July at the age of 92. Lewontin made a name for himself in the 1960s, when he demonstrated using populations of wild fruit flies that individuals of a species are far more genetically diverse than scientists previously imagined. .
In 1972, Lewontin took his interest in genetic diversity in an explicitly political direction when he published an article demonstrating that only about 6 percent of human genetic variation exists between conventionally defined racial groups; the rest is in these groups. By studying how alternate versions of particular blood proteins – encoded by subtle variations of the same genes – were distributed across the human population, he was able to determine how much genetic overlap exists between racial groups.
If, for example, all whites were found to have type A blood and all blacks type B, the idea of genetically distinct racial groups would have been partially validated. But if half of the people in both groups had type A blood and the other half had type B blood, all the genetic variation would exist within the groups, not between them. Reality, Lewontin found, was much closer to the latter scenario. More recent experiments with a wider variety of genes validated Lewontin’s findings.
He concluded the 1972 article with a statement that would sound shockingly political in today’s scientific journals. “Human racial classification has no social value and is positively destructive of social and human relationships,” he wrote. “Since such a racial classification is now considered to have virtually no genetic or taxonomic significance either, no justification can be offered for its maintenance. The article was foundational – according to Google Scholar, it has been cited over 3,000 times – and is a major pillar of the aphorism “race is a social construct”.
“The idea that there was more variation within a group than between groups is old. It has been around for decades, ”says Jonathan Marks, professor of anthropology at the University of North Carolina at Charlotte. “What Lewontin did was put numbers on it. And it was very powerful.
Since the 1970s, new technologies have dramatically changed the landscape of genetics: Large-scale genomic studies have changed the way scientists understand the relationship between genes and behavior. “Lewontin was far-sighted by anticipating that with major public investment in genomics, genetics would take center stage in trying to explain disease, as well as, increasingly, social behavioral traits,” says Sandra Lee , professor of medical humanities. and ethics at Columbia University. As the power and sophistication of genetic technologies continue to grow, Lewontin’s work remains remarkably current.
One of Lewontin’s great scarecrows was his Harvard colleague EO Wilson, who held strong and influential views on the role of genetics in determining social behavior in animals and humans. With his 1975 book Sociobiology: the new synthesisWilson popularized the idea that behaviors ranging from altruism to aggression to sexual mores can be best explained by reference to evolutionary pressures. Lewontin believed Wilson unwarrantedly assumed – largely on the basis of animal research – that many human behaviors and characteristics, from creativity to conformity, must have been selected over the course of the species’ evolutionary history. . Lewontin argued that this idea represented just one more resurgence of the regressive belief that biology was fate, which he said had been used to solidify social hierarchies for centuries.
