Gideon Lewis-Kraus writes:

[Kathryn Paige] Harden understands herself to be waging a two-front campaign. On her left are those inclined to insist that genes don’t really matter; on her right are those who suspect that genes are, in fact, the only things that matter. The history of behavior genetics is the story of each generation’s attempt to chart a middle course. When the discipline first began to coalesce, in the early nineteen-sixties, the memory of Nazi atrocities rendered the eugenics threat distinctly untheoretical. The reigning model of human development, which seemed to accord with postwar liberal principles, was behaviorism, with its hope that environmental manipulation could produce any desired outcome. It did not take much, however, to notice that there is considerable variance in the distribution of human abilities. The early behavior geneticists started with the premise that our nature is neither perfectly fixed nor perfectly plastic, and that this was a good thing. They conscripted as their intellectual patriarch the Russian émigré Theodosius Dobzhansky, an evolutionary biologist who was committed to anti-racism and to the conviction that “genetic diversity is mankind’s most precious resource, not a regrettable deviation from an ideal state of monotonous sameness.”

The field’s modern pioneers were keen to establish that their interest lay in academic questions, and they prioritized the comparatively clement study of animals. In 1965, John Paul Scott and John L. Fuller reported that, despite the discernible genetic differences among dog breeds, there did not seem to be categorical distinctions that might allow one to conclude that, say, German shepherds were smarter than Labradors. The most important variations occurred on an individual level, and environmental conditions were as important as innate qualities, if not more so.

This era of comity did not last long. In 1969, Arthur Jensen, a respected psychologist at Berkeley, published an article called “How Much Can We Boost IQ and Scholastic Achievement?” in the Harvard Educational Review. Jensen coolly argued that there was an I.Q. gap between the races in America; that the reason for this gap was at least partly genetic, and thus, unfortunately, immutable; and that policy interventions were unlikely to thwart the natural hierarchy. The Jensen affair, which extended for more than a decade, prefigured the publication of “The Bell Curve”: endless public debate, student protests, burned effigies, death threats, accusations of intellectual totalitarianism. As Aaron Panofsky writes in “Misbehaving Science,” a history of the discipline, “Controversies wax and wane, sometimes they emerge explosively, but they never really resolve and always threaten to reappear.” [Continue reading…]