Probing the biological basis of certain traits ignites controversy. But some scientists choose to cross the red line anyway.
Growing up in the college town of Ames, Iowa, during the 1970s, Stephen Hsu was surrounded by the precocious sons and daughters of professors. Around 2010, after years of work as a theoretical physicist at the University of Oregon in Eugene, Hsu thought that DNA-sequencing technology might finally have advanced enough to help to explain what made those kids so smart. He was hardly the first to consider the genetics of intelligence, but with the help of the Chinese sequencing powerhouse BGI in Shenzhen, he planned one of the largest studies of its kind, aiming to sequence DNA from 2,000 people, most of whom had IQs of more than 150.
He hadn't really considered how negative the public reaction might be until one of the study's participants, New York University psychologist Geoffrey Miller, made some inflammatory remarks to the press. Miller predicted that once the project turned up intelligence genes, the Chinese might begin testing embryos to find the most desirable ones. One article painted the venture as a state-endorsed experiment, selecting for genius kids, and Hsu and his colleagues soon found that their project, which had barely begun, was the target of fierce criticism.
There were scientific qualms over the value of Hsu's work (see Nature 497, 297–299; 2013). As with other controversial fields of behavioural genetics, the influence of heredity on intelligence probably acts through myriad genes that each exert only a tiny effect, and these are difficult to find in small studies. But that was only part of the reason for the outrage. For decades, scientists have trodden carefully in certain areas of genetic study for social or political reasons.