taboo "genetics"

Nature | 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.

At the root of this caution is the widespread but antiquated idea that genetics is destiny — that someone's genes can accurately predict complex behaviours and traits regardless of their environment. The public and many scientists have continued to misinterpret modern findings on the basis of this — fearing that the work will lead to a new age of eugenics, preemptive imprisonment and discrimination against already marginalized groups.

“People can take science and assume it is far more determinative than it is — and, by making that assumption, make choices that we will come to regret as a society,” says Nita Farahany, a philosopher and lawyer at Duke University School of Law in Durham, North Carolina.

But trying to forestall such poor choices by drawing red lines around certain areas subverts science, says Christopher Chabris of Union College in Schenectady, New York. Funding for research in some areas dries up and researchers are dissuaded from entering promising fields. “Any time there's a taboo or norm against studying something for anything other than good scientific reasons, it distorts researchers' priorities and can harm the understanding of related topics,” he says. “It's not just that we've ripped this page out of the book of science; it causes mistakes and distortions to appear in other areas as well.”

Here, Nature looks at four controversial areas of behavioural genetics to find out why each field has been a flashpoint, and whether there are sound scientific reasons for pursuing such studies.