Sir

Why study possible links between race, gender, genes and intelligence? In their Commentary (Nature 457, 788–789; 2009), Stephen Ceci and Wendy M. Williams's response seems to be that it provokes good scientists to sharpen their critique of the poor science of those who ask that question, and that this advances the field. I agree; when, in the late eighteenth century, rival proponents of phlogiston and oxygen battled it out to account for combustion, the controversy was illuminating. But it was decisively settled, and within a decade phlogiston was dead. So too with race, gender and IQ. We had the debates some 30 years ago and, as Ceci and Williams agree, those who argued for genetic explanations for group differences (phlogiston theorists) lost. So why reignite a dead debate, unless it is to serve some sociopolitical, not scientific, end?

Ceci and Williams list some of those who have continued to insist that the issue is not closed, and defend them against the criticisms, and in some cases hostility, they have generated. To make their point, they invoke the spectre of Trofim Lysenko. The comparison is illuminating. Lysenko falsified experimental data in defence of politically expedient but mistaken theories, with damaging effects on Soviet agriculture. When in the 1940s his theories received Joseph Stalin's imprimatur, Soviet genetics, which had flourished through the 1920s and 1930s, was destroyed. But they have their comparison the wrong way round. In the present case it is the proponents of race–gender–IQ theories who are defending a mistaken but politically expedient theory, with potentially seriously damaging social consequences.

Ceci and Williams defend the principle of free speech; you should not be silenced for arguing for phlogiston, although your grant applications based on the theory are unlikely to be funded (except by Foundations for the Defence of Phlogiston, which certainly exist in the case of race, gender and IQ). But it is my impression that, far from being silenced, phlogiston theorists get quite a bit of time on air and in print. Freedom of speech should be defended, but it cannot be an unbounded freedom in cases where, more than just falsely crying “Fire!” in a crowded theatre, the speech provides the matches and petrol for those who are actively trying to set the place alight.

See also: The belief that genes cannot be changed is now outdated Identifying adaptive differences could provide insight The arrogance of trying to sum up abilities in a number Is poverty better explained by history of colonialism? Would you wish the research undone? Measured intelligence is a product of social processes A useful way to glean social information