Consider two recent high-profile cases. In 2005, Harvard’s then-president Lawrence Summers suggested gender differences in intrinsic ability as one cause of the dearth of women in the top tier of science, rather than espousing the popular view that women’s under-representation results from biased hiring, discriminatory tenure practices and negative stereotypes. Summers’s insinuation of biologically-based sex differences in cognitive ability was radioactive, setting off debates on campuses and outpourings of editorials. Despite apologizing for reckless language — which his supporters felt research supported — he later resigned.

James Watson is the most illustrious scholar to have his career ended for reckless language. Watson’s downfall was his assertion that “all our social policies are based on the fact that [African] intelligence is the same as ours — whereas all the testing says not really”. Although he hoped everybody was equal, “people who have to deal with black employees find this is not true”. Watson instantly plunged from A-list Nobelist to outcast, and was suspended from his chancellorship of Cold Spring Harbor Laboratory. Watson later clarified in a statement that he does not believe Africans to be genetically inferior, but this had little impact on the controversy.

Watson’s first assertion could be read as scientifically supported: black Africans’ IQ scores are lower than those of white Europeans. But Watson’s use of ‘intelligence’ was interpreted as meaning ‘intrinsic cognitive ability’, ignoring how unfamiliarity with testing format, low quality of schooling, or poor health might depress IQ scores. There have been analyses showing average national IQs for sub-Saharan Africa to be approximately 30 points lower than average IQs for predominantly white European nations, and drawing a racial conclusion from those results. A refutation of these analyses would provide an opportunity to advance understanding. Sadly, although these analyses can be refuted, as we and others have done, most of those who scorned Watson never knew they existed.

Attacks on Watson and Summers extinguished discussion by making moral attributions about their presumed character flaws rather than debating facts. But character attacks lead to a one-party science that squelches divergent views.

Some scientists hold more ‘acceptable’ views, ourselves included. We think racial and gender differences in IQ are not innate but instead reflect environmental challenges. Although we endorse this view, plenty of scholars remain unpersuaded. Whereas our ‘politically correct’ work garners us praise, speaking invitations and book contracts, challengers are demeaned, ostracized and occasionally threatened with tenure revocation.

Stephen Ceci and Wendy M. Williams, ‘Should scientists study race and IQ? YES: The scientific truth must be pursued’, Nature, vol. 457, no. 7231 (February 12, 2009), pp. 788-789