Women who read of genetic causes of sex differences performed worse on math tests than those who read of experiential causes.

So concluded researchers Ilan Dar-Nimrod and Steven J. Heine in Exposure to Scientific Theories Affects Women's Math Performance (link behind a paywall) in Science Magazine October 20, 2006.

Now, for those of us who have been following the research related to the idea of "stereotype threat" (when stereotyped groups perform worse as their group membership is highlighted), a concept originally identified by Claude Steele at Stanford, this won't particularly be news, but it remains interesting.

Dar-Nimrod and Heine, researchers at the University of British Columbia, testing 135 women on a challenging series of mathematics question found:

The women told prior experience determined their math ability got twice as many answers right on the exam as women told their genetics were to blame.

Given what we know about stereotype threat, and what we know about the degree to which even intelligent and well-read people in upper levels of demanding fields assume with regards to gendered abilities and expectations in mathematics (see our favorite president of Harvard, for example), I can't help wondering if any woman in a rigorous field of science or mathematics isn't constantly working under the shadow of stereotype threat.

You can also read about the study in the Globe and Mail:
Stereotypes add up on math tests.