This fits rather well with what we know about stereotype threat. Under-representation tends to be self-perpetuating, and this specific mechanism is a powerful one, of which philosophers should take note. (The start of the article is, I think, irritating, But it’s worth persevering.)
The psychologists asked female students studying biology, chemistry, and engineering to take a very tough math test. All the students were greeted by a senior math major who wore a T-shirt displaying Einstein’s E=mc2 equation. For some volunteers, the math major was male. For others, the math major was female. This tiny tweak made a difference: Women attempted more questions on the tough math test when they were greeted by a female math major rather than a male math major. On psychological tests that measured their unconscious attitudes toward math, the female students showed a stronger self-identification with math when the math major who had greeted them was female. When they were greeted by the male math major, women had significantly higher negative attitudes toward math.
In a more ambitious experiment organized with the university’s math department, the psychologists evaluated how undergraduates performed when they had male or female math professors.
They measured, for instance, how often each student responded to questions posed by professors to the classroom as a whole. At the start of the semester, 11 percent of the female students attempted to answer questions posed to the entire class when the professor was male, and 7 percent of the female students attempted to answer questions posed to the entire class when the professor was female. By the end of the semester, the number of female students who attempted to answer questions posed by a male professor had not changed significantly: Only 7 percent of the women tried to answer such questions. But when classes were taught by a woman, the percentage of female students who attempted to answer questions by the semester’s end rose to 46.
The researchers also measured how often students approached professors for help after class. Around 12 percent of the female students approached both male and female professors for help at the start of the semester. The number of female students approaching female professors was 14 percent at the end of the semester. But the number of female students asking for help from a male professor dropped to zero.
Finally, when Stout and Dasgupta evaluated how much the students identified with mathematics, they found that women ended up with less confidence in their mathematical abilities when their teachers were men rather than women. This happened even when women outperformed men on actual tests of math performance.