[Y]ou can’t prove whether discrimination is going on in an organization—or a society—by statistics. You often read about “glass ceilings” for women in a given field or about disproportionate school suspensions of boys or minorities. The intimation—often the direct accusation—is that discrimination is at work. But numbers alone won’t tell the story. We don’t know that as many women as men have the qualifications or desire to be partners in law firms or high-level executives in corporations. And we have some pretty good reasons to believe that girls and boys are not equally likely to engage in behavior warranting suspension from school.

Not so long ago, it was common to attribute women’s lower representation in graduate school and faculty rosters to discrimination. And there certainly was discrimination. I know; I was there. I was privy to the conversations the men had about admitting women to grad school or hiring them onto faculties. “Go after the guy; women are too likely to drop out.” Bugged conversations would have proved what raw statistics, comparing percentage of men and women hired, could not.

But nowadays 60 percent of college graduates are women, and they constitute a majority of law and medical students as well as graduate students in the humanities, social sciences, and biological sciences. And the University of Michigan, where I teach, two-thirds of the assistant professors hired are women (and they get tenure at the same rate as men).

Do these statistics prove discrimination against men? They do not. And I can assure you that bugged conversations—at least at my school—would not support the discrimination idea either. On the contrary, we are so frequently confronted with the prospect of admitting huge majorities of women into our graduate program that we contemplate relaxing admission standards for men, though we’ve never carried it out in a conscious way, of that I’m sure.

The statistics on postgraduate education have not stopped some people from claiming there is still discrimination against women in the physical sciences. One book I read recently claimed that women were “locked out” of physics. In the absence of evidence other than the purely statistical kind, there can be no justification for that assertion.

Richard Nisbett, Mindware: Tools for Smart Thinking, New York: Farrar, Straus and Giroux, 2015, p. 188