That there has been an abundance of bad science used to argue for female difference (and typically, inferiority) is amply illustrated by Fine’s use of century-old statements by eminent scientists of their day, bemoaning the smaller brain size of women, or their doomed-to-fail efforts to reach political equality with men. They are hilarious, of course, but depressing as well — and even more so when compared with contemporary arguments about Mars and Venus. Today’s neurosexism, as Fine tags it, may one day meet the same fate as yesterday’s scientific explanations for sexism, racism, and other forms of bigotry, the vividly colored brain scans showing feminine multitasking or masculine focus joining the calipers that once measured facial verticality and the cephalic index in the dustbin of scientific history.

Fine is at her most effective when skewering those who make hay of alleged brain-based differences between men and women. After quoting an advocate of single-sex education, she addresses the reader directly, noting that “[b]y now, you will probably be uneasy about the idea that complex psychological skills like language, math, and geometry can be pinpointed to a single part of the brain.” And she’s right: Whether or not you believed in hard-wired gender differences before reading her book, it would be difficult to complete it without feeling at least a healthy skepticism about the role of biology in the way our lives play out. Fine wants you to think more deeply about whether women enter science and math less frequently than men for reasons of brain wiring or because their lived experience (and hundreds of magazines articles) have told them they’d be unhappy there. She’d like you to wonder whether women truly step off the career treadmill more frequently than men because they care less about work than about family, or whether it’s because our society is still arranged in such a way that women — even those who earn more than double what their husbands make — put in nearly twice as many hours of domestic work a week. As she puts it, “So when a female academic . . . jumps off the academic ladder and into a more flexible but dead-end second-tier research position, is it because she’s intrinsically less interested in a demanding academic career or because there are only twenty-four hours in a day?”