There Are Innate Gender Differences in Abilities, But It Probably Won't Be So Controversial This Time

The Chronicle of Higher Education summarizes some papers presented at the AEA meetings in Atlanta over the weekend, including "Explaining The Worldwide Boom in Higher Education of Women," by Gary Becker, William Hubbard and Kevin Murphy (University of Chicago). The authors show that in 67 of 120 countries more women than men hold college degrees. And the degree gap is not restricted to high-income countries: The 67 countries include 17 where per-capita income is below the global median. For the U.S., about 36% of women aged 30-34 years have college degrees, compared to only 28% of men.

The authors argue that the economic and noneconomic benefits of completing college have been increasing, and that those benefits are still generally larger for men than for women. So why haven't men been flooding into college at the same rates as women? One central answer, according to the authors, is that women generally have stronger "noncognitive skills"—that is, self-discipline and focus—than do men, and that they are therefore more likely to complete college.

From the paper:

Gender differences in the distributions of cognitive and non-cognitive abilities might be important in explaining gender differences in the propensities to go to and graduate from college. Gender differences in the means of cognitive measures like IQ are minor, but the degree of variability in cognitive abilities appear to be greater among men than women.

However, the main ability differences between men and women are in the non-cognitive arena. Non-cognitive abilities affect grades and test scores by affecting how much attention students pay to instruction from their teachers, how organized they are in doing homework and preparing for exams, whether they get disciplined for inappropriate behavior at school, and in various other ways.

Table 2a and 2b above present several measures of the mean and variability in the non-cognitive abilities of boys and girls. They show that girls have both higher average levels and smaller variances of non-cognitive abilities than boys do. Importantly, non-cognitive abilities are at least as important as cognitive abilities in determining academic success and life outcomes. Heckman, Stixrud, and Urzua (2006) find that non-cognitive skills are as important as, if not more important than, cognitive skills in determining many aspects of social and economic success including the probability of being a 4-year-college graduate at age 30.

MP: What's interesting and troubling at the same time is that these results showing significant gender differences in non-cognitive abilities will probably be accepted (embraced?) as completely non-controversial, for one main reason: the gender differences for non-cognitive abilities show that women are superior to men, and suggest that there are innate gender differences favoring women that explain why they outnumber men in higher education.

Contrast that to the reception Larry Summers got when he suggested that innate differences in the variability of male and female cognitive abilities might be one reason fewer women succeed in science and math careers. And if you look at Figure 19 in the Becker et al. paper, you'll find empirical support for what Summers said - there is significantly greater variability of male test scores vs. female test scores, and that finding is consistent across almost all countries and all four tests (math, reading, science and problem solving).