Why do boys outperform girls in math, especially at the highest levels of math achievement? Two sets of economists released papers this summer examining the size of the gender gap in math achievement and investigating some possible contributing factors.
The first paper, released in July 2009 by Roland Fryer and Steven Levitt, found that while there are no mean differences between boys and girls in math when they start school, girls gradually lose ground, so that the gap between boys and girls after six years of schooling is half as large as the black-white test score gap. The researchers attempted to find an explanation for the gender gap. They write “We explore a wide range of possible explanations in the U.S. data, including less investment by girls in math, low parental expectations, and biased tests, but find little support for any of these theories.” One interesting thing they did find was that girls do not lag behind boys in countries with same-sex schooling at the secondary school level, such as Bahrain, though they did not investigate whether the relationship is causal. (Over at one of the New Republic’s blogs, Zubin Jelveh asked “Is Islam Good for Girls’ Math Scores?”)
The second study, released by Glenn Ellison and Ashley Swanson (also in July 2009), examined the results of high school mathematics competitions and found that the gender gap widens dramatically at the highest levels of math performance. They also found that the top female math students are concentrated in a very small set of super-elite schools (e.g. Phillips Exeter Academy). As Kevin Lewis wrote in the Boston Globe, “Unless the parents of all the gifted girls in the country are enrolling their kids in the same schools, the evidence suggests that a lot of female talent is just not being tapped.” Ellison and Swanson note in their paper that their focus is on reporting the facts rather than on attempting to explain the factors that may contribute to the gender gap. However, they write,
If asked to speculate, our first remark would be that several elements in our results seem consistent with the view that girls suffer because they are more compliant with authority figures and/or are more sensitive to peer pressure. Most high schools offer math courses to suit students at several different levels. But, even in the highest-level “honors” courses, it is probably unusual to teach material at the level needed to bring students to the 99th percentile. If girls are less likely to complain and get schools to make special accomodations, then we would expect them to be more underrepresented among students with skill levels that are farther beyond those developed in the classroom. Peer pressure would also presumably be more limiting when we look at achievement levels that are only likely to be reached if students join a math team or take online courses.