The House of Representatives has passed what I like to think of as Larry’s Law. The official title of this legislation is “Fulfilling the potential of women in academic science and engineering,” but nothing did more to empower its advocates than the controversy over a speech by Lawrence H. Summers when he was president of Harvard.
This proposed law, if passed by the Senate, would require the White House science adviser to oversee regular “workshops to enhance gender equity.” At the workshops, to be attended by researchers who receive federal money and by the heads of science and engineering departments at universities, participants would be given before-and-after “attitudinal surveys” and would take part in “interactive discussions or other activities that increase the awareness of the existence of gender bias.”
I’m all in favor of women fulfilling their potential in science, but I feel compelled, at the risk of being shipped off to one of these workshops, to ask a couple of questions:
- Would it be safe during the “interactive discussions” for someone to mention the new evidence supporting Dr. Summers’s controversial hypothesis about differences in the sexes’ aptitude for math and science?
- How could these workshops reconcile the “existence of gender bias” with careful studies that show that female scientists fare as well as, if not better than, their male counterparts in receiving academic promotions and research grants?
Each of these questions is complicated enough to warrant a column, so I’ll take them one at a time, starting this week with the issue of sex differences.
When Dr. Summers raised the issue to fellow economists and other researchers at a conference in 2005, his hypothesis was caricatured in the press as a revival of the old notion that “girls can’t do math.” But Dr. Summers said no such thing. He acknowledged that there were many talented female scientists and discussed ways to eliminate the social barriers they faced.
Yet even if all these social factors were eliminated, he hypothesized, the science faculty composition at an elite school like Harvard might still be skewed by a biological factor: the greater variability observed among men in intelligence test scores and various traits. Men and women might, on average, have equal mathematical ability, but there could still be disproportionately more men with very low or very high scores.
These extremes often don’t matter much because relatively few people are involved, leaving the bulk of men and women clustered around the middle. But a tenured physicist at a leading university, Dr. Summers suggested, might well need skills and traits found in only one person in 10,000: the top 0.01 percent of the population, a tiny group that would presumably include more men because it’s at the extreme right tail of the distribution curve.
“I would like nothing better than to be proved wrong,” Dr. Summers told the economists, expressing the hope that gender imbalances could be rectified simply by eliminating social barriers. But he added, “My guess is that there are some very deep forces here that are going to be with us for a long time.”
Dr. Summers was pilloried for even suggesting the idea, and the critics took up his challenge to refute the hypothesis. Some have claimed he was proved wrong by recent reports of girls closing the gender gap on math scores in the United States and other countries. But even if those reports (which have been disputed) are accurate, they involve closing the gap only for average math scores — not for the extreme scores that Dr. Summers was discussing.
Some scientists and advocates for gender equity have argued that the remaining gender gap in extreme scores is rapidly shrinking and will disappear. It was called “largely an artifact of changeable sociocultural factors” last year by two researchers at the University of Wisconsin, Janet S. Hyde and Janet E. Mertz. They noted evidence of the gap narrowing and concluded, “Thus, there is every reason to believe that it will continue to narrow in the future.”
But some of the evidence for the disappearing gender gap involved standardized tests that aren’t sufficiently difficult to make fine distinctions among the brighter students. These tests, like the annual ones required in American public schools, are limited by what’s called the ceiling effect: If you’re measuring people in a room with a six-foot ceiling, you can’t distinguish among the ones taller than six feet.
Now a team of psychologists at Duke University has looked at the results of tests with more headroom. In an article in a forthcoming issue of the journal Intelligence, they analyze the test scores of students in the United States who took college admissions tests while they were still in the seventh grade. As part of an annual talent search since 1981, the SAT and ACT tests have been given to more than 1.6 million gifted seventh graders, with roughly equal numbers of boys and girls participating.
The Duke researchers — Jonathan Wai, Megan Cacchio, Martha Putallaz and Matthew C. Makel — focused on the extreme right tail of the distribution curve: people ranking in the top 0.01 percent of the general population, which for a seventh grader means scoring above 700 on the SAT math test. In the early 1980s, there were 13 boys for every girl in that group, but by 1991 the gender gap had narrowed to four to one, presumably because of sociocultural factors like encouragement and instruction in math offered to girls.
Since then, however, the math gender gap hasn’t narrowed, despite the continuing programs to encourage girls. The Duke researchers report that there are still four boys for every girl at the extreme right tail of the scores for the SAT math test. The boy-girl ratio has also remained fairly constant, at about three to one, at the right tail of the ACT tests of both math and science reasoning. Among the 19 students who got a perfect score on the ACT science test in the past two decades, 18 were boys.
Meanwhile, the seventh-grade girls outnumbered the boys at the right tail of tests measuring verbal reasoning and writing ability. The Duke researchers report in Intelligence, “Our data clearly show that there are sex differences in cognitive abilities in the extreme right tail, with some favoring males and some favoring females.”
The researchers say it’s impossible to predict how long these math and science gender gaps will last. But given the gaps’ stability for two decades, the researchers conclude, “Thus, sex differences in abilities in the extreme right tail should not be dismissed as no longer part of the explanation for the dearth of women in math-intensive fields of science.”
Other studies have shown that these differences in extreme test scores correlate with later achievements in science and academia. Even when you consider only members of an elite group like the top percentile of the seventh graders on the SAT math test, someone at the 99.9 level is more likely than someone at the 99.1 level to get a doctorate in science or to win tenure at a top university.
Of course, a high score on a test is hardly the only factor important for a successful career in science, and no one claims that the right-tail disparity is the sole reason for the relatively low number of female professors in math-oriented sciences. There are other potentially more important explanations, both biological and cultural, including possible social bias against women.
But before we accept Congress’s proclamation of bias, before we start re-educating scientists at workshops, it’s worth taking a hard look at the evidence of bias against female scientists. That will be the subject of another column.