We also know that the differences within each sex are far larger than the average difference between the sexes. And we know that sex differences in math are smaller than cross-national differences. One study, comparing the United States, Taiwan and Japan, found that Japanese girls in grammar school scored almost twice as high on certain tests as American boys and almost always scored distinctly higher.
Maybe Asians are innately better at math. If so, following Summers's reasoning, Harvard should be preferentially hiring Asian women over American men. (We don't know what's behind the large cross-national differences -- although education is key -- and, as Americans, we're a little reluctant to think we're inferior.)
Playing to Stereotype|
One thing about stereotypes is how very good human beings prove to be at living up to them: Tell a woman that she is not up to some complex computation or an African American that he probably won't do as well as white students on a difficult standardized test and -- bingo! -- she or he may well fulfill those expectations.
This theory, known as "stereotype threat," is defined by psychologist Claude M. Steele of Stanford University as "the threat of being viewed through the lens of a negative stereotype." The anxiety it produces, Steele asserts, is a significant factor in the continuing underperformance of groups whose abilities are stigmatized, such as women in the sciences and black college students.
Steele and his colleagues, Joshua Aronson of New York University and Steven Spencer of the University of Waterloo, alerted black and white students that a challenging verbal quiz would measure their abilities. The black students then performed measurably worse than the whites, even though the students selected were statistically equivalent in ability level.
But when the researchers told the students that the quiz was a lab task that did not measure ability -- thus making the stereotype about ability irrelevant -- the blacks' performance matched the whites'.
Similarly, women underperformed when told in advance of taking a math test that men generally scored better on it. Take the stereotype threat away, however, and the performance of these underachievers also goes up.
That's why, says Steele, "reinforcing a stereotype with no good reason is irresponsible." Simply by voicing the possibility that women are less able in science than men, Harvard President Lawrence H. Summers may be helping to bring about that outcome.
-- Frances Stead Sellers, Outlook
By the Numbers|
Percentage of women holding tenured and tenure-track faculty positions at the "top 50" university departments of:
Chemical engineering: 10.5%
Mechanical engineering: 6.7%
Electrical engineering: 6.5%
Civil engineering: 9.8%
Computer science: 10.6%
SOURCE: Donna Nelson, associate professor of chemistry, University of Oklahoma
In the meantime, we don't cultivate women who are strong in math. A study of seventh- and eighth-graders in the top 1 percent of math performers shows that the girls do not improve their scores over a four-year period to the same extent that boys do; nor do girls in that top pool continue in math and science at the same rate as boys. We cultivate and nurture mathematically inclined boys. And children -- like adults -- have a tendency to fulfill expectations. We expect boys to excel at math and treat them accordingly. Shouldn't we do the same for girls?
There is one cognitive ability that appears to be linked to sex differences in hormones. It's called mental rotation: the ability to look at a picture of a three-dimensional block figure and imagine it rotated in space. Males are much better than females at this task (although, with practice, someone of either sex can improve), and that result appears to be related to testosterone level. Girls who have experienced excess androgen in utero show higher mental rotation scores than normal girls. That's the kind of evidence we need to demonstrate a hormonal connection. We don't have that evidence for math or other cognitive differences. Does mental rotation ability matter? Maybe for a couple of scientific fields, but on balance, differences in math abilities seem better accounted for by differences in what we expect of women and how we treat them.
The National Science Foundation has recognized that the nation loses out if colleges and universities squander the talents of women faculty members. And if women are going to thrive in math and science, academia has to change. To speed that change, the NSF has awarded ADVANCE Institutional Transformation Awards to 19 schools, of which Hunter College, where I teach, is one. And there are already results from this ambitious new program: These schools are hiring more women, improving their promotion and tenure policies, and doing more to ensure that women have the resources to do their best work.
Summers now says he was wrong to have spoken in a way that has sent an unintended signal of discouragement to talented women. He also has pledged $25 million to promote the hiring of women and minorities at Harvard.
That message would have been a welcome addition to his comments at the Jan. 14 conference. The most important message, though, is that if we raise expectations of women in science -- and give them the resources they need -- they will make it to the top.
Virginia Valian is a professor of psychology and linguistics at Hunter College and the CUNY Graduate Center in New York and the author of "Why So Slow? The Advancement of Women" (M.I.T. Press).