Who Says Women Cannot Be Einstein

Yes, men's and women's brains are different. But new research upends the old myths about who's good at what. A tour of the ever changing brain

THERE WAS SOMETHING SELF-DESTRUCTIVE ABOUT Harvard University President Larry Summers' speech on gender disparities in January. In his first sentence, he said his goal was "provocation" (rarely a wise strategy at a diversity conference). He called for "rigorous and careful" thinking to explain the gender gap among top-tier tenured science professors. But he described his pet theory with something less than prudence. The most likely explanations, he said, are that 1) women are just not so interested as men in making the sacrifices required by high-powered jobs, 2) men may have more "intrinsic aptitude" for high-level science and 3) women may be victims of old-fashioned discrimination. "In my own view, their importance probably ranks in exactly the order that I just described," he announced.

Cue the hysteria. The comments about aptitude in particular lingered, like food poisoning, long after the conference ended. For weeks, pundits and professors spouted outrage and praise, all of which added up to very little. Then came the tedious analysis of faculty-lounge politics at Harvard, as if anyone outside Cambridge really cared.

The rest of us were left with a nagging question: What is the latest science on the differences between men's and women's aptitudes, anyway? Is it true, even a little bit, that men are better equipped for scientific genius? Or is it ridiculous--even pernicious--to ask such a question in the year 2005?

It's always perilous to use science to resolve festering public debates. Everyone sees something different--like 100 people finding shapes in clouds. By the time they make up their minds, the clouds have drifted beyond the horizon. But scientists who have spent their lives studying sex differences in the brain (some of whom defend Summers and some of whom dismiss him as an ignoramus) generally concede that he was not entirely wrong. Thanks to new brain-imaging technology, we know there are indeed real differences between the male and the female brain, more differences than we would have imagined a decade ago. "The brain is a sex organ," says Sandra Witelson, a neuroscientist who became famous in the 1990s for her study of Albert Einstein's brain. "In the last dozen years, there has been an exponential increase in the number of studies that have found differences in the brain. It's very exciting."

But that's just the beginning of the conversation. It turns out that many of those differences don't seem to change our behavior. Others do--in ways we might not expect. Some of the most dramatic differences are not just in our brains but also in our eyes, noses and ears--which feed information to our brains. Still, almost none of those differences are static. The brain is constantly changing in response to hormones, encouragement, practice, diet and drugs. Brain patterns fluctuate within the same person, in fact, depending on age and time of day. So while Summers was also right that more men than women make up the extreme high--and low--scorers in science and math tests, it's absurd to conclude that the difference is primarily because of biology--or environment. The two interact from the time of conception, which only makes life more interesting.

Any simplistic theory is "doomed to fail," says Yu Xie, a sociology professor at the University of Michigan. Xie's research on women in the sciences was cited by Summers in his statement, and Xie has spent every day since trying to explain the intricacy of human behavior to reporters. "I don't exclude biology as an explanation," he says. "But I know biological factors would not play a role unless they interacted with social conditions."

Unless one appreciates that complexity, it would be all too easy to look at the latest research on the brain and conclude, say, that men may not in fact make the best university presidents. For example, studies show that men are slightly more likely to say things without realizing how their actions will affect others. And as men age, they tend to lose more tissue from a part of the brain located just behind the forehead that concerns itself with consequences and self-control. Generally speaking, the brain of a female is more interlinked and--if one assumes that a basic requirement of the post is to avoid dividing the faculty into two sweaty mobs--may be better suited for the kind of cautious diplomacy required of a high-profile university leader. Of course, to borrow a line from Summers, "I would prefer to believe otherwise."

Now that scientists are finally starting to map the brain with some accuracy, the challenge is figuring out what to do with that knowledge. The possibilities for applying it to the classroom, workplace and doctor's office are tantalizing. "If something is genetic, it means it must be biological. If we can figure out the biology, then we should be able to tweak the biology," says Richard Haier, a psychology professor who studies intelligence at the University of California at Irvine.

Maybe Summers' failure was not one of sensitivity but one of imagination.

LESSON 1:

FUNCTION OVER FORM

SCIENTISTS HAVE BEEN LOOKING FOR SEX differences in the brain since they have been looking at the brain. Many bold decrees have been issued. In the 19th century, the corpus callosum, a bundle of nerve fibers that connects the two hemispheres of the brain, was considered key to intellectual development. Accordingly, it was said to have a greater surface area in men. Then, in the 1980s, we were told that no, it is larger in women--and that explains why the emotional right side of women's brains is more in touch with the analytical left side. Aha. That theory has since been discredited, and scientists remain at odds over who has the biggest and what it might mean. Stay tuned for more breaking news.

But most studies agree that men's brains are about 10% bigger than women's brains overall. Even when the comparison is adjusted for the fact that men are, on average, 8% taller than women, men's brains are still slightly bigger. But size does not predict intellectual performance, as was once thought. Men and women perform similarly on IQ tests. And most scientists still cannot tell male and female brains apart just by looking at them.

Recently, scientists have begun to move away from the obsession with size. Thanks to new brain-imaging