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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 technology, researchers can get a good look at the living brain as it functions and grows. Earlier studies relied on autopsies or X rays--and no one wanted to expose children or women, who might be pregnant, to regular doses of radiation.