HOW GENDER MAY BEND YOUR THINKING

By Christine Gorman

Why can't a woman think more like a man? That's the sort of question one would expect to hear from an unrepentant chauvinist like Shaw's Professor Higgins. But a growing number of scientists have begun wondering the same thing. Relying in part on advanced brain-scanning techniques, they have amassed tantalizing hints that men and women may use their heads in subtly distinctive ways.

Just last week a new study showed that in science tests teenage boys who scored in the top 5% outnumbered girls 7 to 1, while girls outperformed boys in reading comprehension. In general, men as a group excel at tasks that involve orienting objects in space-like reading a map without having to turn it so it lines up with the road. Women, on the other hand, seem to be more adept at communication, both verbal and nonverbal. Readings of mri scans suggest one reason: women seem to have stronger connections between the two halves (hemispheres) of their brain.

What's sauce for the goose need not be a problem for the gander, however. The relative lack of cross talk between their hemispheres may actually benefit men by allowing each half of the brain to concentrate on what it does best. Studies have shown that when men are confronted with problems that deal with spatial orientation -- a function that can be handled by both the left and right hemispheres -- they tend to use the right hemisphere only. Thus there aren't many distracting messages coming in from the left hemisphere, which concentrates on language. This cerebral division of labor could also explain why there are so many more male architects and chess champions. Their brains may simply be better able to concentrate on solving problems involving spatial relations.

Just because scientists can measure these differences, however, does not mean they understand their causes. Are men born with better spatial abilities, or do they develop them by playing sports in which eye-hand coordination is crucial? Are women innately better at reading words and understanding emotions, or do they just get more practice? If heredity and biology are important, though, then it's a pretty good bet that the sex hormones are somehow involved. For that reason, researchers have begun delving into the effects of testosterone and estrogen on the brain.

Although romantics of all ages can recall occasions when lust interfered with reason, scientists once believed sex hormones had very little effect on the brain. The chemicals' only target was supposed to be a tiny structure called the hypothalamus, buried deep in the brain, which is the seat for sexual drive and other urges, such as appetite and aggression. Recent research, however, has shown that the entire brain, including the thought-processing cortex, is awash in sex hormones, even before birth. The larger amounts of testosterone produced by males may predispose men's brains toward greater specialization of the two hemispheres.

This oversimplifies the case, of course. There are men whose brains are not especially compartmentalized, and women whose brains are. And even when a brain fits the mold, performance is not always predictable. Consider Judit Polgar, who at 15 became the world's youngest chess grand master. Her success does not mean she has a male-wired brain. Nor did Shakespeare, whose intuitions about women were uncanny, necessarily have female wiring. The variation between the sexes pales in comparison with individual differences-and shows how marvelously versatile a 3-lb. mass of nerve cells can be.