Gender Gap Remains Chasm of Intrigue : Sexuality: Boys and girls may be born with slightly different potentials, psychologists say, but it’s what people do with their ability that’s important.

Why can’t a woman be more like a man?” Prof. Henry Higgins woefully warbled in puzzlement over his fair lady.

If she were, she would be more aggressive, less communicative and die earlier. And surely even the irascible professor was not calling for that kind of equality of the sexes.

Beyond the obvious differences--and vive la difference many would agree with the French--the unique qualities that characterize each of the sexes have long fascinated everyone from poets to scientists, from women who wonder why men do not share their feelings to men who grumble about women drivers.

Gender differences in such areas as skills, temperament and life span have been documented but in many cases disputed. What is inborn and what is learned? How much is biological and how much is societal?

“This is the whole story of nature vs. nurture,” says Dr. Claude Migeon, who heads the pediatric endocrinology clinic at Baltimore’s Johns Hopkins Hospital. “You cannot always tease out one from the other.”

While endlessly fascinating, gender differences also have proven troublesome. Feminists, for example, naturally are leery of the biology-is-destiny implications that in the past have prevented women from pursuing “men’s” work. And others have argued that the focus should not be on what boys and girls are born with, but on how their upbringing may lead them to fall into the stereotypical male or female roles.

“What people do with their ability is what’s important,” says Camilla Benbow, an Iowa State University psychologist and researcher in gender differences. “Maybe boys and girls come out with slightly different potentials, but how that potential is expressed is due to their environment.”

What follows is a look at what is known--and what is not known--about the gender gap, from the moment of conception to death.

In the Womb

The genetic die is cast at conception, but it takes a couple of months before the net result becomes apparent.

At fertilization, the sperm carries either an X or a Y chromosome, which determines whether the fetus will be female (X) or male (Y). Until the eighth to 10th week of gestation, however, the fetus looks female, says Migeon.

In a reverse of the Biblical creation of Adam first and Eve second from one of his ribs, males really spring from females, in the genetic sense.

“A man is really a female with testosterone,” Migeon says.

At eight to 10 weeks, gender differentiation begins as the fetus develops either male or female sex organs.

If the fetus inherited a Y chromosome, it will begin producing testosterone, the male hormone that, later in life, is responsible for the physical--and some believe emotional--characteristics of males, such as larger skeletons, facial and body hair.

Babies and toddlers are, of course, much more complicated than fetuses, and more susceptible to expectations from parents and others. So it gets trickier to identify genetic differences, and say where they come from--biology or environment.

But, experts say, the differences are there.

“Somewhere around 11 to 12 months, when the mother leaves the room, or puts the baby to bed, the girl baby becomes kind of withdrawn into herself; she seems sad,” says Dr. Taghi Modarressi, a psychiatrist at the University of Maryland. “But the boy baby becomes hyperactive, thrashing around.”

At 17 to 18 months, another difference becomes apparent: Girls begin exhibiting a greater facility with language.

“Most girls by that age are able to put two words together,” says Modarressi, while boys develop that skill a couple of months later. He says girls also develop other language skills, such as accumulating a vocabulary and making complete sentences, earlier than boys.

Spatial Skills

Boys, by contrast, develop a better perception of space, he says.

“If you leave children in an ambiguous situation, with ambiguous markers on directions,” says Modarressi, “the chances for a boy to find the direction out is better, as early as 2 or 2 1/2 years of age.”

Still, he adds, with the variability of infants and their environments, it is hard to pin down the differences or locate their origins.

“Nobody can really swear by these things,” Modarressi says. “It’s so subtle; it’s hard to say. When we talk about inborn, intrinsic maleness and femaleness, we really don’t know what we’re talking about.”

The seemingly incessant testing that goes on in a child’s school life has produced a wealth of data for gender researchers. But interpretations of that data can prove controversial.

In the past, and in very general terms, males performed better than females on math tests while the reverse was true on verbal tests. But recent research indicates the gap has narrowed--although it has remained significant--in math scores and has virtually disappeared in verbal scores. The reasons for this are complex and still open to speculation.

Experts have pointed to biological and sociological factors that may come into play. Some believe, for example, that the brain is specialized, with the left brain responsible for language and the right brain responsible for nonverbal, or spatial, skills. Left-handedness, which is believed to correlate to right-brain domination, is more prevalent in males, leading to speculation that that may be why males generally do better in math and spatial skills tests.

But more attention has been focused on the different signals that parents and teachers send to boys and girls in educational matters, and how that might contribute to their different accomplishments.

“One of the hypotheses I’m interested in right now is the way women are socialized and their belief of how they’re going to use math in the future,” says Nancy Burton, program director for the Scholastic Aptitude Test. “They’re fine while they’re taking a course in it, but they haven’t organized their thinking to use it in problem solving, which is what the tests test. But I have no proof of this.”

“Boys and girls, even at very young ages, and who perform equally on math tests, have different attitudes toward math.

“As young as third grade, girls say they don’t think they’re going to use math in the future, while boys state that they will.”

While hormones are usually viewed in reference to adolescence, when they turn boys into men and girls into women, they have a lifelong effect.

The female hormone, estrogen, is believed to keep women alive, on the average, longer than men. For women, it forestalls the inevitable march toward death.

“Both women and men die in the end, but the process begins later in women,” says Dr. David Smith, a Northwestern University expert on longevity.

Besides allowing women to reproduce, estrogen has the added effect of stimulating the liver to produce more of the “good” cholesterol, the high-density lipoproteins, or HDLs. The male sex hormone testosterone, on the other hand, produces more of the “bad” cholesterol, the low-density lipoproteins, or LDL.

That is why, says Smith, men have more heart problems and thus die earlier.

The other reason for women’s greater life span is societal, he says. Men traditionally have engaged in more health- and life-threatening behavior than women.

“Men drink more, they smoke more, they participate in violent behavior more, they wear seat belts less, they go to the doctor less,” he says.