“How am I supposed to work?” I asked, staring dolefully at my husband. Our cat had been hit by a car the night before and was at the animal hospital, clinging to life. Even though I was on tight deadlines, I could think of nothing else.
“Just put it out of your mind,” he responded. “There’s nothing we can do.”
I almost strangled him.
My gal pals commiserate when I tell them this story later on because it seems as though we’d be incapable of that kind of detachment. Yet male friends look at me blankly, waiting for the punch line.
The fact is, men process their strong emotions differently from women and tend to act out and take action, which may explain why my husband—once he’d made sure our vet had the situation under control—was able to move on, while all I could do was obsess.
The contrasting ways men and women behave have provided plenty of fodder for Letterman and Leno. But beyond the Mars-Venus stereotypes, it’s not just the social conditioning we receive from the time we parachute down the birth canal that accounts for sex differences. Our brains are hardwired differently, and these anatomical variations in architecture and function illuminate some of the reasons why men and women seem to come from different planets.
Men and women, to be sure, “are more alike than they’re different, and even when there are variations, there is a significant overlap between the sexes,” says Nancy Andreasen, a psychiatrist and neuroimaging expert at the University of Iowa. But advances in such techniques as PET scans and functional MRIs (fMRIs) have enabled scientists to peer deep inside the brain and actually film it while a subject is thinking and processing information, giving them new insights into sex differences in storing memories, making decisions, and solving problems.
These findings offer tantalizing hints that even gender behavior differences once attributed solely to nurture—women are more emotionally attuned, while men are more physically aggressive—stem in part from variations in our neural circuitry.
“Neuroscience helps us to understand the underpinnings of behavior,” says Sandra Witelson, a neuroscientist at McMaster University in Hamilton, Ontario. “Sex differences in the brain in all likelihood translate into cognitive differences. And even when the differences are small, we don’t know how that plays out in daily life.”
The brain is divided into two hemispheres that play different roles in perception and behavior. The right side is relatively more involved with visual and spatial control, while the left is the seat of language. There is evidence that the male brain uses either one hemisphere or the other and relies on specialized brain regions when performing a task. Women, meanwhile, call on both hemispheres regardless of the task, resulting in greater communication between the two; they also enlist more brain regions to process information. When at rest, male minds appear to be more attuned to the “external world,” while there may be a “differential tilt toward the internal world” in female brains, says Larry Cahill, a neurobiologist at the University of California at Irvine.
Like many-handed Hindu goddesses, women are better jugglers (in my experience), sweeping through their lives performing several tasks at once, while men seemingly do things sequentially—a division of labor that certainly prevails in our household. Mornings find me feeding our animals, watching The Today Show, glancing at the newspaper, fixing coffee, sticking English muffins in the toaster, and emptying the dishwasher while my husband fries sausages. When they’re done, he whips up a fruit smoothie in the blender.
This distinct gender variation in the way we harness our brainpower may also illuminate why men are much more vulnerable to such developmental disorders as cerebral palsy, dyslexia, autism, and attention-deficit/hyperactivity disorder; in most cases, the increased incidence may be several times greater. Because women are less specialized, their brains seem to be more resilient—they recover faster and more easily from the effects of strokes—and better at compensating if one region is damaged.
Even when men and women do the same chores equally well, they may use different brain circuits to get the same result. In a 2005 Harvard University functional imaging study of working memory—that short-term memory we use to carry on conversations or remember telephone numbers—a group of volunteers were given verbal attention tasks while inside the scanning machine. This required that volunteers listen to prompts through a headset and respond accordingly.
While male and female participants performed about the same in terms of accuracy and reaction time, the neural pathways that were activated were different: Women showed greater activity in both hemispheres in the prefrontal cortex—in regions implicated in language functions and higher-level cognitive functions—than men. “We didn’t see sex differences in how well volunteers performed, but men and women used their brains differently to get the same results,” says Jill Goldstein, a professor of psychiatry and medicine at Brigham and Women’s Hospital and Harvard Medical School.
Men and women may take different routes, but they arrive at the same destination at about the same time. “It’s like two different automobiles,” says Witelson. “Each has a motor, a steering wheel, and brakes. But one is a Volvo and the other is a Lexus.”