He Thinks, She Thinks
The male and female brains explained

Tim Johnson

Men and women are different — that much needs hardly be said. But in the past few years, new technology has allowed us to peek inside the physical brain and learn a lot about what makes the sexes different. “When you look a little deeper into the brain differences, they reveal what makes women women and men men,” writes Dr. Louann Brizendine, a neuropsychiatrist at the University of California at San Francisco, in her bestselling book, The Female Brain. So, the next time you wonder why he can’t seem to grasp what you’re feeling, or she can’t comprehend why you just did that, recall the examples listed below.

Illustration by Sandy Nichols/ThreeInABox.com

Aggression

On the whole, women tend to be less physically aggressive than men, a trait that may be related to the amygdala, an almond-shaped structure in the brain that helps us feel and perceive emotion. It is also a key player in the fight-or-flight stress response. A woman’s amygdala is smaller than a man’s and also closer in size to her orbitofrontal cortex, the braking region that inhibits us from expressing emotions generated in the amygdala. “This may relate to the lower frequency of physical aggression in women,” says Dr. Ruben Gur, director of the Brain Behavior Laboratory at the University of Pennsylvania in Philadelphia. Or, as Brizendine puts it, “This is why some men can go from zero to a fist fight in a matter of seconds, while many women will try anything to defuse a conflict.”

Sex

In men, the brain centres related to sex (such as the hypothalamus) are about twice the size of those in women. In general, men think about sex much more than women. Brizendine notes that while sexual thoughts float through a man’s brain many times on an average day, they surface in a woman’s only once. “On her ‘hottest’ day, a woman may think about sex three or four times,” she says. So now you know the basis of her perennial question “Is that all you ever think about?”

Emotive recall

On the other hand, a woman’s hippocampus, the cerebral region that serves as a terminus for emotion and the formation and storage of memory, is larger. And the links between the emotion centres of the brain are also more active in women. A U.S. study found that in activating the amygdala (which helps to translate emotional events into memory), women favour the left side and men the right. “This may produce, on average, a disproportionate boost in memory for the details of an emotional situation for women versus the gist of an emotional situation in men,” says lead investigator Dr. Larry Cahill, a neuroscientist at the University of California at Irvine.

Navigation

A woman has a larger hippocampus, but this may be a disadvantage when it comes to navigating, as the male of the species generally tends to have better navigational skills. In addition to its importance for memory, the hippocampus is also involved in the spatial mapping of our physical environment. Studies have consistently shown that women tend to navigate by using landmarks, while men are more likely to estimate distance in space and orientation. A similar trend has been observed in rat studies. But, as Cahill notes, “investigators have yet to demonstrate that male rats are less likely to ask for directions.”

Talking

In the brain’s limbic system — which is known as the “emotional brain” — women have higher rates of metabolism in the cingulate gyrus, a long curved structure that sits next door to the language area. This may explain, says Gur, why women tend to be better at talking about their emotions. And, he adds, “If you ask subjects to relax and think about whatever they like, in men you find that the part of the limbic system below the corpus callosum — the more primitive part — becomes active, so they may fantasize about aggression or sex or competitive sports. In women, the more active part is the one that appeared later in evolution and is adjacent to language areas, so they may be more likely to think in words.” Now you know why he never wants to talk about his feelings.

Multi-tasking

Men tend to use either their right or their left brain when approaching a task, while women often use both sides. “Women’s brains tend to be more bilaterally organized and tend to have a thicker, more massive corpus callosum, the superhighway that runs between the brain’s two hemispheres,” says Cahill. Some researchers hypothesize that this is why women tend to be better at multi-tasking than men. It might also mean that a woman will look at a situation from a number of different angles and include both the logical and the emotional in her assessment, says Gur. Men’s brains, on the other hand, have more white matter, which contains fibres from inhibitory neurons that foster local processing. This may explain how men can focus on a single task and — maddeningly — tune out surrounding distractions. Perhaps that’s why he can zero in on a laptop while the phone’s ringing, the baby’s screaming and the supper’s burning, and can’t comb his hair and carry on a conversation at the same time.

Other researchers point out that structural differences in the brain probably account for women’s greater sensitivity to loud noises and odours. That’s why she cringes when he blasts the car radio or turns up the TV to ear-splitting levels and doesn’t understand why he can’t smell that piece of broccoli liquefying at the back of the vegetable crisper.

For more on this topic, see The Essential Difference: Men, Women and the Extreme Male Brain (Penguin Press Science), by Simon Baron-Cohen.