Men Fall in Love Faster Than Women

Digested from NYTimes -- The little blue pill, though able to stir arousal, did not always evoke sexual desire in women.

Viagra's failure underscored the obvious: when it comes to sexuality, men and women to some extent are differently tuned. For men, arousal and desire are often intertwined, while for women, the two are frequently distinct.

Scientists have recently begun to map out how this difference shows up in the brain.

For example, male arousal, studies find, is strongly visual, and when men engage in sexual activity or even anticipate it, brain structures once thought to have little connection to sex spring into action. The same brain regions, however, remain relatively quiet when women are aroused.

Some experts argue that, over time, men naturally became more dependent than women on sight in selecting a mate.

"For millions of years, men have had to size up a woman's reproductive capacity by looking for signs of youth and health that would enable them to carry a healthy baby," said Dr. Helen Fisher, an anthropologist at the Center for Human Evolutionary Studies at Rutgers, and the author of a recently published book, "Why We Love: The Nature and Chemistry of Romantic Love."

Dr. Fisher has studied the brains of people in the early stages of romance. For a man, she found, pictures of a new partner light up parts of the brain involved in visual processing and arousal. But women, she noticed, show more activity in areas linked to reward, emotion and attention.

"Men, despite what most people think, fall in love faster than women do, probably because they're so visual," Dr. Fisher said.

Women, on the other hand, may be more attuned to the signs that a man will make a good father or provider, she added, though some other researchers find this assertion dubious. A woman's choice of a mate, Dr. Fisher argues, could involve an interplay among a number of factors, including, some experts now theorize, a man's odor.

Several years ago, Swiss scientists discovered that women could sniff out genetic differences in potential mates. When women were asked to smell T-shirts that different men had worn, they often ranked more favorably the shirts that belonged to men with dissimilar genes for major histocompatibility complex, a group of proteins involved in immunity to disease. The odors a woman preferred also tended to remind her of past and current partners.

Seeking out different immune-system genes might be a way to prevent inbreeding or to arm offspring with a more versatile immune system, said Dr. Rachel S. Herz, a psychologist at Brown who in a study in 2002 found that women ranked body odor above almost every other factor in attraction, except "pleasantness."

In research last year at Northwestern, Dr. Meredith Chivers, demonstrated that women could sometimes have more powerful responses to visual stimuli than men, although in different ways.

In her study, which ignited a small firestorm, Dr. Chivers used a device to measure genital arousal in subjects as they looked at pornography. Heterosexual men, she found, were aroused by footage of men and women having sex. Gay men reacted to two men having sex. Women, regardless of sexual orientation, responded to everything.

In some cases, she said, women reported no sexual arousal, though the device said otherwise.

People's perceptions are colored by their personal experiences, said Dr. Leonore Tiefer, a sex therapist who is a clinical associate professor of psychiatry at the New York University medical school.

"Differences between genders are boring," Dr. Tiefer said. "The big differences are within the sexes, between individuals. It is not the case that every person pays attention to the same thing.

"It's like everything else in life — eating, dancing, traveling. The whole experience is shaped by your history and by what you're paying attention to."

el - I have given up on ever understanding women but still keep studying.