My favorite finding of Dr. Brizendine's is her description of the different way the brains of girls and boys determine thinking about the opposite sex after puberty. The part of a boy's brain that controls sexual thought is twice the size of a girl's. Once his brain is flooded with testosterone, the boy is likely to think about sex every 52 seconds. Surges of estrogen may lead a teenage girl to obsess over her style and her need to look desirable, but that's as far as she wants to go. She buys, he lies.
"It's hard to believe that something as tiny as a little hormone could have such a robust behavioral effect for all of us," Dr. Brizendine tells ABC News' "20/20." Hormonal changes that occur in a woman after she gives birth reorient her behavior toward her husband. "The dad is there only in a supporting role now," she says. "Whereas he is used to being the main course, he's now like a side dish." (But maybe a sweet potato?)
We've long known that women are more verbal than men, but we've only recently established that the female emotional memory is longer. Women use 20,000 words in a day where a man is likely to use only 7,000 (and often says just as much). Add her long memory to his laconic reticence and you can understand how men and women argue differently. A man is nearly always at a disadvantage when a woman recalls every argument they've ever had. He doesn't remember any of them, or so he says.
But men and women change as they grow older. Baby boomers, now entering their 60s, still work out at the gym as a way to stay fit, but the latest trend for seniors may reflect changing hormones and diminished aggression. They're returning to ballroom dancing as an alternative to exercise. Dancing burns from 250 to 400 calories an hour. Membership in USA Dance, a ballroom dancing organization, has doubled to 20,000 members over the last decade. Dancing cheek to cheek to "Heart and Soul" doesn't have the intensity of rocking to "You Ain't Nothin' But a Hound Dog," but it has a soothing intimacy and emotional memory, and it can eliminate some of the 20,000 words that most couples can usually do without. Nature will out.