Love on the Brain

He's analytical, driven, not very verbal, and not always compassionate.

She's gregarious, intuitive, whimsical, warm, and compassionate.

Before you say "not a chance," hear another view.

It's probably a good match, says Helen Fisher, PhD, a cultural anthropologist from Rutgers University and a leading researcher on love, attraction, and romance. One of her findings: Biology matters, and these two people's biology -- their chemical "profiles" -- may complement each other nicely.

In recent years, Fisher and a host of other researchers have been looking deep into our psyche and brains -- helped by high-tech imaging and genetic analysis. They've come up with some intriguing information about what makes us become attracted to someone, what underlies the crazy-in-love feeling, what's up with the transition from butterflies to a more comfortable relationship, and what keeps us attracted.

"It's all much less of a mystery than it was five years ago and certainly 30 years ago," says Arthur Aron, PhD, a professor of psychology at the State University of New York at Stony Brook and another top researcher in the field. The science of the biology of love is relatively new. Research picked up steam in the 1980s, Aron says, and since then experts have made multiple discoveries. Here's a sampling of their findings:

The Biology of Love: Biology Matters

When it comes to whom you are attracted to, "your biology plays a role,'' says Fisher, who wrote Why We Love and several other books. It's not only a similar socioeconomic status, level of education and family backgrounds that make people attractive to you, she says, but also hormones -- ones that differ from your own.

We're attracted, Fisher says, to those with a chemical "profile" for estrogen, testosterone, dopamine, and serotonin that's different from our own, yet complements it. For instance, she says, "If you tend to be high estrogen, you will gravitate to the high testosterone type.''

That explains why Mr. Analytical and Driven and Ms. Gregarious and Warm are a match. He's probably a ''high testosterone'' type, Fisher says, and she is probably a "high estrogen" type. "For good Darwinian reasons, they are very complementary," says Fisher. She can likely see many ways of doing things and become indecisive. To the rescue, the analytical man. Likewise, she might inspire more compassion in him. Fisher is working with chemistry.com, an offshoot of match.com, to develop this chemical profile match strategy.

The Biology of Love: Your Brain in Love

Love involves three basic brain circuits, according to Fisher. There's the sex drive, which motivates us to seek out partners; romantic love, the in-the-clouds feeling when you first fall in love; and the attachment phase, the comfortable-but-fewer-fireworks stage.

"The sex drive is a very simple drive," Fisher says. "It's simply the craving for sexual gratification, driven largely by testosterone in both men and women."