'Unsaid Chemistry': Science of Seduction

Jan. 30, 2009— -- Biological anthropologist Helen Fisher, who has spent a lifetime studying how and why we fall in love, says there is a science to the art of seduction, but it's never simple.

Fisher's research has taught her that "romantic love is not an emotion. It's a basic mating drive. A motivation system. A system to try to win life's greatest prize, which is the right mating partner."

The author of "Why Him, Why Her?" teamed up with the dating Web site Chemistry.com to try to understand that system -- to determine why we fall in love with one person rather than another.

"What I had to do," she said, "is figure out if there was any biology to your behavior."

Fisher began an exhaustive review of the scientific literature and eventually came to believe that there were four broad biological personality types associated with four specific neurotransmitters and hormones: dopamine, serotonin, testosterone and estrogen.

Fisher suspects we are all some combination of these four types, which she has named the explorer (risk-taking, associated with dopamine), the builder (calm, traditional, associated with serotonin), the director (analytical, tough-minded and decisive, associated with testosterone) and the negotiator (emotionally expressive and empathetic, associated with estrogen).

"So I looked at these four chemical systems and I thought to myself, maybe you could create a questionnaire to see to what degree we express each of these," she said. "And if I could create a questionnaire that could establish who you are, and then on a dating site, watch which biological type is drawn to which other biological type, I might come closer to understanding why him, why her."

To date, 7 million people worldwide have taken the questionnaire, including four couples that "20/20" followed as they embarked on new relationships. "20/20" would pick up the tab for their dates, but would any of them find lasting love?

Go to WhyHimWhyHer.com to take Fisher's complete questionnaire.