Laws of Attraction

In this CBS clip from the series Medical Mysteries, we meet with Jena Pincott who began studying the chemistry of romance.

She wrote a book called Do Gentleman Really Prefer Blondes? and discovered that men are less likely to follow their sense of smell to base attraction. A new DNA matchmaking service, ScientificMatch.com, is designed to match men and women based on chemical makeup.

Jena and Peter are a perfect chemical match based on an algorithm. Jena explains that opposites attract. How does Jena explain that opposites attract? How did Helen Fisher explain it?