Research shows that couples who have a lot of similarities, including intellectual compatibility, end up staying together.

Women are very attracted to a low voice because it's linked to testosterone, which for millions of years was a sign that men had very good spacial skills and would have been very good at hunting and finding their way back home.

The only people you and I are likely to know in common are people in the news - politicians, journalists and celebrities.

Romantic love allows you to focus mating energy. Attachment sustains that relationship as long as necessary to raise your baby.

Of all the foods we share, there is nothing more primordial than meat. It's no surprise that meat-eaters still want a partner who will give, receive and share this primordial symbol of a budding partnership.

You can get into a very fancy car and know everything about the engine, but when you drive in that car, you feel that rush. In the same way, I think the more you know about love, the more you can enjoy it. And knowing about your personality type, who you are and what kind of person you're dealing with gives you a great leg up.

Men and women are like two feet; they can help each other get ahead.