From my studies of genetics and neuroscience I have come to believe that people fall into four broad personality types - each influenced by a different brain chemical: I call them the Explorer, Builder, Director, and Negotiator.

People have often asked me whether what I know about love has spoiled it for me. And I just simply say, 'Hardly.' You can know every single ingredient in a piece of chocolate cake, and then when you sit down and eat that cake, you can still feel that joy.

You fall in love with somebody who fits within what I call your 'love map,' an unconscious list of traits that you build in childhood as you grow up. And I also think that you gravitate to certain people, actually, with somewhat complementary brain systems.

I think the happiness we find, we make.

Almost always, when I'm on TV, the producers who call me, who negotiate what we're going to say, is a woman.

Women spend their lives trying to look good for men. So a woman who feels she's sending the right visual signals is pleased with herself.

Touch is the mother of the senses. Not only are women more sensitive when they touch, but they're also more sensitive to being touched.

Women like signs of money and education - things that indicate that not only is this guy going to have some resources, but he's also willing to share them.

Women have a better sense of smell than men do, and it's even sharper in the middle of their menstrual cycle, when estrogen levels peak and women are more likely to be deciding whether a man's attractive.

When you can't have someone but you're not willing to accept that, you try harder and become more extreme about it. Either you win the person back or you drive him away.

If two very different people pool their DNA, they'll create more genetic variety, and their young will come to the job of parenting with a wider array of skills.

We're apt to fall in love with those who are mysterious and challenging to us.

A woman of 40 or 50 or 60 can take estrogen replacements, get facelifts, spend her money in bars.

In courtship, who wins and who loses will determine who passes on their DNA to tomorrow.

Like most animals, we're wired to associate height with power.

We still have community, but we don't seem to have local community. Even in a small town where you know your neighbors and your mother's down the street, they're not in arm's length.

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.

We all have restlessness in long-term relationships.

Men tend to be hierarchical, but women are driven to make lateral connections so they can cooperate.

The Internet lets women use words, which is their natural tool. Little girls speak in more complex, grammatical sentences than little boys do, and women never lose that superiority in verbal ability.

I've always maintained that men were more romantic than women.

The women's movement is just a symptom of basic changes in the economy that are favoring women.

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.

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