Anthropologists have found evidence of romantic love in 170 societies. They've never found a society that did not have it.

Men want to think women don't cheat, and women want men to think they don't cheat, and therefore the sexes have been playing a little psychological game with each other.

Romantic love is an addiction: a perfectly wonderful addiction when it's going well, and a perfectly horrible addiction when it's going poorly.

It's in our genes, we were built to wander.

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.

Saliva has testosterone and estrogen. When you kiss, you're having a chemical experience.

Women are better at reading body language everywhere in the world. As a matter of fact, it's associated with the female hormone estrogen. Women are better at figuring out of tone of voice, reading your face and posture and gesture.