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

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.

When chimps threaten, they open their mouth and show their teeth. It's a little like waving a knife in front of you. It's very primitive, and therefore bizarre.

[Women] tend to collect more pieces of data when they think, put them into more complex patterns, see more options and outcomes. They tend to be contextual, holistic thinkers.

When you massage someone, the levels of oxytocin go up in the brain, and oxytocin is one of the chemicals that drives attachment.

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.

The reason you take antidepressants is to feel calm. And romantic love is not calm -it's elation, it's mood swings, and you're killing all that when you take the drug.