We're not very dangerous animals; we don't have a horn like a rhino or quills like a porcupine.

When you fight, anger drives up testosterone in both men and women.

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.

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

Men are so visual, they see a woman who appeals to them physically, and it will trigger the romantic love system faster.

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

My hypothesis is that conservative Republicans have very clear values, and when you have that, you're simply more relaxed.