The brain was not built to walk into a bar, where you know nobody, and start a conversation. That's not the way humanity has courted.

Sometimes we fall in love with somebody who will probably never love us, for reasons having nothing to do with us but with their own mindset, their chemistry.

Today, most women are surrounded by ingenious gadgets. They don't grow the peas or raise the chicken that they serve for dinner; instead they hunt and gather in the grocery store. They go through catalogs or department stores to buy clothes instead of shearing sheep, carding wool, and weaving cloth for skirts and coats and blankets.

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

Mothers really were not built to raise babies not only by themselves, but with only a partner. For millions of years, a woman had much more than just her husband to help rear her young... This whole idea of 'it takes a village to raise a child' is exactly how we're supposed to live.

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.

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