People live for love. They kill for love. They die for love. They have songs, poems, novels, sculptures, paintings, myths, legends. It's one of the most powerful brain systems on Earth for both great joy and great sorrow.

I think romantic love evolved to enable you to focus your mating energy on just one individual at a time, thereby conserving mating time and energy.

Research shows that couples who have a lot of similarities, including intellectual compatibility, end up staying together.

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.

Why do we feel jealousy? Therapists often regard the demon as a scar of childhood trauma or a symptom of a psychological problem. And it's true that people who feel inadequate, insecure, or overly dependent tend to be more jealous than others.

There are cognitive processes and limbic reactions associated with basic emotions. And you can change brain chemistry, but you're still not going to change memories and experiences in a human being.

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