We're apt to fall in love with those who are mysterious and challenging to us.

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.

When you look at the brain regions associated with picking up data from the body, a huge amount of the brain is devoted to picking up information from the lips and tongue.

From my studies of genetics and neuroscience I have come to believe that people fall into four broad personality types - each influenced by a different brain chemical: I call them the Explorer, Builder, Director, and Negotiator.

The only people you and I are likely to know in common are people in the news - politicians, journalists and celebrities.

There were real reasons that you were attracted to somebody originally. The brain doesn't pick willy-nilly. Unless you part ways hating each other for some reason, that mechanism could get triggered again. You can literally fall in love again.

You've got to remember that men are men and women are women. And although a lot of similarities, there are some real differences.