Good-looking people are always looking for other good-looking people.

Women, it turns out, are built to lead - particularly in the modern world.

It certainly would have been adaptive for ancestral man to have a chubby wife during stressful times of famine. Not only would she have had more calories to burn, and thus more energy and endurance, but since fat stores estrogen, she would have remained fertile for longer.

Men have a psychological need to show off their courage and strength. When he sees you talking to another guy, that instinct kicks in and he jumps to protect you and prove he's worthy of your love.

There is more and more data indicating that there is a biological basis to your political views.

When you're in the throes of this romantic love, it's overwhelming - you're out of control, you're irrational, you're going to the gym at 6 A.M. every day - Why? Because she's there.

Women are better at reading body language everywhere in the world. As a matter of fact, it's associated with the female hormone estrogen. Women are better at figuring out of tone of voice, reading your face and posture and gesture.