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

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

Liberals and conservatives are looking for entirely different things. Their attitudes toward romance and how they court are really dramatically different. There's almost no overlap.

People compose poetry, novels, sitcoms - for love.

Women are very attracted to a low voice because it's linked to testosterone, which for millions of years was a sign that men had very good spacial skills and would have been very good at hunting and finding their way back home.

You size up someone physically in less than one second - too tall, too short, too fat, too thin, too old, too young, too stuffy, too scruffy.

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.