What our grandmothers told us about playing hard to get is true. The whole point of the game is to impress and capture. It's not about honesty. Many men and women, when they're playing the courtship game, deceive so they can win. Novelty, excitement and danger drive up dopamine in the brain. And both sexes brag.

Women like signs of money and education - things that indicate that not only is this guy going to have some resources, but he's also willing to share them.

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.

The main characteristics of romantic love are craving: an intense craving to be with a particular person, not just sexually, but emotionally.

We all have restlessness in long-term relationships.

There's all kinds of reasons that you fall in love with one person rather than another: Timing is important. Proximity is important. Mystery is important. You fall in love with somebody who's somewhat mysterious, in part because mystery elevates dopamine in the brain, probably pushes you over that threshold to fall in love.

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