Jealousy can even be good for love. One partner may feel secretly flattered when the other is mildly jealous. And catching someone flirting with your beloved can spark the kind of lust and romance that reignites a relationship.

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

A world without love is a deadly place.

Kissing is not just kissing. It is a major escalation or de-escalation point in a powerful process of mate choice.

The reason you take antidepressants is to feel calm. And romantic love is not calm -it's elation, it's mood swings, and you're killing all that when you take the drug.

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

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.