Romantic love is an addiction.

Until recently, we regarded love as supernatural. We were willing to study the brain chemistry of fear and depression and anger but not love.

Natural beauty really entices men. They will tell you this time and time again, and studies consistently prove it.

When you fight, anger drives up testosterone in both men and women.

I've always maintained that men were more romantic than women.

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.

In general, men are wired to notice obvious signs that convey interest in mating - a warm smile, for example - and ignore other subtleties, like if your lipstick is faded.

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.

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.

Any kind of novelty or excitement drives up dopamine in the brain, and dopamine is associated with romantic love.

Psychologists maintain that the dizzying feeling of intense romantic love lasts only about 18 months to - at best - three years.

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.