Women are naturally prone to compete over their mates.

Scientists know that women gravitate to men who have a different immune system from theirs.

When you massage someone, the levels of oxytocin go up in the brain, and oxytocin is one of the chemicals that drives attachment.

Your sweetheart calls you by another's name. His eyes linger too long on your best friend. He talks with excitement about a girl at work. And the fire catches. Jealousy - that sickening combination of possessiveness, suspicion, rage, and humiliation - can overtake your mind and threaten your very core as you contemplate your rival.

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

We all have restlessness in long-term relationships.

We're not very dangerous animals; we don't have a horn like a rhino or quills like a porcupine.