We spend our lives trying to get along with people so we can keep our jobs, keep our marriages together, so that we can raise our kids properly.

Real competition can drive up testosterone, which boosts libido.

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.

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

The Great Depression of the 1930s saw more American unmarried women working from nine to five, mostly in repetitive, boring, subordinate, dead-end jobs. But the number of working women doubled between 1870 and 1940. During World War II it doubled once again.

The Internet lets women use words, which is their natural tool. Little girls speak in more complex, grammatical sentences than little boys do, and women never lose that superiority in verbal ability.