Romantic love is an obsession. It possesses you. You lose your sense of self. You can’t stop thinking about another human being.

There's biology in everything, even when you're feeling spiritual.

Women's worst invention was the plow. With the beginning of plow agriculture, men's roles became extremely powerful. Women lost their ancient jobs as collectors.

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.

Young women today do not marry the men they met in high school, or even the one they go out with at college, because they do not need to.

You fall in love with somebody who fits within what I call your 'love map,' an unconscious list of traits that you build in childhood as you grow up. And I also think that you gravitate to certain people, actually, with somewhat complementary brain systems.

Whether you're married or not, relationships - and the satisfaction tied to them - are extremely important for increasing men's and women's quality of life.