When you're in the throes of this romantic love, it's overwhelming - you're out of control, you're irrational, you're going to the gym at 6 A.M. every day - Why? Because she's there.
Any kind of novelty or excitement drives up dopamine in the brain, and dopamine is associated with romantic love.
Anthropologists have found evidence of romantic love in 170 societies. They've never found a society that did not have it.
Saliva has testosterone and estrogen. When you kiss, you're having a chemical experience.
Women have a better sense of smell than men do, and it's even sharper in the middle of their menstrual cycle, when estrogen levels peak and women are more likely to be deciding whether a man's attractive.
Women spend their lives trying to look good for men. So a woman who feels she's sending the right visual signals is pleased with herself.
People compose poetry, novels, sitcoms - for love.
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.
Real competition can drive up testosterone, which boosts libido.
Every time you cuddle with your children, you're likely to be driving down your testosterone.
When chimps threaten, they open their mouth and show their teeth. It's a little like waving a knife in front of you. It's very primitive, and therefore bizarre.
