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 are very attracted to a low voice because it's linked to testosterone, which for millions of years was a sign that men had very good spacial skills and would have been very good at hunting and finding their way back home.

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

You've got to remember that men are men and women are women. And although a lot of similarities, there are some real differences.

We evolved in a tropical climate where the smells of plants and flowers were all around us. We spent a lot of time in the trees with a lot of sunlight and no clothes.

Barriers tend to intensify romance. It's called the 'Romeo and Juliet effect.' I call it 'frustration attraction.'

The brain was not built to walk into a bar, where you know nobody, and start a conversation. That's not the way humanity has courted.