There's got to be somepart of our mind that came out our nature. I know that because I'm in a twin, an identical twin. And so when it came to writing my PhD dissertation. I thought to myself if there's any part of human behavior that has a biological origin. It must be our patterns of love and marriage. Because as Darwin would have said, if you have four children and I have no children, You live on and I die out. The game of love matters. And so you would think there would have been selection for all kinds of behaviors that would enable you to fall in love with somebody, form a partnership and raise your babies as a team. And so that's why I started to study love, And you know people will often think, "Well she studied love because had a bad relationship in high school" Well, nobody gets out of love alive. We all have problems with love. But that did not stimulate me to study romantic love. It was simply because I was an identical twin. And I w...