As societies continue to loosen their standards regarding what is appropriate female and male behavior, I think we are going to realize we have not only underestimated women, but also men.

People live for love. They kill for love. They die for love. They have songs, poems, novels, sculptures, paintings, myths, legends. It's one of the most powerful brain systems on Earth for both great joy and great sorrow.

The human brain is built to compare; it's Darwinian to consider an alternative when one presents itself.

Women are naturally prone to compete over their mates.

Until recently, we regarded love as supernatural. We were willing to study the brain chemistry of fear and depression and anger but not love.

If two very different people pool their DNA, they'll create more genetic variety, and their young will come to the job of parenting with a wider array of skills.

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.