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.

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.

There exists no culture in which adultery is unknown, no cultural device or code that extinguishes philandering.

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.

Sometimes we fall in love with somebody who will probably never love us, for reasons having nothing to do with us but with their own mindset, their chemistry.

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

Almost always, when I'm on TV, the producers who call me, who negotiate what we're going to say, is a woman.