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

Women are naturally prone to compete over their mates.

When somebody leaves Match.com or Chemistry.com, they ask you why you left. One box you can check is, 'I found somebody.' Between 15 and 20 percent of people check that box.

When you can't have someone but you're not willing to accept that, you try harder and become more extreme about it. Either you win the person back or you drive him away.

Men and women are like two feet; they can help each other get ahead.

Women, it turns out, are built to lead -- particularly in the modern world.

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.

Women have never been as interesting as they are now. Not at any time on this planet have women been so educated, so interesting, so capable.

There is more and more data indicating that there is a biological basis to your political views.

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.

Men with high baseline levels of testosterone marry less frequently, have more adulterous affairs, commit more spousal abuse, and divorce more often.

I've always maintained that men were more romantic than women.

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.

Hair that looks like it's been naturally sun-bleached makes you seem youthful, like you spend a lot of time outdoors. And that appeals to most people.

You don't come home from the office to spend time with another job. Hopefully you come home to someone you can have a good time with.

People have been looking for love potions since hunter-gatherer societies.

Blushing is thought to be linked to increased levels of norepinephrine in the brain, which may be associated with romantic feelings. It signals that we are interested and excited, which is attractive to men.

Men have a psychological need to show off their courage and strength. When he sees you talking to another guy, that instinct kicks in and he jumps to protect you and prove he's worthy of your love.

It's almost as if men who get tribal tattoos are trying to signal that they are dangerous, they're to be respected, and they're powerful.

When you look at the brain regions associated with picking up data from the body, a huge amount of the brain is devoted to picking up information from the lips and tongue.