As women in industrial societies join the paid workforce, they gain the economic means to depart unhappy marriages more easily.

I don’t think we’re an animal that was built to be happy; we are an animal that was built to reproduce.

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.

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.

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.

Women like signs of money and education - things that indicate that not only is this guy going to have some resources, but he's also willing to share them.

There's magic to love... Millions of years ago we evolved three basic drives: the sex love, romantic love, and attachment to a long-term partner. These circuits are deeply embedded in the human brian. They're going to survive as long as our species survive on what Shakespeare called, this "mortal coil."