When people tell you to walk a certain way, it's like not thinking of a purple tomato. You can't not do it.

Globalization requires taking a broad contextual and long-term view.

Jealousy can even be good for love. One partner may feel secretly flattered when the other is mildly jealous. And catching someone flirting with your beloved can spark the kind of lust and romance that reignites a relationship.

Romantic love is an obsession. It possesses you. You lose your sense of self. You can’t stop thinking about another human being.

Along with our many human propensities, we evolved a huge cerebral cortex with which we make decisions.

Both sexes like the exercise and challenge of sports, but for men it's also a basic display behavior for impressing and winning a mate.

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.