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

Research shows that couples who have a lot of similarities, including intellectual compatibility, end up staying together.

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.

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.

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.

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.

I think romantic love evolved to enable you to focus your mating energy on just one individual at a time, thereby conserving mating time and energy.