The only people you and I are likely to know in common are people in the news - politicians, journalists and celebrities.

It's in our genes, we were built to wander.

The Internet lets women use words, which is their natural tool. Little girls speak in more complex, grammatical sentences than little boys do, and women never lose that superiority in verbal ability.

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.

Real competition can drive up testosterone, which boosts libido.

Of all the foods we share, there is nothing more primordial than meat. It's no surprise that meat-eaters still want a partner who will give, receive and share this primordial symbol of a budding partnership.

You size up someone physically in less than one second - too tall, too short, too fat, too thin, too old, too young, too stuffy, too scruffy.