From caveman to modern man . . . Few people doubt that humans are descended from the apes; fewer still consider, let alone accept, the psychological implications. But in truth, man not only looks, moves and breathes like an ape, he also thinks like one. Sexual drive, survival, competition, aggression - all of our impulses are driven by our human instincts. They explain why a happily married man will fantasize about the pretty, slim, young woman sitting...