From a scientist and writer E.O. Wilson has called "the world authority on primate social behavior" comes a fascinating look at the most provocative aspects of human nature through our two closest cousins in the ape family. From "one of the world's greatest experts on primate behavior" (Desmond Morris) comes a look at the most provocative aspects of human nature-power, sex, violence, kindness, and morality-through our closest cousins. For nearly twenty years, Frans De Waal has studied both the famously aggressive chimpanzee and the egalitarian, matriarchal bonobo, two species whose DNA is nearly identical to ours. The result is an engrossing narrative that reveals what their behavior can teach us about ourselves.