Video: Leading primatologist Frans DeWaal is the author of this book. He is an expert on our closest remaining evolutionary relatives, the chimpanzee and the bonobo. Separated seven million years ago, humans and chimps are genetically almost identical. Like chimps we cooperated to hunt and share our food. Like chimps, we can be very ruthless towards individuals who are not part of our troop. Like bonobos we are sexually turned on all the time and sexually obsessed. Chimps are violent. And so are we. Looking at them gives us a mirror into our own souls.