It may not always seem so, but day-to-day interactions between individual humans are extraordinarily peaceful. That is not to say that we are perfect, just far less violent than most animals, especially our closest relatives, the chimpanzee and their legendarily docile cousins, the Bonobo. Perhaps surprisingly, we rape, maim, and kill many fewer of our neighbours than all other primates and almost all undomesticated animals. But there is one form of violence that humans exceed all other animals in by several degrees: organised proactive violence against other groups of humans. It seems, we are the only animal that goes to war. In The Goodness Paradox, Richard Wrangham wrestles with this paradox at the heart of human behaviour. Drawing on new research by geneticists, neuroscientists, primatologists, and archaeologists, he shows that what domesticated our species was nothing less than the invention of capital punishment which eliminated the least cooperative and most aggressive among us. But that development is exactly what laid the groundwork for the worst of our atrocities.