Oliver Sacks has described Sapolsky as 'one of the best scientist-writers of our time.' This superb guide to human nature shows how all the perspective and systems connect and we laugh and marvel along the way on this beautifully crafted work about the biology of morality. Sapolsky's own research and his vast knowledge of the neurobiology, genetic and behavioural literature reflects in this magisterial and extraordinary survey on the science of human behaviour. Why do human beings behave as they do? We are capable of savage acts of violence but also spectacular feats of kindness. Is one side of our nature destined to win out over the other? Every act of human behaviour has multiple layers of causation, spiralling back seconds, minutes, hours, centuries back to the origin of our species. In this epic sweep of history, how does our biology affect the arc of war and peace, justice and persecution? How have our brains evolved alongside our cultures? Sapolsky takes us back to the womb, to the fertilized egg, the evolution of behaviour, us versus them, hierarchy, obedience and resistance, morality and doing the right thing, feeling someone's pain, the criminal justice system and free will. He explains that we don't hate violence we just hate and fear the wrong kind of violence, violence in the wrong context. He looks at the behaviours and impulses behind the acts of individuals, groups and states, good or bad and what biology teaches us about cooperation, affiliation, reconciliation, empathy and altruism. Well illustrated softback, 790pp, extensive notes (in tiny print).