What does modern warfare have in common with our human evolution? In this study, Dr Kenneth Payne argues that there is an important relationship between the two - we have evolved to fight, and traditional hunter-gatherer societies were often violent places. But we also evolved to cooperate and to behave altruistically towards others. Both these evolutionary legacies can help explain how and why liberal societies fight. Payne considers the evidence for warfare in hunter gatherer communities, and explores how a process of 'domestication' some 10,000 years ago led to larger groups of more social and culturally sophisticated humans. He then considers how this über-sociability is manifest in liberal societies in the modern era, underpinning our sense of empathy and moral values.