The world of the 2020s is one where instability, war and societal breakup seem close. But, surely, we have learnt the lessons of the past? Surely, peace will continue? Are you sure? Do you even know what causes wars? Mike Martin argues that we don't understand what causes violence and conflict, let alone how to go about solving these problems. But there is a way to make sense of war and society: linking the evolution of our brains with our history of social development, 'Why We Fight' shows how political dynamics, violence between individuals and, above all, war between groups are all caused by deep-seated, unconscious urges to seek status and belonging. Weaving together evolution, personal experiences of war, and more than a decade of studying conflicts around the world, 'Why We Fight' will change the way you think about society, about war, and about yourself. It is a blueprint for the turbulent 2020s.