Over a hundred years of anthropological studies have demonstrated that religion is a fundamental and pervasive aspect of all human societies. Human beings appear to be inherently religious. But why? Religious practices determine the outcome of the struggle for existence and affect reproductive success. From an evolutionary perspective, such behaviours must bring biologically adaptive benefits, or the culling hand of Darwinian evolution would have eliminated religion long ago. In his unique analysis of religion, biologist Kenneth V Kardong argues that, in a prescientific world, religion was an evolutionary necessity for human survival. Going beyond the recognised psychological comforts of religion as a remedy for emotional insecurity and anxiety, Kardong instead explores what survival advantages religion first conferred on those humans faithfully practising a locally adaptive set of cults and customs.By focusing on religion's survival advantages, he is then able to address why religion evolved in the first place and why it possesses some of the distinctive and occasionally troubling characteristics we see today. Kardong concludes that because religion was adaptive it is still planted deep within us and in our future. These ancient religious impulses are often unyielding when confronted by our comparatively recent capacity for rational and scientific understanding. This intractable quality in certain contexts can lead to violence and the other evils that throughout history and today serve as the worst examples of religious behaviour. This book makes an important contribution to the understanding of religion from an evolutionary perspective.