"Hruschka's integrative approach provides a robust, and accessible, view of the complexities of making, having, and being friends. This kind of inquiry is at the forefront of modern biocultural anthropology."--Agustin Fuentes, author of Evolution of Human Behavior "Despite its importance to human happiness and well-being, friendship has long been a puzzle--largely a neglected one--for evolutionary scholars. Daniel Hruschka's book is a long overdue remedy to this situation. Through a deft combination of rigorous analysis and fine writing, Hruschka provides a thorough examination of friendship across the full range of human societies, past and present. His book will be an essential starting point for future work on this important topic."--Lee Cronk, author of That Complex Whole: Culture and the Evolution of Human Behavior "With Friendship, Dan Hruschka uses evolutionary science to breathe new life into a topic that is vastly important and woefully misunderstood. Remarkable for its scope, insightfulness, and clarity, this book will change how we think about friendship for years to come."--Michael McCullough, author of Beyond Revenge: The Evolution of the Forgiveness Instinct