"Multilevel selection is the only logically coherent and empirically supported theory that can explain human ultrasociality-the capacity of humans to cooperate in huge groups of genetically unrelated individuals. Yet influential critics continue to reject it. This timely and important book is a welcome entrant to this intense scientific debate. The stakes are high, because understanding how cooperation evolved and can be maintained is key to solving the Tragedy of the Commons problems at both local and global levels." - Peter Turchin, author of Ultrasociety (2015) and Professor at the University of Connecticut, USA This book embeds a novel evolutionary analysis of human group selection within a comprehensive overview of multilevel selection theory, a theory wherein evolution proceeds at the level of individual organisms and collectives, such as human families, tribes, states, and empires. Where previous works on the topic have variously supported multilevel selection with logic, theory, experimental data, or via review of the zoological literature; in this book the authors uniquely establish the validity of human group selection as a historical evolutionary process within a multilevel selection framework. Select portions of the historical record are examined from a multilevel selectionist perspective, such that clashing civilizations, decline and fall, law, custom, war, genocide, ostracism, banishment, and the like are viewed with the end of understanding their implications for internal cohesion, external defense, and population demography. In doing so, its authors advance the potential for further interdisciplinary study in fostering, for instance, the convergence of history and biology. This work will provide fresh insights not only for evolutionists but also for researchers working across the social sciences and humanities. Steven C. Hertler is a licensed examining psychologist and Adjunct Professor of Psychology at the College of Saint Elizabeth, USA. Aurelio José Figueredo is Professor of Psychology, Family Studies and Human Development at the University of Arizona, USA. Dr. Figueredo also serves as Director of the Ethology and Evolutionary Psychology (EEP) Laboratory. Mateo Peñaherrera-Aguirre is a Ph.D. candidate in the Cognitive and Neural Systems Program and a researcher at the University of Arizona, USA.