Why not kill them all?

the long version

"Cowritten by historical sociologist Daniel Chirot and psychologist Clark McCauley, the book goes beyond exploring the motives that have provided the psychological underpinnings for genocidal killings. It offers a historical and comparative context that adds up to a causal taxonomy of genocidal events. Rather than suggesting that such horrors are the product of abnormal or criminal minds, the authors emphasize the normality of these horrors: killing by category has occurred on every continent and in every century. But genocide is much less common than the imbalance of power that makes it possible. Throughout history human societies have developed techniques aimed at limiting intergroup violence. Incorporating ethnographic, historical, and current political evidence, this book examines the mechanisms of constraint that human societies have employed to temper partisan passions and reduce carnage."--Jacket.