In Cruelty, neuroscientist Kathleen Taylor explores the factors behind violence, sexual abuse, genocide, and other atrocities. Drawing on history, politics, philosophy, psychology, and especially neuroscience, she sets cruelty in the context of human evolution and our current understanding of brain function. She begins with an example from Lithuania in World War II, in which a young man beat a group of prisoners to death, one by one, as a crowd of...