An award-winning psychologist draws on years of research to unveil "a simple but persuasive hypothesis for a new way to think about evil" (New York Times). How can we explain both cruelty and kindness? To award-winning psychologist Simon Baron-Cohen, the explanation for cruelty is low levels of empathy, and the explanation for kindness is high levels of empathy. In The Science of Evil, Baron-Cohen draws on decades of research to develop a new, brain-based theory of human cruelty and kindness. He explores the social and biological factors that can influence our empathy levels, explains the key distinction between cognitive and affective forms of empathy, and shows how low empathy can lead to dehumanizing behavior. Updated with a new introduction by the author, The Science of Evil will continue to challenge our understanding of human cruelty.