This book takes readers inside the head of the kinds of malevolent people you know all too well, but could never understand. Starting with psychology as a frame of reference, it uses cutting-edge images of the working brain to provide startling support for the idea that 'evil' people act the way they do mainly as the result of a dysfunction. It is a tour de force of popular science writing that brilliantly melds scientific research with intriguing family history and puts both a human and a scientific face to evil.