It remains something of a mystery why some individuals behave in persistently malevolent and destructive ways towards their fellows, causing untold harm both to themselves and their victims. This book argues that to understand the roots of antisocial behaviour, one first has to understand what motivates the majority of people to behave prosocially - to think, feel and act in non-malevolent ways. All people are motivated to seek emotion goals - to feel thrilled and excited, to feel safe from the threats of others, to feel a sense of justice, and to feel gratified. However some individuals seek these emotion goals in antisocial ways due to an excess of emotions such as distrust, boredom, greed, vengeance and insecurity. The authors outline interpersonal and neurobiological correlates of antisocial personality, its developmental antecedents, its frequency and pattern across different societies and cultures, and different approaches to its treatment and rehabilitation.