Book excerpt: An effective gang intervention programme, Aggression Replacement Training (ART), is the subject of this book. Rearrest rates and other outcome results support the success of a project using the ART intervention approach with a series of very aggressive juvenile gangs in New York. Working with gangs as a unit, the goal was not only to teach them anger control and other skills, but to do so in such a way that their real-world reference group (the gang) was turned, as much as possible, into a prosocial rather than an antisocial support group. In addition, the book provides a thorough introduction to the history of gangs, current gang demographics, gang aggression and its etiology, as well as a review an