react with retributive violence, and gang formation or membership is often not far behind (Prothrow-Stith and Weissman, 1991). A high prevalence of violence changes the social norms of a community. Even when a community program is safe, getting to and from it without risk is critical.

In conclusion, physical and psychological safety are prerequisites to all the categories of positive development we described in the last chapter. In addition to the direct effects of harm on physical well-being and development, violence or the threat of violence interferes with the allocation of attention to intellectual, psychological, emotional, and social development. They create psychological trauma that requires adolescents to cope in maladaptive ways, psychologically, emotionally, and behaviorally.

One of the first things a new participant experiences in a community program for youth is whether the environment is structured or chaotic. According to theories and empirical research, development requires that a child experience a stable, predictable reality. Cognitive theories (Piaget, 1964, 1971; Piaget and Inhelder, 1973) stress the need for a stable environment to which children can assimilate and accommodate their emerging cognitive structures; object relations theorists also stress the predictabil-