Our nation's youth are at risk for drug and alcohol abuse, unsafe sexual practices, teen pregnancy, academic underachievement, delinquency, and crime and violence. What can be done to prevent these problems from occurring? Outlining a vigorous "call to arms," this volume describes the steps needed to overcome these potential problems by enhancing academic researchers' responsiveness to the needs of the community and encouraging them to apply the results of research findings to community outreach. After reviewing the problems that beset today's youth, Lerner offers a model - developmental contextualism - that provides a theoretical framework for viewing child and adolescent development in relation to specific features of environmental "context," such as family, neighborhood, society, and culture. This model is used to describe the problems and the potentials that are associated with the bidirectional relationships between youth and their contexts. Lerner asserts that, by altering the context in which youth live, researchers can test the effectiveness of policies and/or programs in creating desired changes in children's and adolescents' behavior and development.