This book discusses the crucial role of social networks in the development of adolescents and young adults between the ages of twelve and twenty-five years. It looks at how young people's relationships shape their behaviour and identity, and the consequences of peer influence on health risk, antisocial behaviour and school motivation. John Cotterell draws on both social and psychological research to apply network thinking to the social relationships and experiences of young people in school, work and society. Network thinking examines the pattern and nature of social ties. It analyses how the structure of networks and organizations channel information, influence and support with effects on health, motivation, and career opportunities. The book comprises ten chapters, arranged in three sections: networks, influences, and support. Each chapter contains discussion on a key topic, such as youth transitions, peer structures, friendship, romantic ties, loneliness, peer rejection, smoking, drinking, delinquency, anti-social behaviour, youth risk-taking, school motivation, career influence, youth citizenship, and community organizations for young people. their changing configurations, and the forces of influence they unleash. It contains a discussion of some of the practical ways in which schools can provide supports, and suggests how youth organizations and communities can assist young people to become effective citizens.