Peer relations contribute substantially to both social and cognitive development. The essentials of friendship are reciprocity and commitment between individuals who see themselves more or less as equals. Affiliation and common interests, the main themes in friendship relations, are first understood in early childhood. Friends serve as emotional…

Current research on adolescence provides plenty of facts about delinquency, unemployment, and illegitimacy, yet tells us little or nothing about the inner life of adolescents. In an attempt to provide more information, the research reported on here describes the "periods" of adolescence as they are structured in the various…