Erikson’s stage of identity versus identity confusion recognizes the formation of a coherent set of values and life plans as the major personality achievement of adolescence. The development of an organized self-concept and more differentiated sense of self-esteem is affected by several factors, including abstract reasoning and family, school, and community contexts. Changes in self-concept and self-esteem prepare the young person for constructing an identity. Adolescents vary in their degree of progress toward developing a mature identity. Identity achievement and moratorium are adaptive statuses associated with positive personality characteristics. Teenagers who remain in identity foreclosure or identity diffusion tend to have adjustment difficulties.

According to Kohlberg, morality changes from concrete, externally controlled reasoning in late childhood to more abstract, principled justifications for moral choices in adulthood. A broad range of family, school, peer, and cultural factors foster moral development. As individuals advance through Kohlberg’s stages, moral reasoning becomes more closely related to behavior.

Biological, social, and cognitive forces combine to make early adolescence a period of gender intensification. Over the adolescent years, relationships with parents and siblings change as teenagers strive to establish a healthy balance between connection to and separation from the family. As adolescents spend more time with peers, intimacy and loyalty become central features of friendship. Adolescent peer groups are organized into tightly knit groups called cliques, and as teenagers become interested in dating, several cliques come together to form a crowd. Although peer pressure rises in adolescence, most teenagers do not blindly conform to the dictates of agemates.

Although most young people move through adolescence with little difficulty, a few encounter major disruptions in development. Depression is the most common psychological problem of the teenage years, influenced by a diverse combination of biological and environmental factors. The suicide rate increases dramatically at adolescence. Many teenagers become involved in some delinquent activity, but only a few are serious or repeat offenders. Family, school, peer, and neighborhood factors are related to delinquency.