Gender norms refer to the collective set of social attitudes and beliefs that determine the appropriate [Page 698]values, motives, and behaviors for males and females within a given culture. Gender norms are influenced by biological, cognitive, and contextual factors. Because adolescence is an important period of personal identity formation, gender norms play an integral role in shaping adolescent gender identity. This entry examines contemporary gender norms in adolescence using a developmental and cross-cultural lens and discusses current research trends in gender nonconformity as well as the psychosocial consequences facing adolescents who break traditional gender norms.