Peer groups shape identity during adolescence through multiple social processes. As teens seek belonging and autonomy, peers become a major reference point for how to act, talk, dress, and think. They provide social support that helps them feel validated and understood, which strengthens a sense of self. Peers also model behavior—teens imitate what their friends do, from everyday manners to larger choices about interests and conduct—so norms within the group become a guide for their own attitudes and actions. At the same time, peers can challenge parental norms, offering alternative viewpoints and possibilities for self-definition that parents may not present. This dynamic can push adolescents to explore different identities, styles, and values as part of forming who they are. Peer groups can encourage risk-taking or promote conformity, depending on the group’s norms, which helps explain shifts in behavior, fashion, slang, and tastes during adolescence. In short, identity formation in this period is deeply intertwined with how peers influence emotions, behaviors, preferences, and social presentation across various aspects of life.