In adolescence, peer interactions are crucial in forging a self-identity (Damon, 1999). The peer group has various functions to a teenager. The group acts as an extended family for most young people. Within this group social lessons are tested prior to using these newfound skills with others outside of the youngsters' comfort zone. If a teenager is self-conscious or is having identity or sexual issues, he is most likely to test the waters within this close net group of friends. In contrast, this group can also use this social forum in a negative way.
A teen that discourages the peer group members with which he is associated can be ousted over an action or a suspected action. This will lead to rejection from the group. For instance, when a piece of information sensitive to only the group's members escapes and confidence is broken, the person responsible will be shunned by the group. This can lead to several forms of depression such as emotional distress and physiological irritation. Another negative influence of peer groups is peer pressure. A teenager who is not part of a peer group may deviate from her normal behavior pattern in order to obtain acceptance into a particular group. Actions like defiant behavior in a classroom, talking back to authoritative individuals, and ridiculing a fellow student are activities that can be practiced in order to fit in.