Adolescence is the period of development that begins at puberty and ends at emerging adulthood; the typical age range is from 12 to 18 years, and this stage of development has some predictable psychosocial milestones. In the United States, adolescence is seen as a time to develop independence from parents while remaining connected to them. 

Adolescent Identity Exploration

Adolescence is the period of life known for the formation of personal and social identity. Adolescents must explore, test limits, become autonomous, and commit to an identity, or sense of self. Different roles, behaviors, and ideologies must be tried out to select an identity, and adolescents continue to refine their sense of self as they relate to others. Erik Erikson referred to the task of the adolescent as one of identity versus role confusion. Thus, in Erikson’s view, an adolescent’s main questions are “Who am I?” and “Who do I want to be?” Some adolescents adopt the values and roles that their parents provide them with; other teens develop identities that are in opposition to their parents but align with a peer group. This is common, as peer relationships become a central focus in adolescents’ lives.

Adolescents tend to be rather egocentric; they often experience a self-conscious desire to feel important in peer groups and receive social acceptance. Because choices made during adolescence can influence later life, higher levels of self-awareness and self-control in mid-adolescence will contribute to better decisions during the transition to adulthood. Three general approaches to understanding identity development include self-concept, sense of identity, and self-esteem.

Self-Concept

Early in adolescence, cognitive developments result in greater self-awareness. This leads to greater awareness of others as well as one's own thoughts and judgments. Adolescents develop the ability to think about abstract, future possibilities and consider multiple possibilities at once. They can conceptualize multiple possible selves that they could become, as well as long-term possibilities and consequences of their choices. Adolescents can begin to qualify their traits when asked to describe themselves. Differentiation occurs as an adolescent recognizes and distinguishes the contextual factors that influence their own behavior and the perceptions of others. Differentiation becomes fully developed by mid-adolescence.

The recognition of inconsistencies in the self-concept is a common source of distress during these years; however, this distress may benefit adolescents by encouraging further development and refinement of their self-concept.

Sense of Identity

Unlike the conflicting aspects of self-concept, identity represents a coherent sense of self that is stable across circumstances and includes past experiences and future goals. Erikson determined that "identity achievement" resolves the identity crisis in which adolescents must explore different possibilities and integrate different parts of themselves before committing to their chosen identity. Adolescents begin by defining themselves based on their membership in a group and then focus in on a personal identity. 

Self-Esteem

Self-esteem consists of one's thoughts and feelings about one's self-concept and identity. In the United States, children who are raised female are often taught that their sense of self is highly linked to their relationships with others; therefore, many adolescent girls enjoy high self-esteem when engaged in supportive relationships with friends. The most important function of friendship here is having someone who can provide social and moral support. Children who are raised as male, on the other hand, are often taught to value such things as autonomy and independence; therefore, many adolescent boys are more concerned with establishing and asserting their independence and defining their relation to authority. High self-esteem is often derived from their ability to successfully influence their friends.

Psychological Changes

During puberty, adolescents experience changes in the levels of certain neurotransmitters (such as dopamine and serotonin) in the limbic system. This affects the way in which they experience emotions, typically making them more emotional than younger children and adults and more sensitive to rewards and stress. 

Other cognitive developments have an impact on identity formation as well. When adolescents are able to think abstractly and reason logically, they have an easier time exploring and contemplating possible identities. When adolescents have advanced cognitive development and maturity, they tend to resolve identity issues more easily than peers who are less cognitively developed. 

Parental Relationships

As adolescents work to form their identities, they pull away from their parents, and the peer group becomes very important (Shanahan, McHale, Osgood, & Crouter, 2007). Despite spending less time with their parents, the type of relationship that adolescents have with their parents still plays a significant role in identity formation. Warm and healthy parent-child relationships have been associated with positive child outcomes, such as better grades and fewer school-behavior problems, in the United States as well as in other countries (Hair et al., 2005). When a solid and positive relationship exists, adolescents are more likely to feel freedom in exploring identity options. However, when the relationship is not as close or supportive and/or the adolescent fears rejection from the parent, the adolescent is more likely to feel less confident in forming a separate, personal identity.