In psychology, identity crisis is a stage in Erik Erikson's theory of personality development. This stage happens during adolescence. It is a period of deep reflection and examination of various perspectives on oneself.

The stage of psychosocial development in which identity crisis may occur is called identity cohesion vs. role confusion. During this stage, adolescents are faced with physical growth, sexual maturity, and integrating ideas of themselves and about what others think of them. They therefore form their self-image and endure the task of resolving the crisis of their ego identity. Successful resolution of the crisis depends on one's progress through previous developmental stages, centering on issues such as trust, autonomy, and initiative.

Erikson's interest in identity began in childhood. Born Ashkenazi Jewish, he felt that he was an outsider. His later studies of cultural life among the Yurok of northern California and the Sioux of South Dakota helped formalize his ideas about identity development and identity crisis. Erikson described those going through an identity crisis as exhibiting confusion.

Adolescents may withdraw from normal life, not taking action or acting as they usually would at work, in their marriage or at school, or be unable to make defining choices about the future. They may even turn to negative activities, such as crime or drugs since from their point of view having a negative identity could be more acceptable than none at all. On the other side of the spectrum, those who emerge from the adolescent stage of personality development with a strong sense of identity are well equipped to face adulthood with confidence and certainty.

Erikson studied eight stages that made up his theory. To him, ego identity is a key concept to understanding what identity is, and it plays a large role in the conscious mind that includes fantasies, feelings, memories, perceptions, self-awareness, sensations, and thoughts; Each contributing a sense to self that is developed through social interaction. He felt that peers have a strong impact on the development of ego identity during adolescence. He believed that association with negative groups such as cults or fanatics can actually "redistrict" the developing ego during this fragile time.

The basic strength that Erikson argued should be developed during adolescence is fidelity, which only emerges from a cohesive ego identity. Fidelity encompasses sincerity, genuineness and a sense of duty in relationships with other people. Erikson defined the crisis as an argument between identity and confusion. Confusion lies between the younger generation, teenagers, and during adolescence he states that they "need to develop a sense of self and personal identity". If they do not develop this sense, they will be insecure and lose themselves, lacking confidence and certainty in adult life.

He described identity as "a subjective sense as well as an observable quality of personal sameness and continuity, paired with some belief in the sameness and continuity of some shared world image. As a quality of unself-conscious living, this can be gloriously obvious in a young person who has found himself as he has found his commonality. In him we see emerge a unique unification of what is irreversibly given—that is, body type and temperament, giftedness and vulnerability, infantile models and acquired ideals—with the open choices provided in available roles, occupational possibilities, values offered, mentors met, friendships made, and first sexual encounters."

James Marcia's research on identity statuses of adolescents also applies to Erikson's framework of identity crises in adolescents.