a phase of life marked by experimentation; changing, conflicting, or newly emerging values; and a lack of commitment to one’s usual roles in society (especially in work and family relationships). Erik Erikson claimed that it is natural and desirable for adolescents to go through a period of identity crisis and that greater maturity results from the experience. The concept has been expanded to refer to adult midlife crises and other periods marked by change or uncertainty about the self. See ego identity.