Another classic psychological account of adolescence can be found in the work of Erik Erikson, most notably in his book Identity: Youth and Crisis, published in 1968. Erikson’s developmental theory extends Piaget’s account of “ages and stages” into adulthood and old age. Each of his eight stages is characterized by a fundamental psychological conflict, whose successful resolution allows progression to the next stage. In the case of adolescence, the conflict is between identity and “role confusion.” Resolving this conflict involves finding a more or less settled role in life, and it results in the formation of a “virtue” (a form of psychological strength)—in this case, loyalty or fidelity—that enables the young person to progress to early adulthood and to form the intimate attachments that are the key tasks of that stage. Unsuccessful resolution results in a “maladaptation,” for instance in the form of fanaticism or a repudiation of adult responsibility.