The first of the two traditional models, the psychopathology perspective, proposes that lack of impulse control is related to earlier childhood problems. While there is little current use of psychoanalysis in diagnosing and treating juvenile delinquents, practitioners use its concepts in describing and evaluating deviant behavior. The second model, behavior modification, follows the general stimulus/response theory of conditioning. Social learning theory extends these concepts past mechanistic reinforcement to informative and motivational modes. The cognitive development approach proposes that the human organism develops in an orderly, sequential manner. Child development is predictive, normative, and positive in a normal environment and is therefore able to accomplish specific developmental tasks. To the extent that developmental needs are not met, youths will encounter problems, rely on peer groups for knowledge, and will tend more toward delinquent acts. Normal adolescents feel the need to confront authority, to move towards independence, and to emulate adult behavior as they perceive it. If adults view this behavior as inappropriate, they may bring the power of the juvenile justice system to bear on the adolescents. A total of 31 references are included.