Using Quay's typology, three equal groups (n=12) of adolescent psychopathic, neurotic, and subcultural delinquent males and a matched nondelinquent control group were individually administered Kohlberg's structured moral dilemmas, two Piagetian tasks of cognitive development (pendulum and balance), and an adaption of Flavell's role-taking task. Psychopathic delinquents were more immature in level of moral development than all other groups which did not differ from one another. Psychopathic delinquents were significantly more concrete in their thinking on cognitive tasks than all other groups who exhibited signs of early formal operational thinking. Psychopathic and to a lesser extent neurotic delinquents were deficient in role taking compared with controls and subculturals who did not differ from one another. The findings provide further evidence against viewing delinquency as a unitary syndrome of deviance. (Author)