This paper examines the conceptual and empirical relationships differentially associated with antisocial behavior and undercontrol, two concepts that frequently are confused. The personality characteristics conceptually associated with antisocial behavior were specified by seven psychologists using the California Child Q-sort (CCQ) to describe independently a prototypically antisocial adolescent. Next, CCQ descriptions of each adolescent in a longitudinal study of ego and cognitive development of 3-, 4-, 5-, 7-, 11-, and 14-year-olds were correlated with the prototype. The congruence between an actual CCQ description and the prototype was the index of antisocial personality. Undercontrol was operationalized similarly. Indices of antisocial personality and of undercontrol then were related to indices of adolescent drug usage, self-concept, and parental child-rearing practices. Numerous external correlates distinguished between antisocial personality and undercontrol. Antisocial personality, but not undercontrol, predicted drug usage at age 14 in both sexes. The value systems of antisocial males reflect aspirations for wariness and uninvolvement. Parental child-rearing values foretold antisocial behavior and undercontrol more frequently in girls than in boys. (Author/RH)