The construct of self-control was explored as a correlate of the Internalizing-Externalizing symptom dimension.Ss were 11-13-year-old boys including 26 Internalizers with neurotic-like behavior problems, 40 Externalizers with acting-out behavior problems, and 26 normals. Each group was equally divided on the basis of social-class status. Results of measures on delay of gratification, reflection-impuisivity, and foresight and planning indicated that the normals exhibited the greatest degree of self-control and the Externalizers the least, while the Internalizes maintained an intermediate position. Consistent social-class differences were not found, but the factor of social class did heighten the differences within the Internalizers and Externalizers.