Summary
It was proposed that a child's locus of control may help to determine when self-reinforcement or external reinforcement is superior in motivating academic task performance. One hundred fifty-three fourth and fifth grade boys selected on the Intellectual Achievement Responsibility Questionnaire (IAR) as having either an internal or external locus of control in academic tasks were assigned to self-reinforcement or external reinforcement conditions. External reinforcement led to greater task output than selfreinforcement. However, when locus of control was defined by use of both IAR subscales rather than by the total score, externals performed best under conditions of external reinforcement, as predicted, while internals performed equally well under both conditions.