Theoretical assumptions from Rotter's (1954, 1966) social learning theory are used to examine evidence for the antecedents of individual differences in locus of control of reinforcement. Children with generalized internal as opposed to external control expectancies report less stress early in their lives and have parents who treat them more consistently, grant them greater autonomy, and provide them with a warn, supportive relationship. However, most research on this topic is characterized by self-report, cross-sectional, and correlational methodologies that are indirect and do not allow for assessment of cause and effect. As a result, little is known about the development of individual differences in locus of control. We suggest the use of observational and longitudinal methodologies, an evaluation of possible bidirectionality of influence between parents and children, and a return to Rotter's social learning theory for definition and guidance.