The construct of locus of control of reinforcement has generated thousands of studies since its introduction as a psychological concept by Julian Rotter (1966). Although evidence indicates its importance for a wide range of outcomes, comparatively little research has been directed toward identification of potential developmental antecedents of internal/external expectancies. A previous review of antecedent findings (Carton and Nowicki, 1994) called for more research to be completed, particularly using observational and/or longitudinal methodologies. The current paper summarizes and evaluates antecedent research published in the intervening years since Carton and Nowicki's review. Results largely were consistent with expectations based on Rotter's social learning theory, although there is still a need for researchers to use observational, rather than self-report methodologies, and to include data from non-western cultures.