The purpose of this study was to investigate whether there are differences between males and females on locus of control, if experimental instructions differentially affect the performance of internals as opposed to externals, and if locus of control differentially influences performance on distinct types of aptitude tests. The Children's Nowicki-Strickland instrument was given to 144 children to determine their scores on locus of control. Following completion of the scale, subjects were divided into one of three performance feedback conditions: success, failure, and no feedback. Results indicated that internals scored significantly higher on verbal problem solving measures than did externals. There was a connection between locus of control and performance on a verbal inductive reasoning component of an aptitude test battery, but not on a spatial inductive reasoning test. No sex differences were reported, and feedback condition did not interact with locus of control. (Author/JAZ)