To examine the effects of locus of control (the extent to which an individual feels he has control over his own behavior) and cognitive style variables on learning deficits among mentally handicapped children, 80 mentally retarded boys (IQ 50 to 83, age 160 to 196 months) were administered a battery of tests. Analyses of student performance indicated that subjects with internal locus of control and analytic cognitive style gave more correct responses in the initial acquisitions phase than did externally controlled and global children. No difference was observed in the final acquisition block; however, when composite correct responses were analyzed, the analytic children were found superior to global children. Indiscriminate use of verbal support appeared to depress retardates' performance on a concept learning task. Implications concerning potency of social reinforcers and reevaluation of performance deficit in terms of non-intellective factors were noted. (RD)