Investigated in two studies involving 52 profoundly retarded Ss (8-29 years old) were a parameter descriptive of the subject (sex) and the effectiveness of a modeling technique to evoke a response. The major finding of the first investigation in which there were two sessions was that exposure of Ss to a live model produced a significant increase in modeling behavior, while there were no sex differences found. Results of the second investigation involving only one exposure to the model indicated that exposure of Ss to a model produced no significant change in behavior. (SBH)