Mentally retarded adults (N=180) were asked 30 yes/no questions, to determine if their acquiescence is explained by indiscriminant yea-saying in response to the yes/no question format or due to subjects submitting to the influence of the interviewer. After selected questions, the interviewer either nodded his head "yes" or shook his head "no" or did neither, providing a cue to the subjects as to what response the interviewer desired. As a second experimental manipulation, subjects were interviewed by either a familiar person or someone they did not know. Results indicated that subjects were significantly influenced by the interviewers' head-nodding, thereby supporting the hypothesis that acquiescent responding among the mentally retarded is a form of maximizing reinforcement by submitting to others. Familiarity with the interviewer did not affect subjects' responses. Includes five references. (Author/JDD)