Personality, sexuality, and demographic differences between volunteers and nonvolunteers for a laboratory study of male sexual behavior.

Personality, sexuality, and demographic differences were examined in volunteers and nonvolunteers for a laboratory study of male sexual arousal. Subjects were 108 participants in a questionnaire study entitled "Personality and Sexuality", who were then asked to volunteer for a second study which necessitated watching sexually explicit films, being partially undressed in an experimental chamber, and having penile diameter measured via a strain gauge device. Volunteers for the second study were found to be less guilty, less sexually fearful, more sexually experienced, and older than nonvolunteers. Volunteers also reported a higher incidence of past erectile difficulties and tended to be White or of mixed racial heritage, as opposed to being Oriental. Other personality variables did not discriminate between the two groups. The results indicate that future research in human sexuality using the laboratory analytic method must impose strict limits on generalization from the research data.