Characteristics of Volunteers and Nonvolunteers for a Sleep and Hypnotic Experiment

Thirty-seven student nurses, representing six schools of nursing in New England, were administered a series of objective tests while on affiliation at a public psychiatric hospital. In addition, all subjects were asked to volunteer for a sleep and hypnotic experiment that required spending two nights in a research laboratory. Although volunteers and nonvolunteers showed no difference in intelligence or ego-strength, the volunteers performed less effectively on academic tasks. In addition, volunteers scored lower on the EPPS autonomy and dominance subscales. While volunteers did not differ from nonvolunteers in their own M-C S.D. need approval scores, they were rated by their instructors as being more conforming and defensive, and were more likely to indicate as best friends other students scoring high in need approval.