Overt expression of experimenter expectancies,interaction with subject expectancies,and performance on a psychomotor task

Subsequent to success or failure experience, 48 subjects attempted a psychomotor task in order to escape or avoid an aversive stimulus (tone). Their attempts at solving the task over 24 trials were made in the presence of subject-experimenters each of whom had expectancies instilled regarding the solution to the task. The job of the subject-experimenters was to “offer information” on every third trials as the subjects attempted to solve the task. It was hypothesized that the expectancies of the subject-experimenters would be communicated to the subjects via periodic comments, that these expectancies would differentially affect the subjects' performance on the task, and that prior experience on a similar task would differentially affect subjects' performances on the task. The results demonstrated that the expectancies instilled in the subject-experimenters were communicated and influenced the performances of subjects as predicted. It appears that consistency with respect to the expectancies communicated played a major role in producing significant effects. Prior experience failed to produce significant differences on task performance, a finding conflicting with that of D.S. Hiroto (Journal of Experimental Psychology, 1974, 102, 187–193). The results are discussed from the perspective of using the overt, explicit communication of expectancies as a means for exploring the illusive phenomenon of the experimenter expectancy effect.