Personality Moderators of the Experimenter Expectancy Effect: A Reexamination of Five Hypotheses
Researchers examining personality moderators of experimenter expectancy effects have focused on five hypotheses. Experimenters with stronger interpersonal control orientations, more positively evaluated interpersonal interaction styles, and greater ability to encode nonverbal messages are believed to be more likely to produce expectancy bias. Subjects with greater need for social approval and greater nonverbal decoding ability are believed to be more susceptible to bias. In this study each experimenter administered a photo-rating task under positive or negative expectancies to four subjects, each of whom also interacted with three other experimenters. All five personality moderator hypotheses were tested. Support was found only for the experimenter control orientation and subject need for social approval hypotheses. There was also evidence for a boomerang effect—subjects low in need for social approval gave ratings opposite to the experimenter's outcome expectancy. Finally, effects appeared stronger when positive expectancies were communicated than when expectancies were negative.