Covert communication in classrooms, clinics, courtrooms, and cubicles.

Interpersonal expectancy effects refer to the phenomena whereby one person's expectation for another person's behavior comes to serve as a self-fulfilling prophecy. The author examines the history and diversity of this area of inquiry, showing that the expectations of psychological researchers, classroom teachers, judges in the courtroom, business executives, and health care providers can unintentionally affect the responses of their research participants, pupils, jurors, employees, and patients. Using meta-analytic procedures, the author examines (a) moderator variables associated with the magnitude of interpersonal expectancy effects and (b) mediator variables implicated in the communication of interpersonal expectations. The author considers the social importance of the magnitudes of the obtained effects and points out research still needed to clarify issues in the mediation of these effects.