Introduction
The publication in 1968 of Rosenthal and Jacobson's Pygmalion in the Classroom catalyzed phenomenal interest in the apparent power of interpersonal expectations but also in the possible communication processes that might be responsible. The question seemed to be how such expectations could be “sent” by a teacher (or experimenter, coach, therapist, etc.) and also “received” by a pupil (or research subject, student, patient, etc.). Although verbal cues could not be ignored, attention quickly focused on nonverbal communication as the most promising vehicle for the unintentional, implicit transfer of interpersonal expectations.
The nonverbal channels thought most likely to play a role included tone of voice, facial expressions, eye contact, hesitations, gestures, touch, and proxemics. One reason the nonverbal channels were quickly implicated in the expectancy process was that, 5 years prior to the publication of Pygmalion, a landmark experiment showed that expectation could be communicated between people and rats (Rosenthal & Fode, 1963). Even with the human-to-human communication of expectation in Pygmalion - and in the hundreds of replications that followed (Rosenthal & Harris, 1985; Rosenthal & Rubin, 1980) - subtle nonverbal channels seemed to offer more promising explanations than explicit verbal cues. Just as it seemed unlikely that experimenters could affect the behavior of rats by telling them they were “maze dull,” it seemed improbable that therapists would tell some patients that they were unlikely to respond to treatment, that coaches would tell certain campers they were unlikely to learn to swim, and so on. The transmission of expectations seemed certain to occur via nonverbal communication.