Abstract

A meta-analysis was conducted on the accuracy of predictions of various objective outcomes in the areas of social and clinical psychology from short observations of expressive behavior (under 5 min). The overall effect size (/) for the accuracy of predictions for 38 different results was.39. Studies using longer periods of behavioral observation did not yield greater predictive accuracy; predictions based on observations under Vi min in length did not differ significantly from predic-tions based on 4- and 5-min observations. The type of behavioral channel (such as the face, speech, the body, tone of voice) on which the ratings were based was not related to the accuracy of predic-tions. Accuracy did not vary significantly between behaviors manipulated in a laboratory and more naturally occurring behavior. Last, effect sizes did not differ significantly for predictions in the areas of clinical psychology, social psychology, and the accuracy of detecting deception. The way in which people move, talk, and gesture—their fa-cial expressions, posture, and speech—all contribute to the for-mation of impressions about them. Many of the judgments we make about others in our everyday lives are based on cues from these expressive behaviors. Gordon Allport (1937) believed that