[Stereotype-based expectancy and social judgment: rethinking from a Bayesian perspective].
To examine effect of prior stereotypical expectancy on social judgment from a Bayesian perspective, undergraduate subjects (N = 204) were asked to infer a target person's attitude toward an atomic power problem. Half of them were told in advance that he was a member of Liberal Democratic Party (pro-expectancy condition), and the other half were told that he was a member of Japanese Socialist Party (con-expectancy condition). Then subjects were given a series of his previous relevant utterances, which had either high or low diagnostic values for the inference of his attitude. "Labeling effect" occurred. That is, despite being given identical utterances, subjects given L.D.P. label estimated the target's attitude to be more favorable toward the atomic power than subjects given J.S.P. label. This effect emerged mainly when subjects were given low diagnostic utterances. Subjects given high diagnostic utterances inadequately underused the base-rate information (prior expectancy) compared with the Bayesian normative value. Utterances congruent with prior expectancy were better recalled than utterances incongruent with prior expectancy.
D000328:Adult; D001290:Attitude; D001499:Bayes Theorem; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D011057:Politics; D012718:Set, Psychology; D012938:Social Perception; D013240:Stereotyping