Normative and Informational Effects of Group Interaction

Sources of group-induced shift on choice dilemma items were examined by comparing the typical discussion treatment with normative and informational treatments. Control condition groups responded to three risky choice dilemma items without prior treatment. Social comparison condition groups responded after being exposed to the percentage distribution of initial responses by control subjects. Relevant arguments condition groups responded after discussing the items without pretest and without awareness of the probability scale. Both experimental treatments produced significant effects when compared to control responses; These and other findings are interpreted as supportive of a two-process explanation of group-induced shift and as contrary to explanations of group shift based on group decision models.