Social validation in group decision-making: Differential effects on the decisional impact of preference-consistent and preference-inconsistent information

Shared information has a stronger impact on group decisions than unshared information. A prominent explanation for this phenomenon is that shared information can be socially validated during group discussion and, hence, is perceived as more accurate and relevant than unshared information. In the present study we argue that this explanation only holds for preference-inconsistent information (i.e., information contradicting the group members’ initial preferences) but not for preference-consistent information. In Experiments 1 and 2 participants studied the protocol of a fictitious group discussion. In this protocol, we manipulated which types of information were socially validated. As predicted, social validation increased the decisional impact of preference-inconsistent but not preference-consistent information. In both experiments the effect of social validation was mediated by the perceived quality of information. Experiment 3 replicated the results of the first two experiments in an interactive setting in which two confederates discussed a decision case face-to-face with one participant.