Disentangling Normative and Informational Influence in Group Decision Making
- Author(s): Garcia, Robert Jaffe
- Advisor(s): Scurich, Nicholas
- et al.
Although extensive social psychological research has examined conformity for individualized behaviors, no laboratory research has experimentally manipulated conformity in the context of group decisions. Normative conformity is motivated by the desire for social acceptance while informational conformity entails looking to others for correct answers. Using the applied context of a jury deliberation, the present studies aimed to disentangle the relative effects of normative and informational conformity by comparing participants’ votes and ratings of evidence convincingness before and after exposure to a confederate group’s opinions during a poll. Private polls were intended to shield jurors from normative influence, while public polls invited conformity via both normative and informational influence. Results showed disagreement with the group majority during the first poll was a consistently strong predictor of vote switching, but no significant differences emerged in vote switching between public and private deliberation. Changes in beliefs about the strength of the evidence against the defendant partially mediated the effect of a disagreeing majority on vote switching. For participants who initially voted guilty, changes in beliefs drove a greater proportion of conformist vote switching in public deliberations than in private deliberations. This finding suggests that people may weigh public comments in group decisions more heavily or that the pressure to conform in public deliberation may increase susceptibility to belief change. More generally, it also suggests that normative pressure may sometimes fuel informational influence, and that the two constructs may be more linked than previously conceptualized. Implications are discussed for extant research on the intersection between conformity and group decision making and for jury protocol.