Article Abstract
Sargis, E. G., & Larson, J. R., Jr.  (2002).  Information Centrality and Member Participation During Group Decision Making.  Group Processes and Intergroup Relations, 5, 331-345.

Abstract.   This study examined whether participation during group decision-making discussions is affected by the degree to which member hold predominately shared versus predominantly unshared decision-relevant information.  Altogether, 115 three-person, same-sex groups completed a decision-making task in which a majority of the information held by a randomly selected target member either was also held by other members of the group (shared information) or was held by the target member alone (unshared information).   It was found that in comparison to target members who held mostly shared information, targets who held only unshared information claimed fewer speaking turns and contributed fewer information-based comments during discussion.  Further, holding unshared information appeared to depress participation to a greater extent than holding shared information facilitated participation, relative to a standard of equal participation across all group members.  These participation effects subsequently influenced target members' agreement with their group's eventual decision, with lower participation resulting in lower agreement.  Thus, in addition to the negative consequences that unequally distributed information can have for the group as a whole, the present findings highlight a parallel set of negative consequences that can exist for individual members of the group.