Pooling of unshared information in group decision making: Biased information sampling during discussion.

TLDR

Groups can benefit from pooling partial, biased information to form an unbiased view of alternatives. The study tests whether biased sampling during discussion prevents effective information pooling, favoring shared or preference‑supporting information. Participants read biased candidate descriptions and then discussed them in a simulated caucus. Groups chose the initially preferred candidate over the objectively best one, and discussion reinforced rather than corrected distorted perceptions.

Abstract

Decision-making groups can potentially benefit from pooling members' information, particularly when members individually have partial and biased information but collectively can compose an unbiased characterization of the decision alternatives. The proposed biased sampling model of group discussion, however, suggests that group members often fail to effectively pool their information because discussion tends to be dominated by (a) information that members hold in common before discussion and (b) information that supports members' existent preferences. In a political caucus simulation, group members individually read candidate descriptions that contained partial information biased against the most favorable candidate and then discussed the candidates as a group. Even though groups could have produced unbiased composites of the candidates through discussion, they decided in favor of the candidate initially preferred by a plurality rather than the most favorable candidate. Group members' pre- and postdiscussion recall of candidate attributes indicated that discussion tended to perpetuate, not to correct, members' distorted pictures of the candidates.