How to Improve Decision Making in Small Groups: Effects of Dissent and Training Interventions

Decision-making groups are often biased in favor of shared information
(sharedness bias) and in favor of its members initial preferences (preference
bias). In a group experiment, both biases were analyzed at the group level
(communication of information and preferences) and at the individual level
(evaluation of information) simultaneously. Two interventions were evaluated,
each focusing on one of the two biases and illustrating it with a group exercise.
The interventions enhanced the amount of discussed information and reduced
the preference bias but had no effects on decision quality. Dissent (diversity in
members initial preferences) enhanced the preference bias in information
exchange but reduced both biases in information evaluation and improved
decision quality when no intervention was applied. Decision quality correlated
with individual-level processes but not with group-level processes.