European Journal of Social Psychology Eur. J. Soc. Psychol. 36, 617–633 (2006) Published online 30 March 2006 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ejsp.305 Modeling collective choice: Decision-making on complex intellective tasks BRYAN L. BONNER, 1 * MICHAEL R. BAUMANN, 2 AUSTIN K. LEHN, 3 DAISY M. PIERCE 3 AND ERIN C. WHEELER 3 1 University of Utah, USA 2 University of Texas, San Antonio, USA 3 Williams College, Massachusetts, USA Abstract Three studies examined group problem-solving on complex intellective tasks. In Study 1, a decision model proposed by Laughlin and Hollingshead (1995) provided the best fit to actual group choices. This study also compared three-person group versus individual performance with time constrained and number of problems unconstrained, with individuals solving non-significantly more problems and groups obtaining significantly superior trials-to-solution scores. In Study 2, one member of each group was given additional information on how to perform the task and member extroversion was measured. Neither factor significantly impacted the decision-making process. In Study 3, task expertise was assessed prior to the group interaction. Results indicate that group members were twice as likely to adopt an option proposed by an expert compared to other group members. Together these studies demonstrate that group problem solving is governed jointly by qualities of the task and qualities of the group members. Copyright # 2006 John Wiley & Sons, Ltd. In everyday life, groups are responsible for making some of the most important decisions and solving some of the most complex problems available in our world. A preference for group as opposed to individual decisions is prevalent in many areas of business, law, public policy, and politics. It follows that the study of group decision-making is of fundamental importance to both social science and to practice. Of particular interest in this area is the question of how groups go about combining the different preferences of group members in generating a group solution. Given that the different individuals in a group may have conflicting perspectives, opinions, and biases, how do groups actually go about generating decisions? What are some of the factors that may make certain individuals more influential in group decisions than others? In this paper we focus on two streams of research to address this question: the general social combination literature, which describes robust patterns of group decision-making without factoring in individuals differences (e.g., Laughlin Received 1 October 2004 Copyright # 2006 John Wiley & Sons, Ltd. Accepted 21 June 2005 *Correspondence to: Bryan L. Bonner, David Eccles School of Business, University of Utah, 1645 E. Campus Drive #106, Salt Lake City, Utah 84112, USA. E-mail: mgtblb@business.utah.edu