Team Composition, Cognition, and Effectiveness: Examining Mental Model Similarity and Accuracy Christian J. Resick Drexel University Marcus W. Dickson Wayne State University Jacqueline K. Mitchelson Auburn University Leslie K. Allison and Malissa A. Clark Wayne State University This study examined the relationships between team cognitive ability and personality composition in relation to the similarity (MM-similarity) and accuracy (MM-accuracy) of team task-focused mental models. The relationships between MM-accuracy and MM-similarity with multiple indicators of team effectiveness were also examined. Sixty-seven three-person teams performed a simulated search and capture task. Results indicate that the team mean-level of cognitive ability was positively related to both MM-accuracy and MM-similarity, and the team mean-level of team agreeableness was positively related to MM-similarity. In turn, MM-accuracy was positively related to perceived coordination processes and goal accomplishment, but not team viability. In contrast, MM-similarity was positively related to team viability, but not goal accom- plishment or perceived coordination processes. Implications of the findings for under- standing factors that facilitate the emergence of task-focused mental models in teams with a limited life span or during the early stages of team development are discussed, along with the implications of team mental models for team success. Keywords: shared cognition, team composition, team mental models Working in teams is fundamentally different than working alone because of the interdepen- dencies that exist among members (Guzzo & Dickson, 1996; Salas, Dickinson, Converse, & Tannenbaum, 1992). Therefore, team members must devote attention to completing the task at hand as well as to coordinating their efforts with other members (Stevens & Campion, 1994). Team mental models, representing shared struc- tural knowledge, are a form of cognitive simi- larity believed to play a particularly important role in enabling a team to perform effectively as a unit (Cannon-Bowers & Salas, 1990; Kraiger & Wenzel, 1997; Rentsch, Small, & Hanges, 2008). The similarity among (MM-similarity) and the accuracy of (MM-accuracy) team mem- bers’ mental models have been found to be related to effective processes and performance outcomes (e.g., Marks, Zaccaro, & Mathieu, 2000; Smith-Jentsch, Mathieu, & Kraiger, 2005). Ad hoc teams, where individuals are brought together to work on a specific assignment and then disband once the assignment is complete, are a form of team that is commonly used throughout business and industry (Devine, Clayton, Philips, Dunford, & Melner, 1999; Sundstrom, McIntyre, Halfhill, & Richards, 2000). For example, because of the need for diverse and specific types of expertise, consult- ing teams often bring together technical special- ists to complete a consulting assignment and then disband. Ad hoc teams are unique in that members often have limited knowledge of their teammate’s capabilities and work styles, yet they must quickly form a shared understanding of their goals, tasks, performance environment, and strategies to integrate their efforts and per- form effectively. Therefore, the ability to Christian J. Resick, Drexel University; Marcus W. Dick- son, Wayne State University; Jacqueline K. Mitchelson, Auburn University; Leslie K. Allison, Wayne State Univer- sity; and Malissa A. Clark, Wayne State University. Correspondence concerning this article should be ad- dressed to Christian J. Resick, Management Department, LeBow College of Business, Drexel University, Philadel- phia, PA 19104. E-mail: cresick@drexel.edu Group Dynamics: Theory, Research, and Practice © 2010 American Psychological Association 2010, Vol. 14, No. 2, 174 –191 1089-2699/10/$12.00 DOI: 10.1037/a0018444 174