Abstract: The concept of team faultlines serves as an important indicator of explaining subgroup interaction and team effectiveness. However, the mechanism of how team faultlines influence team performance needs to be explained from a more comprehensive theoretical perspective. In this paper, by integrating the optimal distinctiveness theory and the network structure perspective, we establish a theoretical model to explore how team faultlines influence team operation performance by changing the internal interaction structure of the team. Based on questionnaire data of 4,022 employees from 165 work teams and objective operation performance data, the results show that team faultlines has an inverted U-shaped effect on team collaboration network density. Team collaboration network density plays a nonlinear mediating role between team faultlines and team operation performance. The process mentioned above is strengthened by leader brokerage. This study provides a novel theoretical perspective for understanding the key effects of team faultlines, which clarifies the process mechanism between team faultlines and operation performance, and then provides practical implications for firms to manage heterogeneous teams.

Key words: team faultlines, operation performance, collaboration network density, leader brokerage