Abstract: Subgroups within a team can result in differentiation, discord, and even the dissolution of the team. However, previous research has neglected to acknowledge the pivotal role of the team leader in directly coordinating activities among subgroups and has failed to conduct a thorough analysis of the tripartite relationship involving the team leader, subgroups, and the entire team. This study aims to integrate a social network perspective and introduce a novel concept termed “team leaders' simmelian brokerage”. In this concept, team leaders act as intermediaries between two or more subgroups. We suggest that it may help address different conflicts among subgroups and subsequently facilitating team cooperation. Firstly, employing a categorization of social network content, this study classifies simmelian brokerage into instrumental simmelian brokerage and expressive simmelian brokerage. Instrumental simmelian brokerage pertains to the mediation between distinct subgroups within instrumental networks, which are primarily work- or task-oriented networks, such as workflow or advice networks. On the other hand, expressive simmelian brokerage concerns the mediation between different subgroups within expressive networks, which are predominantly friendship or support-related networks. By integrating social network content and structure, this approach enables a more detailed examination of the influence of team leaders' simmelian brokerage of different network content, thereby providing a theoretical foundation for understanding how team leaders' simmelian brokerage promotes teamwork. Secondly, drawing from “The Changing Others' Relationships Framework”, this study explores the mechanisms through which simmelian brokerage in different network content affects subgroup conflicts and subsequent team cooperation. As simmelian brokers operating in various social networks, team leaders can mitigate conflicts between two or more subgroups to a certain extent through their intermediary actions, thereby fostering team cooperation. Specifically, when team leaders occupy the role of instrumental simmelian brokerage in workflow networks, they possess significant advantages in terms of acquiring comprehensive and high-quality job-related information. Armed with this informational and resource advantage, team leaders can effectively coordinate tasks among multiple subgroups towards the team's goals, thereby reducing task-related conflicts and ultimately enhancing team cooperation. When team leaders act as expressive simmelian brokerage in friendship networks, they can alleviate relationship conflicts among subgroups through informal relationships. For instance, they can employ diverse measures to minimize the transmission and proliferation of negative emotional information among subgroups, and adeptly mediate conflicts as soon as they arise. All of these actions can have a positive impact on team cooperation. Thirdly, we identify tertius iungens orientation and political skills as crucial boundary conditions for the effects of simmelian brokerage on subgroup conflicts and subsequent team cooperation. Specifically, when team leaders exhibit a high tertius iungens orientation, they are more inclined to employ multiple strategies to facilitate information exchange and foster emotional connections among several subgroups. Furthermore, when team leaders possess high political skills, they are better equipped to leverage their simmelian brokerage positions and opportunities to exert influence. Consequently, these team leaders can assist the team in mitigating task and relationship conflicts among subgroups, thereby promoting team cooperation. This study not only advances the understanding of subgroup dynamics but also offers practical guidance for subgroup management. Theoretically, we develop a conceptual framework for the tripartite relationship among team leaders, subgroups, and the entire team by drawing on a social network perspective, thereby providing a nuanced understanding of the processes involving simmelian brokerage, subgroup conflicts, and team cooperation. From a practical standpoint, these findings can aid team managers in integrating different aspects of social networks (instrumental and expressive networks) within the team and effectively utilizing their key positions (e.g., as simmelian brokers between subgroups) to manage both subgroups and the entire team.

Key words: team leader,  Simmelian brokerage,  subgroup, team cooperation