Human Relations, Ahead of Print.
Managing and harmonizing intragroup relationships are critical for effective team leadership. Though previous studies have confirmed how team leaders promote positive ties in work teams, it remains unclear whether or how they can benefit the team by helping to reduce negative ties. How can team leaders simultaneously encourage positive ties and prevent negative ties to elevate team effectiveness? Drawing on social ledger theory and leader humility, we propose that humble leaders can improve team performance and viability through first influencing intragroup positive and negative tie density and thereby promoting team-helping norms. In Study 1 (70 professional work teams), we find that leader humility is associated with elevated team-helping norms and team effectiveness through lower levels of hindrance density rather than promoting friendship density. In Study 2 (50 retail teams), we replicate Study 1 but additionally control for transformational leadership. The results suggest that the positive association between leader humility and friendship density becomes insignificant after transformational leadership is considered, whereas the association between leader humility and hindrance density remains significant. This research contributes to the literature by illuminating how leadership is associated with team social networks and highlights practical implications for managing professional teams and developing team leadership.