Abstract
This chapter critically interrogates the psychological dynamics of ostracism and their implications for social identity, intergroup behavior, and contemporary leadership practices. Drawing on the social identity framework and related perspectives, it explores whether exclusion from social groups leads to defensive discriminatory behavior, particularly among men seeking to reassert belonging and affirm group identity. However, findings from a series of four empirical studies challenge prevailing assumptions, revealing a more nuanced and context-sensitive reality. Employing variations in the Cyberball paradigm to simulate social inclusion and exclusion, the studies consistently found that ostracized men did not exhibit increased discrimination. In several instances, participants demonstrated out-group favoritism, particularly toward women—subverting common predictions rooted in social identity threat theory. These results suggest that exclusion may not always trigger inward-turning tribalism, but can instead evoke prosocial, bridge-building behaviors depending on the social context, perceived norms, and individual agency. By unpacking these patterns, the chapter offers powerful implications for leadership within organizations and political institutions. Leaders, often tasked with managing diverse teams under conditions of stress, must understand how experiences of inclusion or marginalization shape interpersonal dynamics and group cohesion. The research highlights the importance of fostering inclusive environments, training leaders to recognize non-obvious responses to exclusion, and cultivating cultures where belonging is addressed systemically rather than assumed. In aligning with the Handbook’s broader themes—particularly the intersections of leadership, politics, and identity—the chapter reframes ostracism not merely as a psychological stressor but as a leadership concern with far-reaching consequences. It challenges leaders to move beyond traditional assumptions about power, bias, and group behavior, advocating for a more empathetic, evidence-informed approach to social inclusion and organizational decision-making.