Today's greatest challenges from climate change to technological distruptions are inherently global in nature and cannot be solved by single nations acting alone. Yet, both system-level and public support for global cooperation are in decline. Social identity approaches suggest that broader self-categorisation, such as seeing all humanity as one ingroup, can foster cooperation. Yet, global identification tends to remain low and difficult to cultivate. Interdependence theory, that has long been theorized, offers an alternative pathway: cooperation arises when goal attainments mutually linked with others. While well established in small groups, little is known how it functions at large and abstract scales.


We map how perceived interdependence varies across group scopes, from work teams to the globe, and how it relates to prosociality. In a between-subjects study (N = 1000), participants were randomly assigned to one group level (work team, city, nation, or world). They reported perceived interdependence and group-related cognitions (e.g., identity), then completed outcomes such as group prosociality, a resource allocation task pitting a close friend against an ingroup member, and policy support for a proposed global tax addressing shared challenges.


Interdependence perceptions did not decline monotonically with group scale, unlike social identity. Importantly, global-level interdependence was non-trivial and not reducible to global identity. Across levels, it consistently predicted prosociality and generosity, even when identity was controlled. Furthermore, its link to global tax support was stronger than of identity. These findings suggest that interdependence, above and beyond identity, can serve as a robust psychological basis for cooperation even at the global level.


We conclude with implications for communication and policy. Making mutual dependence salient (in the context of climate, economy, or technological domains) could be more effective than identity appeals for mobilizing global cooperation. By framing interdependence, practitioners and policymakers can foster the prosocial orientations needed to strengthen global governance.