Beyond ingroup favoritism: Investigating cross-national social preferences across 25 nations

Global challenges such as climate change require cooperation across nations-not only among governments but also among individuals. In an incentivized cross-national study with 6,182 participants from 25 nations, we assessed individuals' prosociality as a core predictor of cooperation toward people from 25 different nations, yielding 625 distinct national dyads. Integrating theoretical approaches, this study examines how both individual perceptions and contextual factors-unique to each national dyad-shape intergroup prosociality. Our findings reveal significant variation in cross-national prosociality beyond ingroup favoritism. Prosociality increased with greater cultural and national stereotype similarity. Individuals from nations with reliable institutions exhibited greater prosociality, and those from wealthier nations were particularly prosocial toward individuals from less wealthy nations. In contrast, prosociality decreased with increasing perceived and actual militarized conflict between nations. These results highlight the importance of incorporating social perceptions and contextual factors that reflect bilateral relationships between nations in theories of global prosociality.