This study investigated whether cognitions and behavior in an asymmetric social dilemma can be predicted by national culture. Results indicated that, as predicted, groups of decision makers from Japan--a collectivist, hierarchical culture-were more cooperative, expected others to be more cooperative, and were more likely to adopt an equal allocation distribution rule to resolve the dilemma than were groups of decision makers from the United States-an individualist, egalitarian culture. An opportunity for communication had a greater impact on expectations of others' behavior in groups of U.S. decision makers than in groups of Japanese decision makers.