To check the validity of individualism-collectivism theory in understanding conflict behaviors within a culture, two experiments were run using vignette method. In Experiment 1, children (half Individualists and half Collectivists) were asked to resolve a conflict in which their wish was incompatible with that of another. The other belonged to various in-groups or out-groups. The Collectivists showed far greater discrimination between in-group and out-group members than did the Individualists. In Experiment 2, the same children were asked to play the role of an allocator who, having contributed more to a task, was to divide the reward between him- or herself and the co-worker. Two independent variables manipulated were the co-worker's membership (in-group/out-group) and the likelihood of future interaction with the co-worker (high/low). Individualists favored an equitable division over an equal division regardless of the experimental manipulations. The Collectivists, however, favored the equitable division only in the out-group-low future interaction condition. In other conditions, they favored equal division. The results provide strong support to the theory of collectivism-individualism, originally developed to understand cross-cultural differences in social acts.