Mine Vs. Our money: An ultimatum game experiment with groups

Behavioural economics has emphasised the study of individual decision-mak-ing. Although in real life decisions are often made by groups rather than individuals, group behaviour has received less attention. Nevertheless, this literature suggests that groups behave more rationally and selfishly than individuals in experiments with social considerations, aligning more closely to the homo economicus model. However, these experiments have not considered the possible impact of a prior task, a factor that could foster selfishness. This study aims to address how behaviour may differ between groups and individuals in an experiment based on the ultimatum game. It incorporates a pre-task that introduces a merit component, setting it apart from earlier research. Contrary to previous evidence, in this experiment groups do not behave more selfishly than individuals. Groups tend to reject higher offers and there are no significant differences in the offers made. There are also no differences between groups and individuals in the offers made to the best-performing participants in the task. The role of social norms, such as fairness, could help explain these results.