The effects of social exclusion on distributive fairness judgements and cooperative behaviour

In this article, we investigate how being socially excluded (vs. included) affects people's distributive fairness judgements and their willingness to cooperate with others in subsequent interactions. For this purpose, we conducted three experiments in which we assessed individual differences in having experienced being socially excluded (Experiment 1, N = 164), and manipulated social exclusion (Experiment 2, N = 120; Experiment 3, N = 492). We studied how this impacted fairness judgements of three different outcome distributions (disadvantageous inequality, advantageous inequality, and equality) both within-participants (Experiments 1 and 2) and between-participants (Experiment 3). To assess behavioural consequences, we then also assessed participants' cooperation in a social dilemma game. Across the three experiments, we consistently found that social exclusion impacted fairness judgements. Compared to inclusion, excluded participants judged disadvantageous inequality as more unfair and advantageous inequality as less unfair. Moreover, compared to socially included participants, socially excluded participants were more willing to cooperate after experiencing advantageous rather than disadvantageous inequality, and feelings of acceptance served as a mediator in these associations.