Competing Ideals of Fairness Underlie Wealth Inequality

Wealth inequality often leads to heated debates about resource distribution. An important challenge in addressing polarisation and economic disparities therefore lies in formalising the diversity of individual perspectives regarding what constitutes a fair distribution of resources. We tackle this issue by simulating wealth inequality through the allocation of bonus endowments to participants in both Dictator Game (DG) and Ultimatum Game (UG) settings and capturing distributive decisions. By integrating a computational model, we further quantify individual differences in the interplay between financial self-interest and competing pro-social motivations that emerge in the context of pre-existing wealth inequity. Our behavioural results show that, on average, wealth influences distributive preferences across allocations and proposals, yet existing inequality elicits non-uniform fairness concerns among individuals. Using a hierarchical clustering approach, we objectively categorise participants' behaviour, offering a systematic framework that elucidates four distinct decision strategies: ‘Pro-Self’, ‘Table Egalitarianism’, ‘Total Egalitarianism’, and ‘Moral Opportunism’. A relatively balanced distribution of strategies is observed during allocations, whereas Table Egalitarianism prevails in strategic proposals, highlighting the significant influence of strategic considerations on chosen decision strategy. Furthermore, we demonstrate an association between strategies between decision contexts. Our findings thus contribute a principled framework to formalise the individualised nature of distributive preferences, revealing that, with respect to both altruistic allocations and strategic proposals, competing ideals of fairness underlie the issue of resource distribution under wealth inequality.