Morality is Supreme: The Roles of Morality, Fairness and Group Identity in the Ultimatum Paradigm.

Purpose: A large number of decision-making need to be carried out in the context of social interactions. Previous studies have demonstrated the impact of fairness perception, moral judgment, and group identity on decision-making. However, there is no clear conclusion as to how the effect of these factors existing simultaneously on decision-making and the extent to which these factors play a role. Methods: We manipulated the moral quality of proposers to explore the issue of whether morality has an impact on fairness perception and manipulated the moral quality of proposer and responder simultaneously forming group identity to explore whether group identity has an impact on the effect of morality on fairness in decision-making. Results: Participants displayed a higher acceptance rates for positive moral proposers than the negative moral proposers regardless of the fairness of the allocation of money (Experiment 1) and group identity (Experiment 2). However, the effect of group identity was working, though it partially supported the In-group Preference (Experiment 1 and Experiment 2 combined analysis). We hold that the group identity was influenced by morality. Conclusion: When making an economic decision, morality has the supreme influence on individuals.