Proceedings of the Annual Meeting of the Cognitive Science Society

Understanding human morality is of major interest across the cognitive and behavioral sciences. Empirical approaches often focus on two theories from moral philosophy — consequentialism and deontology —, explaining moral cognition by appealing to either calculation of consequences, adherence to rules, or both. By contrast, a third influential philosophical tradition — contractualism — has received little empirical investigation. According to contractualism, ethics is a matter of forming, adhering to, and enforcing (hypothetical) agreements. Drawing upon virtual bargaining — a recent psychological proposal that models social interactions in contractualist terms — we investigate moral contractualism in five preregistered online experiments (n = 3,636). We find that characteristically contractualist concerns (e.g., agreement, consent, mutual interests) heavily shape incentivized decisions in a new experimental game designed to split apart contractualism from consequentialism and deontology. Moreover, they influence moral judgments in three distinct settings. Contractualist reasoning may play a central role in human morality.