UC Santa Barbara

Moral decision-making typically involves trade-offs between moral values and self-interest. While previous research on the psychological mechanisms underlying moral decision-making has primarily focused on what people choose, less is known about how an individual consciously evaluates the choices they make. This sense of having made the right decision is known as subjective confidence. We investigated how subjective confidence is constructed across two moral contexts. In Study 1 (240 U.S. participants from Amazon Mechanical Turk, 81 female), participants made hypothetical decisions between choices with monetary profits for themselves and physical harm for either themselves or another person. In Study 2 (369 U.S. participants from Prolific, 176 female), participants made incentive-compatible decisions between choices with monetary profits for themselves and monetary harm for either themselves or another person. In both studies, each choice was followed by a subjective confidence rating. We used a computational model to obtain a trial-by-trial measure of participant-specific subjective value in decision-making and related this to subjective confidence ratings. Across all types of decisions, confidence was positively associated with the absolute difference in subjective value between the two options. Specific to the moral decision-making context, choices that are typically seen as more blameworthy – i.e., causing more harm to an innocent person to benefit oneself – suppressed the effects of increasing profit on confidence, while amplifying the dampening effect of harm on confidence. These results illustrate some potential cognitive mechanisms underlying subjective confidence in moral decision-making and highlighted both shared and distinct cognitive features relative to non-moral value-based decision-making.