Cognitive reflection predicts utilitarian behavior in the monetary moral dilemma after 17 months

The dual-process model of moral judgment proposes that utilitarian choices arise from reflective processes that can override intuitive, rule-based responses. Yet most supporting evidence relies on sacrificial dilemmas with limited ecological validity and problematic associations with antisocial traits. This preregistered study investigated whether individual differences in reflection predict utilitarian behavior in an incentivized setting. At Time 1, 1,200 U.S. participants completed performance-based measures of reflection, reasoning ability, dispositional thinking styles, and the Oxford Utilitarianism Scale (OUS). Seventeen months later, 321 participants completed a monetary moral dilemma with real economic consequences and reported their moral justifications. Initial measures of reflection, including the Cognitive Performance Test, Raven’s matrices, and open-minded thinking, predicted utilitarian behavior. Neither impartial beneficence nor instrumental harm subscales of the OUS predicted utilitarian behavior. Exploratory analyses showed that religiosity moderated the reflection–utilitarian behavior association: reflection predicted utilitarian behavior more strongly among non-believers than believers. These findings highlight reflection as a predictor of utilitarian behavior across time, question the validity of self-report utilitarianism scales such as the OUS, and underscore the importance of religious belief in cognitive reflection when examining individual differences in moral behavior.