Intuitive deontology? : a systematic review and multivariate, multilevel meta-analysis of experimental studies on the psychological drivers of moral judgements

Abstract

Humans often face moral dilemmas posing a conflict between two motives: deontology (rule-following, e.g., “thou shalt not kill”) and utilitarianism (greater-good-maximization, e.g., sacrificing one for many). A long-standing debate concerns the influence of cognitive processing on moral judgments in such dilemmas. One popular dual process account suggests that intuition favors “deontological” judgments, whereas “utilitarian” judgments require more reflection. We conducted a comprehensive multilevel, multivariate meta-analysis to assess the cumulative evidence favoring intuitive deontology, its heterogeneity within and across studies, and its robustness to bias. Following established standards, our search for published and gray literature identified 731 unique effects nested in 139 studies from 80 reports meeting our eligibility criteria. Overall, we found a significant but small effect favoring intuitive deontology (OR = 1.18, 95% CI [1.10, 1.26]; p < .0001). We also observed substantial effect heterogeneity stemming from differences within and between studies. Results were robust to outliers, and we found no consistent indications of publication bias. Our preregistered exploration of various moderators resulted in significant explanation of the residual variance by manipulation and dilemma type, with the highest effects of intuitive deontology found for studies using foreign language or induction manipulations and the footbridge dilemma. In a post hoc analysis, restricting the data set to dilemma actions requiring personal force and instrumentality, we found an increased effect of intuitive deontology (OR = 1.30, 95% CI [1.19, 1.42]). Results question the universality of intuitive deontology, inform current discussions on the effect’s underlying mechanisms, and call for more carefully designed studies testing the effect.