Why cannot reasons change your moral decisions? Because they are not persuasive enough: A comment on Stanley et al. (2018)

Stanley et al. (2018) found that the consideration of reasons rarely induced people to change their moral decisions. We challenged this article by assuming what caused such a null or weak effect was that the persuasiveness of reasons provided to oppose the initial decisions was not strong enough. To verify our assumption, this study used Stanley et al.’s (2018) experimental paradigm and manipulated the levels of persuasiveness of reasons. The results revealed (1) that not only strong opposing reasons but also weak affirming reasons could induce changes in moral decision-making and increase decision confidence after altering the decisions; (2) that people with a weak decision confidence tended to change their initial decisions after evaluation of reasons; and (3) that people who maintained their decisions after considering weak opposing reasons enhanced rather than reduced their decision confidence. Overall, these findings demonstrated that moral decision change was a composite outcome of the interaction among reason type, reason persuasiveness and initial decision confidence and that low-quality argumentation had a boomerang effect on moral persuasion. This study re-lifted the role of rational reasoning in moral decision-making and revising, thus posing important amendments to Stanley et al.’s (2018) findings.