Proceedings of the Annual Meeting of the Cognitive Science Society

We extend universal moral grammar theory (UMGT) with nonmonotonic logic. Our experiment shows that such revision is necessary as it allows to account for the effects of alleviations and aggravations in moral reasoning. Our new theory updates UMGT from classical to non-monotonic logic, which reflects the incompleteness of information and uncertainty in actual human reasoning. In addition, it provides an explanation of the paradoxical findings in the moral dilemma of the Trolley problem and the Knobe effect