Moral Decision-Making in Trolley Problems and Variants: How Do Participants' Perspectives, Borderline Personality Traits, and Empathy Predict Choices?

The aim of the present study was to demonstrate and extend the causal effect of participants' perspectives on moral decision-making using trolley problems and variants. Additionally, we investigated whether empathy and borderline (BDL) personality traits predicted participants' choices in these scenarios. We used both a classical trolley problem (a causing harm scenario) and an everyday trolley-like problem (a causing inconvenience scenario). Participants (N = 427, women: 54%) completed BDL traits and empathy questionnaires and, randomly, the two types of trolley problems, presenting both three different perspectives. Our study provided strong evidence that the perspective from which participants were enrolled in the trolley problem caused significant changes in their moral decision-making. Furthermore, we found that affective empathy and BDL traits significantly predicted participants' decisions in the causing inconvenience scenario, while only BDL traits predicted choices in the causing harm scenario. This study was original in providing new experimental materials, causal results, and highlighting the significant influence of BDL traits and affective empathy on moral decision-making. These findings raised fundamental questions, which are further developed in the discussion section.