Influences of Catastrophic Events on Ethical Judgments: A case from the Great East Japan Earthquake

The present study examined whether and how moral judgments in classic trolley dilemma scenarios changed following a major real-life event – the 2011 Great East Japan Earthquake. A longitudinal survey of 840 adults assessed decisions in two trolley problem scenarios (an impersonal “lever” version and a personal “footbridge” version) before and after the disaster, along with individual difference measures (Belief in a Just World, internal locus of control) and demographics. We analyzed changes in ethical choices (to sacrifice one person to save five or not), their directionality, and predictors of such changes. Results showed a significant increase in decision instability in the personal scenario: about 30% of participants altered their choice post-disaster, compared to 19% in the impersonal scenario. However, in the impersonal scenario more participants shifted from a utilitarian choice (sacrificing one) to a deontological choice (refusing to sacrifice) after the earthquake. By contrast, the personal scenario showed little net change. Belief in a just world (BJW) and internal locus of control scores significantly decreased from pre- to post-survey, indicating an erosion of just-world beliefs and personal control after the disaster. However, these changes did not directly predict who changed their moral decisions. Logistic regression analyses revealed that pre-existing individual differences played a role in moral stability: for the impersonal dilemma, higher BJW was associated with more consistent (unchanged) moral judgments, and women were more likely than men to alter their decision. In the personal dilemma, a lower internal locus of control predicted greater likelihood of changing one’s decision, and those who were students or in part-time employment showed higher odds of change than full-time workers. Model prediction was above chance but indicated substantial unexplained variance, underscoring the complexity of moral judgment dynamics. In sum, the present study provides evidence that a profound contextual event can subtly shift moral decision-making, and that certain individual dispositions confer stability in one’s ethical choices.