The killing baby Hitler dilemma: A novel paradigm for studying causal-temporal distance in moral decision-making

Classic moral dilemmas such as the trolley and footbridge problems involve immediate actions and certain consequences, limiting the study of how temporal and causal structure shapes moral judgment. The present study introduces a novel experimental paradigm—the Killing Baby Hitler (KBH) dilemma—to investigate how the causal-temporal structure linking a moral action to its consequences affects moral decision-making. Inspired by a well-known thought experiment in philosophy and popular culture, the scenario asks whether one should allow a drowning child, known to be Adolf Hitler, to die in order to prevent the future atrocities of the Holocaust. Participants (N=291) were randomly assigned to one of three conditions varying the target's position within the causal-temporal sequence leading to the Holocaust: Hitler himself, Hitler's father, or Hitler's grandfather. Participants also completed the footbridge dilemma and the Oxford Utilitarianism Scale. Results showed that causal-temporal distance significantly affected moral choice: as the target became more distant from the Holocaust, participants were more likely to endorse the deontological option. Logistic regression analyses confirmed causal-temporal distance as a robust predictor of moral judgment, even after controlling for utilitarian dispositions and sociodemographic variables. Instrumental harm was positively associated with utilitarian responses, whereas social desirability was unrelated to participants' choices. Responses to the KBH dilemma were not strongly associated with the footbridge dilemma, suggesting that the paradigm captures a distinct dimension of moral cognition. Overall, the findings highlight the importance of causal-temporal structure in moral decision-making and introduce the KBH dilemma as a flexible tool for studying delayed consequences.