Do Obligations Follow the Mind or Body?

Do you persist as the same person over time because you keep the same mind or because you keep the same body? Philosophers have long investigated this question of personal identity with thought experiments. Cognitive scientists have joined this tradition by assessing lay intuitions about those cases. Much of this work has focused on judgments of identity continuity. But identity also has practical significance: obligations are tagged to one's identity over time. Understanding how someone persists as the same person over time could provide insight into how and why moral and legal obligations persist. In this paper, we investigate judgments of obligations in hypothetical cases where a person's mind and body diverge (e.g., brain transplant cases). We find a striking pattern of results: In assigning obligations in these identity test cases, people are divided among three groups: "body-followers," "mind-followers," and "splitters"-people who say that the obligation is split between the mind and the body. Across studies, responses are predicted by a variety of factors, including mind/body dualism, essentialism, education, and professional training. When we give this task to professional lawyers, accountants, and bankers, we find they are more inclined to rely on bodily continuity in tracking obligations. These findings reveal not only the heterogeneity of intuitions about identity but how these intuitions relate to the legal standing of an individual's obligations.