The Dual Track Theory of Moral Decision-Making: a Critique of the Neuroimaging Evidence

The dual-track theory of moral reasoning has received considerable attention due to the neuroimaging work of Greene et al. Greene et al. claimed that certain kinds of moral dilemmas activated brain regions specific to emotional responses, while others activated areas specific to cognition. This appears to indicate a dissociation between different types of moral reasoning. I re-evaluate these claims of specificity in light of subsequent empirical work. I argue that none of the cortical areas identified by Greene et al. are functionally specific: each is active in a wide variety of both cognitive and emotional tasks. I further argue that distinct activation across conditions is not strong evidence for dissociation. This undermines support for the dual-track hypothesis. I further argue that moral decision-making appears to activate a common network that underlies self-projection: the ability to imagine oneself from a variety of viewpoints in a variety of situations. I argue that the utilization of self-projection indicates a continuity between moral decision-making and other kinds of complex social deliberation. This may have normative consequences, but teasing them out will require careful attention to both empirical and philosophical concerns.