Neuroscience and Judgment

We interrogate and criticise the reliance, by Joshua Greene and many others, on the results of functional brain imaging. Greene’s ‘dual-mode’ model of brain function draws deeply on these findings. The reliance typically caricatures brain anatomy and function, concentrating on gross structures rather than micro-circuits, ignoring the degree of cross-connection in brain circuitry, failing to take into account a mass of confounding variables, and implying that the ‘intuitive’ areas of the brain are evolutionarily primitive. We examine Greene’s “myopic module” hypothesis and show, contra Greene, that it fails to explain our differing responses to various trolley scenarios. We also examine his attempt to “debunk” the moral distinction between acts and omissions and argue that he fails to do so. We cast doubt, too, on his claim that, when not driven by “automatic settings” the inherent flexibility of manual mode thinking makes it more reliable. We then turn to the neurobiological roots of altruism and selfishness, including the role of mirror neurones, and observe that (contra Greene and others) the real moral world is not neatly divisible into personal/impersonal moral choices. If intuitions are indeed correctly characterised as rough-and-ready heuristics, our embodied nature means that we cannot simply ignore the operation of those heuristics in understanding our moral decision-making. While this is sometimes acknowledged by utilitarians, they have yet to appreciate the full ramifications of this for their utilitarian theory.