FlashReport Dual-process morality and the personal / impersonal distinction : A reply to McGuire , Langdon , Coltheart , and Mackenzie

A substantial body of research supports a dual-process theory of moral judgment, according to which characteristically deontological judgments are driven by automatic emotional responses, while characteristically utilitarian judgments are driven by controlled cognitive processes. This theory was initially supported by neuroimaging and reaction time (RT) data. McGuire et al. have reanalyzed these initial RT data and claim that, in light of their findings, the dual-process theory of moral judgment and the personal/impersonal distinction now lack support. While McGuire and colleagues have convincingly overturned Greene et al.’s interpretation of their original RT data, their claim that the dual-process theory now lacks support overstates the implications of their findings. McGuire and colleagues ignore the results of several more recent behavioral studies, including the study that bears most directly on their critique. They dismiss without adequate justification the results of a more recent neuroimaging study, three more recent patient studies, and an emotion–induction study. Their broader critique is based largely on their conflation of the dual-process theory with the personal/impersonal distinction, which are independent. 2009 Elsevier Inc. All rights reserved. My collaborators and I have developed a dual-process theory of moral judgment (Greene, 2007a; Greene, Morelli, Lowenberg, Nystrom, & Cohen, 2008; Greene, Nystrom, Engell, Darley, & Cohen, 2004; Greene, Sommerville, Nystrom, Darley, & Cohen, 2001), according to which characteristically deontological judgments (e.g. disapproving of killing one person to save several others) are driven by automatic emotional responses, while characteristically utilitarian judgments (e.g. approving of killing one to save several others) are driven by controlled cognitive processes. This line of research was inspired by a philosophical puzzle known as the Trolley Problem (Fischer & Ravizza, 1992; Thomson, 1985): In response to the switch dilemma (previously referred to as the trolley dilemma), people typically judge that it is morally acceptable to divert a runaway trolley that threatens five lives onto a side track, where it will run over and kill only one person instead (Greene et al., 2001; Mikhail, 2000; Petrinovich, O’Neill, & Jorgensen, 1993). In response to the contrasting footbridge dilemma, people typically judge that it is morally unacceptable to push someone off a footbridge and into the path of a speeding trolley, saving five people further down the track, but killing the person pushed. The ‘‘Problem” is to explain why people respond (or ought to respond) differently to these two dilemmas. In studying these dilemmas, our primary aim was to better understand the respective roles of emotional/automatic vs. controlled cognitive processes in moral judgment. More specifically, we aimed to test our dual-process theory by collecting functional magnetic resonance imaging (fMRI) and reaction time (RT) data to test the following two claims: (1) People’s characteristically deontological disapproval of actions like the one proposed in the footbridge dilemma are driven by automatic negative emotional responses. (2) Utilitarian approval of harmful actions is driven by controlled cognitive processes. (Utilitarian judgments occur often in response to dilemmas like the switch dilemma and less frequently in response to dilemmas like the footbridge dilemma.) Our secondary aim was to propose a preliminary theory concerning the features of the switch and footbridge dilemmas that cause people to respond so differently to them. This secondary aim was foisted upon us by the technical requirements of fMRI. We could not simply examine the switch and footbridge dilemmas in isolation because fMRI data are too noisy. Instead we had to develop two sets of dilemmas, one with the relevant features of the switch dilemma and one with the relevant features of the footbridge dilemma. We did not know which features were the relevant ones, but we hazarded a guess, which became the ‘‘personal/impersonal” distinction. Dilemmas, like the footbridge dilemma, in which the action would cause (a) serious bodily harm, (b) to a particular person or group, where (c) the harm does not result from deflecting an existing threat, were classified as ‘‘personal. ” The rest were classified as ‘‘impersonal. ” We were aware of problems with more familiar distinctions from the philosophical literature on the Trolley 0022-1031/$ see front matter ! 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jesp. 2009.01. 003 * Fax: +1 617 4953898. E-mail address: jgreene@wjh.harvard. edu Journal of Experimental Social Psychology xxx (2009) xxx–xxx