Does Disgust Influence Moral Judgment?

Abstract

Recent empirical research seems to show that emotions play a substantial role in moral judgment. Perhaps the most important line of support for this claim focuses on disgust. A number of philosophers and scientists argue that there is adequate evidence showing that disgust significantly influences various moral judgments. And this has been used to support or undermine a range of philosophical theories, such as sentimentalism and deontology. I argue that the existing evidence does not support such arguments. At best it suggests something rather different: that moral judgment can have a minor emotive function, in addition to a substantially descriptive one.

Keywords:

• emotionism
• social intuitionism
• cognitivism
• emotivism
• expressivism
• moralization

Notes

¹ Haidt should probably no longer be classified as a sentimentalist. In more recent work he claims not to be contrasting reason and emotion, but rather ‘two kinds of cognition’, neither of which is ‘always a part of an emotional response’ [Haidt and Björklund 2008: 200]. His concern is more to show that moral judgment has less to do with explicit conscious reasoning.

² Thanks to Thalia Wheatley (via Walter Sinnott-Armstrong) for clarifying this issue and providing the earlier version of the paper.

³ Eskine, Kacinik, and Prinz [2011] have recently extended the findings of Wheatley and Haidt by using their stimuli but manipulating gustatory disgust. As they didn't use hypnotism, the effect observed was not limited to a subgroup of highly hypnotizable participants. However, their study and results possess all the other limitations found in Wheatley and Haidt's hypnotism experiments.

⁴ One might merely read Greene as claiming that disgust makes condemnation ‘more likely’ in that disgust increased mean morality ratings in that direction, even if the mean (or any subject's rating) doesn't amount to something we should count as condemnation (e.g. by being significantly above the midpoint). But the reading of ‘more likely’ that is required for his main argument is something like the stronger one preceding the quotation.

⁵ Some might also point to Shaun Nichols's work on disgust and the moral/conventional distinction. But Nichols didn't manipulate disgust; he created two groups based on their disgust sensitivity. More importantly, he found no statistically significant difference between these groups’ judgments about the permissibility of the relevant transgressions, which comes closest to a moral judgment [2002: 231].

⁶ I don't believe there is any reason, however, to think that scales for measuring attitudes (like the Likert scale) are inherently problematic. One just needs to be sensitive to the issues involved [cf. May and Holton 2012].

⁷ The general idea here is that we should have a clearer calibration of our instruments in new areas of psychological research. My thinking about this was influenced by a presentation of Jonathan Weinberg's at a mini-conference on Experimental Epistemology in 2011.

⁸ Some of the vignettes that yielded an effect for Haidt and colleagues don't seem to fall within the purity domain (e.g. Bribery, Film, Student Council), which may conflict with the conclusion drawn by Horberg et al. The problems we have raised here for the experiments conducted by Haidt and his collaborators cast some doubt on the conflict, but further research is surely required to fully adjudicate the issue.

⁹ Of course, we must also pay close attention to whether the results connecting disgust and moral judgment can be replicated, especially after making relevant improvements. For some preliminary evidence suggesting problems with replication, see Case, Oaten, and Stevenson [2012], although their experiments aren't necessarily the last word on the matter.

¹⁰ Thanks especially to Daniel Nolan for discussion on this point.

¹¹ Many thanks to Nic Southwood for discussion of these issues.

¹² For comments on drafts of this paper, I thank C. Daniel Batson, Wesley Buckwalter, Zachary Horne, Andy Lamey, Walter Sinnott-Armstrong, Aaron Zimmerman, and the anonymous referees for this journal. Many thanks also to audiences at Monash University, the Australian National University, Macquarie University, and the Australasian Association of Philosophy conference. I received exceptional feedback from so many, but especially Trevor Case, David Chalmers, Ben Fraser, Catriona Mackenzie, Jonathan McGuire, John Maier, Christina Majoinen, Daniel Nolan, and Nicholas Southwood.