The Roles of Emotion and Reason on Moral Judgments - A Cognitive Neuroscience Perspective

            

In the field of cognitive science, there exist two opposing models for the roles of emotion and reasoning in moral judgment. The Humean view asserts that emotions determine the judgment and reason – a slave to emotion – functions as a tool for post hoc rationalization. The Jeffersonian view argues that both emotions and reason determine moral judgments. The two articles in this paper each support one of these opposing models. Wheatley and Haidt (2005) found their data to be consistent with the Humean model while Koenigs, Young, Adolphs, Tranel, Cushman, Hauser and Damasio (2007) found their data consistent with the Jeffersonian model. An analysis of these articles reveals that the findings in Wheatley and Haidt (2005) can be viewed as consistent with the Jeffersonian model and Koenigs et al. (2007) simply builds upon those findings. These studies show that both emotions and reason influence moral judgment.

Study 1
Wheatley and Haidt (2005) hypothesized that hypnotically induced disgust would increase the severity of moral judgments. Half the subjects received a posthypnotic suggestion to feel disgust when reading the word often and the other half when reading the word take. They then rated how morally wrong and how disgusting moral transgressions in vignettes were. The subjects were presented with one of two versions of each vignette: one which contained the word take and the other the word often. Participants rated vignettes as more disgusting and morally wrong when the disgust word was present than when it was absent, thus supporting the hypothesis.

To ensure that disgust influenced moral judgments and did not simply make all ratings more negative, Wheatley and Haidt (2005) conducted a modified version of the previous experiment containing a third (control) rating in which the subjects judged a non-transgression item related to the vignette. There was no significant difference between the ratings of items when the disgust word was present than when absent, suggesting that disgust did not make all ratings more negative. However, disgust did make moral judgments more severe even in the case of the “Student Council story,” which contained no moral transgression; when questioned on this particular story, experimenters reported the puzzled subjects answering with post hoc rationalizations. This is consistent with a model in which intuition and emotions determine moral judgments.

Study 2
Koenigs et al. (2007) investigated neurologically how damage to emotion-related areas of the brain influence moral judgment. There were three types of subjects, all with reasonably intact intellects. The first were normal comparison subjects (NC). The second were patients with adult-onset damage to the ventromedial prefrontal cortex (VMPC), a brain region associated with generation of social emotions. The third were brain-damaged comparison (BDC) patients with lesions excluding emotion-related regions of the brain. The subjects either endorsed or rejected actions in fifty hypothetical scenarios. Scenarios were classified as non-moral, impersonal or personal. Personal scenarios were distinguished for their higher emotional salience, determined by a separate group of neurologically normal subjects. Personal scenarios were then separated into high-conflict and low-conflict scenarios based on the level of agreement within and between NC and BDC groups. These high-conflict scenarios were assumed to feature intense competition between utilitarian considerations and an emotional aversion to harming others, a level of competition not present in the low-conflict scenarios. VMPC patients differed from NC and BDC patients only in personal high-conflict scenarios in which they endorsed actions more often than the other groups. Other scenarios elicited reasoned responses from all groups, as demonstrated by the fact that the VMPC group did not differ from the others. The divergence in the personal high-conflict scenarios demonstrates that emotions began to overpower reason in the BDC and NC groups, but not in the VMPC group.

Resolving the "Opposing" Views
Although Wheatley and Haidt (2005) claimed to support a model for moral judgment in conflict with that of Koenigs et al. (2007), it can be argued that Wheatley and Haidt (2005) actually provides further justification for the model proposed by Koenigs et al. (2007). By hypnotically inducing disgust, Wheatley and Haidt (2005) tremendously increased the emotional salience of the vignettes. In this manner, that emotional impact is similar to that found in personal high-conflict scenarios in Koenigs et al. (2007). Both articles would agree that in such scenarios which elicit a strong emotional response, that emotion determines the moral judgment. Thus, Koenigs et al. (2007) simply builds upon the findings of Wheatley and Haidt (2005) to demonstrate that in cases of lower emotional intensity (impersonal scenarios), reason has far more influence. These articles can be reconciled to support the Jeffersonian model in which both reason and emotions influence judgment.

Reconciling the two articles by viewing the emotion elicited by the disgust word in Wheatley and Haidt (2005) as similar to that elicited by personal high-conflict scenarios in Koenigs et al. (2007) contributes much to an understanding of the basis for moral judgment. It provides data consistent with the Jeffersonian model in which both emotions and reason influence moral judgments. In scenarios where the emotional response is minimal, reason dominates as opposed to cases in which the emotional response is strong where reason becomes a slave to emotion.