Theories of moral judgment have long emphasized reasoning and conscious thought while minimizing the role of contextual influences, such as affective processes. However, we showed that emotional feelings can change people’s moral judgments (Schnall, Haidt, Clore & Jordan, 2008). In several experiments participants made more severe moral judgments while experiencing extraneous feelings of disgust. Other researchers built on this finding and replicated and extended it. We also investigated whether making salient the notion of physical purity could have the reverse effect, and make moral judgments less severe (Schnall, Benton & Harvey, 2008). These findings support the idea that moral judgment can be driven by intuitive processes, rather than deliberate reasoning.
One of those intuitions appears to be physical purity, because it has a strong connection to moral purity (Schnall, 2011; Schnall & Cannon, 2012). Indeed, already fifty years ago the anthropologist Mary Douglas pointed to the central role of notions of purity and pollution in social contexts (see chapters in Duschinsky, Schnall, & Weiss, 2016). In addition, several other moral foundations are manifested in affective facial activity, which in turn predicts moral judgment (Cannon, Schnall, & White, 2011). In applied contexts intuitions play a role when people condemn means to alter physical or mental abilities, such as the use of cognitive enhancing drugs (“smart drugs”) (Scheske & Schnall, 2012).
While our early work suggested that disgust can make moral judgments more harsh, while cleanliness can make them less harsh, a recent review paper Schnall (2017) argues that disgust more generally serves the role to act as a mechanism geared toward loss aversion. More specifically, disgust is the response that ensures protection of precious resources, the most important one being one’s own body. Beyond that, however, it also encourages a conservative style of approaching resource decisions, for example, in the context of economic games.
Moral emotions also influence behaviour, and for example, we showed that participants experiencing moral elevation when witnessing somebody perform a good deed were inspired to perform a good deed themselves (Schnall, Roper & Fessler, 2010). Furthermore, the effects cannot be explained by people simply trying to feel better about themselves by helping: In fact, the effect of moral elevation on helping was especially pronounced for participants who spontaneously recalled previous prosocial behaviours when given the opportunity to affirm their own positive qualities (Schnall & Roper, 2012).
Recent unpublished research has examined moral elevation in comparison with admiration for skill, and in general, the different cognitive and emotional responses evoked by witnessing other people’s exceptional moral actions, or their admirable abilities. Overall this work suggests that emotional factors exert a powerful influence on moral thought and behaviour that goes well beyond rational consideration, which is of particular relevance in legal contexts.