We have an emotion of disgust. It appears to be a way of identifying and avoided things that can harm us by contagion. So things that smell or look or feel or taste in particular ways, reminding us of waste, rot, death, illness, disfigurement and the like, will disgust us. We will feel like vomiting, washing, withdrawing, gagging, and holding our noses. We have a standard facial expression. This emotional aversion protects us from contamination. We can also feel a sort of moral contamination, a sense of impurity. Apparently we do not need two emotions when one will do. We can also feel morally disgusted. The same bodily reactions will do; the same networks in the brain can do the processing; the same facial expression can signal.
Here is the abstract from Haidt, Rozin, Mccauley, Imada (1997), Body, Psyche, and Culture: The Relationship between Disgust and Morality:
“Core disgust” is a food related emotion that is rooted in evolution but is also a cultural product. Seven categories of disgust elicitors have been observed in an American sample. These include food, animals, body products, sexual deviance, body-envelope violations, poor hygiene, and contact with death. In addition, social concerns such as interpersonal contamination and socio-moral violations are also associated with disgust. Cross-cultural analyses of disgust and its elicitors using Israeli, Japanese, Greek and Hopi notions of disgust were undertaken. It was noted that disgust elicitors have expanded from food to the social order and have been found in many cultures. Explanations for this expansion are provided in terms of embodied schemata, which refer to imaginative structures or patterns of experience that are based on bodily knowledge or sensation. A mechanism is suggested whereby disgust elicitors are viewed as a prototypically defined category involving many of the embodied schemata of disgust. It is argued that each culture draws upon these schemata and its social and moral life is based on them.
And an abstract from Ritter and Preston (2011), Gross gods and icky atheism: Disgust responses to rejected religious beliefs:
Disgust is an emotional response that helps to maintain and protect physical and spiritual purity by signaling contamination and motivating the restoration of personal cleanliness. In the present research we predicted that disgust may be elicited by contact with outgroup religious beliefs, as these beliefs pose a threat to spiritual purity. Two experiments tested this prediction using a repeated taste-test paradigm in which participants tasted and rated a drink before and after copying a passage from an outgroup religion. In Experiment 1, Christian participants showed increased disgust after writing a passage from the Qur’an or Richard Dawkins’ The God Delusion, but not a control text. Experiment 2 replicated this effect, and also showed that contact with an ingroup religious belief (Christians copying from the Bible) did not elicit disgust. Moreover, Experiment 2 showed that disgust to rejected beliefs was eliminated when participants were allowed to wash their hands after copying the passage, symbolically restoring spiritual cleanliness. Together, these results provide evidence that contact with rejected religious beliefs elicits disgust by symbolically violating spiritual purity. Implications for intergroup relations between religious groups is discussed, and the role of disgust in the protection of beliefs that hold moral value.
What about prejudice against the disabled, obese and different cultures/races? Here is the abstract of Navarrete, Fessler, Eng (2006): Elevated ethnocentrism in the first trimester of pregnancy:
Recent research employing a disease-threat model of the psychology of intergroup attitudes has provided preliminary support for a link between subjectively disease-salient emotional states and ethnocentric attitudes. Because the first trimester of pregnancy is a period of particular vulnerability to infection, pregnant women offer an opportunity to further test this association. We explored the expression of intergroup attitudes in a sample of pregnant women from the United States. Consistent with the predictions of the disease-threat model, results from our cross-sectional study indicate that favoritism toward the ingroup peaks during the first trimester of pregnancy and decreases during the second and third trimesters. We discuss this finding in light of the possible contributions of cultural and biological factors affecting ethnocentrism.
Another bodily reaction, different than the disgust just discussed, is to bitterness. Bitter plants are more likely to contain poisons, which is probably why we can taste it and find the taste so unpleasant. But bitterness is also a trigger for a type of disgust tinged with moral outrage. Here is Eskine, Kacinik and Prinz (2011), Gustatory Disgust Influences Moral Judgment:
Can sweet-tasting substances trigger kind, favorable judgments about other people? What about substances that are disgusting and bitter? Various studies have linked physical disgust to moral disgust, but despite the rich and sometimes striking findings these studies have yielded, no research has explored morality in conjunction with taste, which can vary greatly and may differentially affect cognition. The research reported here tested the effects of taste perception on moral judgments. After consuming a sweet beverage, a bitter beverage, or water, participants rated a variety of moral transgressions. Results showed that taste perception significantly affected moral judgments, such that physical disgust (induced via a bitter taste) elicited feelings of moral disgust. Further, this effect was more pronounced in participants with politically conservative views than in participants with politically liberal views. Taken together, these differential findings suggest that embodied gustatory experiences may affect moral processing more than previously thought.
Various groups have found that the anterior insular cortex is active in situations involving revolting smells and sights, disgusted facial expressions, and moral disgust. It seems to be an area that connects internal and external perceptions. The feeling is not confined to insular activity but can even have motor affects. Here is the abstract for Lee and Schwartz (2010), Of dirty hands and dirty mouths: Embodiment of the moral purity metaphor is specific to the motor modality involved in moral transgression:
Abstract thoughts about morality are grounded in concrete experiences of physical cleanliness. Noting that natural language use expresses this metaphorical link with reference to the body part involved in an immoral act (e.g., a dirty mouth; dirty hands), we address the role of motor modality in the embodiment of moral purity. We find that conveying a malevolent lie on voicemail (using the mouth) increases the desire to clean ones mouth, but not the desire to clean ones hands; conversely, conveying the same lie on email (using ones hands) increases the desire to clean ones hands, but not ones mouth. Additional findings suggest that conveying a benevolent message may decrease the desire to clean the involved body part. Secondary analyses of earlier studies further support the assumption that the embodiment of moral purity is specific to the motor modality involved in the act.
They also found the opposite –
Note, however, that people not only avoid physical contact with morally tainted people and objects, but also seek physical contact with virtuous ones. Hence, they may not only attempt to remove the metaphorical residue of immoral acts, but also avoid removing the residue of virtuous acts, making mouthwash (hand-sanitizer) particularly unappealing after conveying a virtuous message on voicemail (email).
So moral cognition has a bodily dimension, but exactly what is this moral cognition. I have heard people say that all you need is the Golden Rule, that covers it. Others say look at the outcome and do what causes the least total harm or most total good. Or some say to just follow the good book. Pinker lists five sorts of moral principles: harm, fairness, community, authority and purity. He may be right but maybe they collapse into three or break up into twenty. (Just my natural suspicion of exactly 7 types of personality or 3 types of communication etc.) However, Pinker does give a good description of his primary colors of our moral sense: do unto others as you would have done to you (fairness); do not commit adultery (purity); honour your father and mother (authority); do no murder (harm); and do not covet your neighbours ox (community). Priority between the types depends on the individual and the times. My point here is that morality may be a rag bag of different sensitivities and only grouped together as one sense by the nature of their embodiment. By circumstance a number of different things become entangled with the same or similar disgust signals from the body. I assume that morality is also held together by feelings of guilt and shame and they are also embodied signals. (vis Lady MacBeth’s hand washing).
We consciously know what is wrong because our body finds wrong things disgusting and those feelings are available to consciousness from bodily signals of disgust. If we do wrong we know it consciously because we feel the bodily effects of guilt and shame. Our brains have learned (or were born with) what it should be disgusted by. But this is not a perception and so seems to be unable to be part of the content of consciousness. The reaction of the body to disgust can be perceived and therefore enter the conscious model.
This is the fifth in a series on embodied cognition. There will be future ones still to come.
Here are the first four in the series: