Disgust has become a hot topic in psychology research over the last decade or so, not least because findings have shown that the way we respond to physically disgusting threats, like disease-infested blood and puss, is closely related to the way we think about moral violations and moral concepts like purity (hence people’s reluctance to don a shirt purportedly worn by Adolf Hitler).
One repeated claim in this area is that we have evolved to be disgusted by any reminder that we are animals. For instance, the leading disgust and morality researchers Jonathan Haidt, Paul Rozin and Clark McCauley have stated that disgust is “a defensive emotion that guards against the recognition of our animality” and that “anything that reminds us that we are animals elicits disgust”. It’s a compelling idea that feeds into other areas of psychology, for example related to how we react to and cope with reminders of our mortality, and the way we often instinctively dehumanise criminals, pariahs and outsiders. The trouble is, nobody has actually put the claim to a robust test. Until now.
Across several surveys, Dolichan Kollareth and James Russell at Boston College tested the emotional reaction of hundreds of people from North America, and Northern and Southern India to various reminders of their animal nature. Their consistent finding, published in Cognition and Emotion, was that people found unpleasant animal reminders disgusting (for example, “You see a man with his intestines exposed after an accident” or “You are in a science class, and see a human hand preserved in a jar”), but that they were not disgusted by pleasant reminders that humans are animals (such as “You notice that a woman’s long silky hair reminds you of a horse’s mane” and “Tickling the tummy of a baby reminds you of the way your pet dog responds when you tickle his belly”).
The surveys also asked participants how much they were reminded that humans are animals by the different stories, and how much they made them fearful for their health. In fact, participants were reminded more of their animal natures by the pleasant stories than the unpleasant ones, and levels of disgust in response to the unpleasant animal reminders did not correlate with how much those unpleasant reminders made them think of their animal natures.
Conversely, the disgusting unpleasant animal reminders made participants think more about threats to their health than the pleasant animal reminders (this was especially true for North American participants for whom disgust and thoughts of health risk were correlated for the unpleasant pictures). All this suggests to Kollareth and Russell that being reminded that we are animals is not disgusting per se, but rather than unpleasant animal reminders are disgusting because of their connotations for health.
This same general pattern of results stayed the same in more surveys, including one in which the researchers tested the effects of a simple statement about our animal natures: “Human beings are like any other animals. They are born, eat, procreate, live and eventually die like any other animal”, and another in which participants were shown pairs of pictures showing an animal and a person doing the same animalistic thing, either something unpleasant to look at, such as urinating, or pleasant, such as snuggling up together, always complemented by a reminder statement about our animal natures. Participants were not disgusted by the simple reminder statement, and while they were disgusted by the unpleasant animal-reminder pictures, they were not disgusted by the pleasant ones.
To Kollareth and Russell’s knowledge this is the first ever direct empirical test of the claim, made repeatedly by leading disgust researchers, that we are disgusted by thoughts or reminders of the fact we are animals. The pair acknowledged that their research has some limitations that need addressing in the future, such as the reliance on participants reporting their own feelings of disgust (perhaps physiological or more implicit measures w0uld have produced different results).
In short, the new findings are consistent with the idea that we’re disgusted by anything that makes us think about risks of infection, but they do not support the oft-repeated idea that we are disgusted by reminders that we are animals. “An animal reminder per se is not disgusting,” Kollareth and Russell conclude. “Some disgusting events remind us of our animal nature, but they are not disgusting because they remind us of our animal nature.”