People and Community

Psychologist explains purpose and pitfalls of disgust

The emotion, an ancient mechanism meant to keep us healthy, isn’t doing much to protect us against coronavirus—because COVID-19 does not offer the usual visible cues that protect us from sick people—shared Debra Lieberman, evolutionary psychologist and University of Miami associate professor.
The stigma of leprosy endures in India, even though the country has made great strides against the disease, which is neither highly contagious nor fatal. Now the number of new annual cases has risen slightly after years of steady decline, and medical experts say the enormous fear surrounding leprosy is hindering efforts to finally eliminate it.(AP Photo/Manish Swarup)
The stigma of leprosy endures in India, even though the country has made great strides against the disease, which is neither highly contagious nor fatal. Photo: Associated Press

In medieval times, lepers—suffering from a disease that disfigured its victims with skin ulcers—would wear bells around their necks to warn people they were coming.

That measure was taken not only to protect others from infection but also to avoid the physical disgust many would show when confronted with such a sick person.

Debra Lieberman

Disgust is an ancient and primal mechanism, ingrained in humans to help avoid contamination and disease, said Debra Lieberman, associate professor in the Department of Psychology in the College of Arts and Sciences and evolutionary psychologist who has spent the past two decades studying disgust.

Disgust causes us to recoil from fluids and objects that emit cues indicating they could be dangerous. This includes bodily fluids such as urine, feces, pus, and blood.

“Disgust activates when we perceive—through sight, smell, or contact—cues that would have indicated in ancestral environments that something could have made us sick,” said Lieberman. “In addition to body fluids, certain animals like cockroaches and maggots would have elicited disgust because these animals tend to signal the presence of rotting meats and foods.”

The coronavirus, like many viruses and pathogenic infections, can be tricky because carriers of the virus do not look sick. A carrier may be asymptomatic yet able to infect dozens of healthy people, since there are no visible or physical manifestations of the disease.

To some degree, this is why many people don’t see the benefit of isolation and are still congregating in groups at their homes and in some public spaces, said Lieberman.

“We are being told to stay away from people we care about who look healthy,” she said. “Without much else to go on, this does not compute in our brain, which is saying: ‘But they look healthy and they are my friends, so why do I need to stay away from them?’”

With the coronavirus, people must be much more individually and communally responsible and self-isolate, even as their brains are completely baffled by the experience. But another side effect of disgust is also a moral one, said Lieberman. 

“Disgust seeps into moral judgment,” she said. According to Lieberman, personal feelings of disgust,, especially when they become part of public discourse, can influence norms and behaviors.

The problem arises when personally held beliefs “fuel norms that condemn the behavior of others, thereby leading to, in some cases, moral bonfires that invariably target a particular group of individuals,” Lieberman wrote in a blog on the Psychology Today website. 

According to Lieberman, “Individuals of high social leverage, when they express personal disgust toward, say, a virus that appears to originate from China and then call it a ‘Chinese virus,’ has the effect—intended or not—of inciting exploitative behaviors against Asian-American citizens, something that the media has covered. Disgust coordinates and promotes condemnation.”

Lieberman warns that this kind of disgust mechanism is dangerous because it can lead to curtailment of individual freedoms. “We should be wary of disgust when it crosses the boundary from guiding one’s own behaviors to proscribing the behaviors of others,” she added.