Nobody likes being disgusted, but while this overwhelming emotional response may make you feel sick to your stomach, it turns out that’s a good thing.
Disgust has long been characterized as an emotion that helped our ancestors thwart infection. However, a new research suggests that the human disgust system is likely responsive to a lot of other things beyond just infection, including people, activities, and oddly shaped objects that potentially pose risks of disease.
Disease control researcher and ‘disgustologist’ Val Curtis from the London School of Hygiene & Tropical Medicine explains,
“This type of disease avoidance behavior is increasingly evident in animals, and so leads us to believe it is evolutionarily very ancient.”
Researchers from the London School of Hygiene & Tropical Medicine (LSHTM) have taken up this study in order to remove the stigma from diseases as well as foster healthy habits in the population, notes a release from the LSHTM.
The researchers surveyed more than 2,500 people, presenting them with a gallery of grossness: 75 revolting scenarios potentially suggestive of infectious vectors, which the participants had to rate on a scale from ‘no disgust’ to ‘extreme disgust’.
Nothing was off limits. Things like: accidentally borrowing someone else’s roll-on deodorant; noticing small red dots on your lover’s genitals; or feeling someone cough into your face.
Participants also had to rate the prospect of being licked by a stray dog; sharing an office with a co-worker who has a weeping eye infection; squashing a slug in bare feet, and sitting in front of a vomiting man on an airplane.
When the hypothetical stench cleared, Curtis was able to classify six distinct triggers of disgust sure to make most people want to hurl. Here, they are:
- Bad hygiene – displays or physical evidence of poor hygiene.
- Creepy Crawlies – disease-carrying “vermin” such as mice and mosquitoes.
- Scandalous sex – promiscuous sexual activities linked to spreading STDs.
- Skin diseases – signs of infected wounds such as blisters, boils, and pus.
- Rotten food – edibles that show signs of spoilage such as mold and maggots.
- Atypical appearance – infections, abnormal body shapes, and deformities, as well as symptoms of sickness such as coughing.
According to Curtis and her co-author Mícheál de Barra, many of these sources of disgust can be tied to a clear source of life-threatening disease and other hazards. Rats, mosquitos, and other tiny terrors can carry deadly illnesses, and the rotten-smelling meat won’t do your stomach any favors. Similarly, signs of bad hygiene can preface epidemics large and small, unhygienic sex is a great way to catch something awful, and many infectious diseases are transmitted by contact with affected skin.
As for the final category, well, it’s certainly not true that an amputated limb is contagious, or that a homeless person is more likely to give you a disease than your coworker who just came back from the bathroom without washing his hands. Sometimes, you need to ask yourself if that feeling of revulsion is coming from a real source of infection, toxin, or harm, or if it’s rooted in a social stereotype instead.
It’s healthy to listen to your sense of disgust, but it’s also good to understand where it’s coming from. Curtis explained,
“Although we knew the emotion of disgust was good for us, here we’ve been able to build on that, showing that disgust is structured, recognizing and responding to infection threats to protect us.”