There are a lot of gross things out there that make our skin crawl – wriggling worms, oozing pus, the stench of sick, to name a few. Now researchers have revealed that there are six common categories that make us feel disgusted, publishing their findings in Philosophical Transactions of the Royal Society B.
Disgust is an instinctive emotion that we feel when we see something horrible that we want to avoid. The sensation has cleverly evolved to protect us from disease, as we stay well away from anything revolting that could make us sick. And it’s not just us, disgust occurs across the animal kingdom, with many species steering clear of poop that could contain nasty parasites or disposing of sickly members of the group to prevent further infections.
The scientists surveyed over 2,500 people online, giving them 75 potentially disgusting scenarios, from the sound of a sneeze to pus-filled skin lesions. The volunteers then had to rate how grossed out they were on a scale ranging from “no disgust” to “extreme disgust”. Infected pus-filled wounds repulsed the participants the most.
Using the results of the survey, the researchers managed to categorize things that disgust us into six groups – animals, food, hygiene, sex, lesions, and atypical appearance.
Animals (obviously doesn’t relate to all creatures) – kittens and puppies certainly don’t make us feel disgusted. Instead, this group includes things like raw meat, worms, cockroaches, slugs, and things teeming with creepy-crawlies. This makes sense as these kinds of animals can make us ill directly, or indirectly by contaminating our food.
Food – this group basically just refers to rotting foods that look or smell disgusting. We have evolved to avoid these foodstuffs as eating them can make us seriously ill.
Hygiene, or rather a lack of, makes us feel disgusted, particularly when we observe someone else acting unhygienically. Examples given by the researchers include watching someone picking their nose, someone coughing in your face, and listening to someone constantly sniffing.
Sex doesn’t refer to sex in general but rather risky sexual behaviors that could make you more likely to get an STI. These include things like discovering that your partner slept with a prostitute, having sex with someone you’ve only just met, and hearing about someone who had sex with seven different people in one day. Funnily enough, women felt more disgusted than men.
Lesions includes anything to do with issues with the skin or body’s surface. Unsurprisingly we get pretty repulsed by oozing wounds, weepy eyes, and genital sores.
Atypical appearance relates to people and animals that don’t look how you’d expect – a cat with no hair for instance, or a person missing a thumb. Another example given in the study is an “obese woman sunbathing”. This group also included people behaving in an unusual way due to illness, such as wheezing heavily.
The findings confirm something known as “parasite avoidance theory”, the idea that we evolved to feel disgust to protect us from disease. We obviously can’t see tiny microbes, so become disgusted by things that imply they’re there, like decaying food or someone vomiting, and act accordingly.
“Although we only really came to understand how diseases transmit in the 19th century, it’s clear from these results that people have an intuitive sense of what to avoid in their environment," said research co-leader Micheal de Barra. “Our long coevolution with disease has 'wired in' this intuitive sense of what can cause infection.”