Researchers at the London School of Hygiene and Tropical Medicine surveyed more than 2,500 people online, asking them to rate their levels of disgust at 75 potential scenarios ranging from ‘no disgust’ to ‘extreme disgust’.

They subsequently identified six common categories of disgust and found that women reacted to each of these with greater levels of disgust than men.

These included scenarios related to poor hygiene, such as body odour and un-flushed toilets; animal contamination; out-of-date foods and risky sexual behaviours.

According to lead author Val Curtis, these scenarios provoke disgust due to an ancestral inclination to avoid what we believe might cause infection.  

“Disgust is a system in the brain that causes us to reject and avoid the things that would have made our ancestors sick,” Curtis told The Independent.

“So we tend to avoid things like off food, skin lesions, sex with promiscuous people, people with odd appearances, poor hygiene.

"In the past these might have signified infection. Of course, they may not today.”

For example, historically, coming into contact with expired foods might’ve led to cholera whereas encountering people with poor hygiene could’ve transmitted a harmful disease like leprosy.

Meanwhile, being sexually promiscuous could’ve lead to syphilis.

Out of the six common categories, pus-releasing wounds was deemed the most disgusting, with lack of hygiene following closely behind.

Curtis explained that it’s crucial to understand what causes disgust from both an emotional and public health perspective, arguing that it could lead to the reduction of disease:

“We need to understand how we respond to infection threat so we can keep people healthy,” she said, “for example, hyping up disgust in public health messaging is one strategy to get people to wash their hands.”

As for the disparity in terms of gender, Curtis explained that this boils down to women doing better in reproductive terms when they avoid scenarios that may threaten them or their children with disease.

Men may do the same but they are also more likely to take risks and therefore be less disgusted by things than their child-bearing counterparts.

Published in the Royal Society’s Philosophical Transactions B journal, also included on the list of possibly disgusting scenarios was atypical appearance, with facial deformity and skin conditions causing some participants high levels of disgust despite not being a medical threat.

Speaking on BBC Radio 4's Today show, Curtis explained that it's crucial to acknowledge these tacit levels disgust in order to reduce the stigma we may subconsciously attach to them.

She recalled a recent incident on a bus, during which she noticed a young woman "with a really bad breakout" on her face with nobody sat next to her.

"Because I'm a disgustologist I know that people were responding as if that person had an infectious disease because for our ancestors, it would've been advantageous to respond in that way.

"I knew that it was highly unlikely in the modern world that we live in that that was an infectious disease so I went and sat next to her.

"We stigmatise people unconsciously," she added.

"We need to overcome those instincts."

More about: life