David Pizarro: the science, morality and politics of disgust

From Labour Day, 10:10 am on 24 October 2016

Just saying the word 'moist' is enough to make some people retch, but new findings show our political bent and our capacity for disgust go hand-in-hand.

Cornell University psychologist David Pizarro is an expert on the science of disgust who has uncovered connections between disgust and political persuasion.

Professor Pizarro, who also hosts the morality podcast Very Bad Wizards, told Labour Day presenter Charlotte Graham that the disgust response has helped keep humans alive.

For example, evolutionarily, people who were disgusted by the bodily fluids of others were less likely to get sick - but as a reflex response it was not good at changing to fit the actual dangers of the modern world.

David Pizarro

    David Pizarro. Photo: Supplied

"For instance I know that shaking hands is actually way more likely to get me sick than seeing dog poop on the street. But my disgust is not rational.

"It lags, it's not tuned to the right information, it is a very very rough tool," he said.

The emotion of disgust was often used when people were making moral arguments, Professor Pizarro said, especially when it came to behaviours which could be interpreted as having a moral component, such as sexuality.

And he said cultures that developed in parts of the world which were historically more likely to have pathogens and diseases were more also more likely to have conservative ideas about food, sexuality, cleanliness and exposure to strangers.

Professor Pizarro said during his study he measured peoples' disgust levels and then compared them with their moral beliefs. However, the findings pointed in a different direction.

"Over and over again ... when we just happened to ask them about their political orientation, that people who were really easily disgusted were more politically conservative."

This association has been found across 30 different countries in 21 languages, he said.

Republican presidential nominee Donald Trump gives the thumbs-up after speaking at a campaign event at the Eisenhower Hotel in Gettysburg, Pennsylvania on October 22, 2016.

US Republican presidential candidate Donald Trump is often disgusted by world around him. Photo: AFP

He said work in the social sciences had shown that different personality traits were associated with differing political views, with left-leaning people more open to novel experiences and right-leaning preferring to avoid threats.

"So those two motivations, that threat avoidance and ... exploration, seem to be at the heart of liberal and conservatives.

"It may be that disgust is part of this larger threat system," Professor Pizarro said.

He said the most common disgust triggers across cultures and age groups were bodily products.

"Tears don't seem to illicit disgust in the same way but almost everything else that comes out of other peoples bodies is pretty gross to most people.

"And that makes sense because those would be things that are associated with disease, so in that sense it is a pretty smart emotion," Professor Pizarro said.

He said sight and smell and taste were the main triggers of the disgust response, but just hearing a word was enough to set some people off.

"There are words that seem to reliable elicit disgust in people, like the word moist.

"I don't know why, but that is probably because we have built up associations with certain words that reliably make us think of a sight or a smell or a sound," Professor Pizarro said.