Our sense of morality has always been considered that something that separates us from the rest of the animal kingdom, making us superior through its complexity. But, like always, scientist come to tell us that we may not be in fact really that special and that our perception of what is moral and what is immoral may be strongly related to something as simple and primitive as our sense of disgust. So does immorality literally make us sick?

Our sense of disgust evolved as a necessity in order to avoid germs and disease, but lead author Hanah Chapman claims that studies have shown that is also involved in moral judgment, being as important as more complex processes of thought.

The study involved the examination of facial movements when the participants were asked to taste unpleasant liquids, watch photos depicting dirty toilets or wounds and then take part in a laboratory game, in which they were treated unfair. The results showed that seeing unpleasant photos or tasting disgusting liquids led to the same reactions as being subjected to unfair treatment.

Electromyography, which is a technique that uses small electrodes placed on the face in order to detect electrical activation when muscles contract was used especially to monitor the movement of the levator labii muscle, which raises the upper lip and makes the nose wrinkle,these are considered to be the main facial expressions of disgust. Te muscle contracted in all three cases.

This proves that our sense of morality may depend on instinct as much as on thought, possibly developing from an inborn’s preference for what tastes good, thus avoiding poisoning.