Bad deeds smell

By morally condemning other people's actions, we activate our own brain centers of disgust.

“This is disgusting” - people say if they mean something unacceptable, unethical, immoral. In doing so, they really begin to feel disgust: scientists have found that any unacceptable actions of other people cause a literal feeling of disgust in the human brain, similar to that which occurs when sensing fetid odors. This was told by experts representing the University of Geneva: they decided to find out how the brain reacts to bad deeds - painfully or still with disgust.

At the beginning of the experiment, the participants were allowed to feel an unpleasant scent, then to experience a slight pain from a slight burn. Thus, scientists managed to understand the characteristics of a particular person's reaction to unpleasant physical sensations. After that, the participants were asked to read the famous "trolley problem": the essence of its description is the ability to sacrifice one person in order to save several people. This dilemma is usually controversial. On the one hand, it is wrong to say that one person is of less value than, for example, five or six people. However, leaving one and losing several victims is also immoral, so choosing the right answer is very difficult, and is there any?

In the course of the study, it turned out that after familiarization with the dilemma, the participants showed an increase in sensitivity to unpleasant odors, with a relative stability of pain sensitivity. Similar results were observed for the indications of brain activity, which was assessed using a functional type of magnetic resonance imaging . As the scientists explain, the sensations of pain and the feeling of olfactory disgust stimulate similar brain regions, which are quite difficult to separate from each other for MRI. However, experts were able to do this and, based on the indicators of brain activity, considered that it was the feeling of disgust that intensified with moral condemnation. Therefore, we can safely say about bad deeds that they smell bad, but are not physically painful. True, it is necessary to clarify that we are not talking about an obvious smell: it is, rather, a metaphor, because there are always several smells around a person at the same time, and not all of them are pleasant. However, we begin to feel the unwanted aroma much more sharply after falling into moral indignation.

The emergence of a relationship between disgust and condemnation of the moral side of the issue can be traced using the theory of evolution. Bad scent, along with disgust, signal any danger, possible harm. Anything that smells bad can be poisonous, tainted, contagious, and inherently unacceptable. And with the development of socialization, generally accepted moral criteria were formed.

Those who dare to violate the general criteria of morality put the whole group of society at risk, which provokes condemnation. At the same time, the brain does not rebuild or transform, but uses a long-existing neural response - like olfactory disgust.

The work of scientists is presented on the www.advances.sciencemag.org