The grosser someone sounds when they cough or sneeze, the more likely you are to suspect they have a contagious infection — even if it’s not true.
That’s the upshot of a new study in which participants were asked to judge whether people were — or weren’t — infected with a communicable disease by the sound of their coughs and sneezes.
On average, they guessed about four out of 10 sounds correctly, according to researchers at the University of Michigan in Ann Arbor. The findings were recently published in the journal Proceedings of the Royal Society B: Biological Sciences.
“We find no evidence that perceivers can reliably detect pathogen threats from cough and sneeze sounds, even though they are reasonably certain they can,” said study lead author Nicholas Michalak, a doctoral student in psychology.
“Moreover, there was no evidence that accuracy improved when participants knew the true number of infectious sounds in advance or when participants focused on how clear or disgusting they perceived the sounds,” he added in a university news release.
Michalak said it appears that people are convinced that sounds that disgust them represent a likely disease threat. And that could lead them to shun others who make disgusting but noninfectious noises, he noted.
The study authors said the findings suggest that when you hear someone cough or sneeze, it might be best to leave the diagnosis to the doctor.
The U.S. Centers for Disease Control and Prevention outlines coughing and sneezing etiquette.