Those who wrinkle their eyes while they smile or frown appear more sincere, new research suggests.
Researchers at the Western University in Canada showed participants photos of people smiling and frowning with and without eye wrinkles, a feature known as “the Duchenne marker”.
Participants alternated between the two images before eventually focusing on the image they perceived more relevant.
Dr Julio Martinez-Trujillo, the study’s principal investigator, said “the expressions involving the Duchenne marker were always dominant”.
“So if the emotion is more intense, your brain actually prefers to bring it into perceptual awareness for longer time,” he said.
“When you have social interactions you need to perceive whether a person is sincere or not. So my interest now is what will be the results if we do this same test with people with autism spectrum disorder.
“They often have trouble reading out emotions from other people, so we wonder if that might have to do with their ability to read this marker for sincerity.”
Nour Malek, first author on the paper, said “these findings provide evidence of a potential universal language for reading emotions”.
“In other words, a given facial action may have a single role across multiple facial expressions - especially if that facial action shapes your social interactions,” he said.
“For example, knowing if a stranger’s smile is genuine and whether that person can be trusted, warns you whether you should evade or not.”
The study was conducted in collaboration with the University of Miami and was published in the American Psychological Association journal Emotion.