By John Salak –
The smallest smile—even an unintentional slight grin—matters to how a person is perceived. Even a brief weak grin for a second makes faces appear more joyful, making it more likely for others to see happiness in expressionless faces.
This realization stems from University of Essex research that relied on a pioneering experiment involving electrical stimulation to spark smiles—an approach that was inspired by photographs made famous by Charles Darwin.
The results may yield more than a nebulous feel-good impact. They may help generate potential treatments for depression or disorders that affect expression, like Parkinson’s and autism, according to study leader Dr Sebastian Korb.
“The finding that a controlled, brief and weak activation of facial muscles can create the illusion of happiness in an otherwise neutral or even slightly sad-looking face, is ground-breaking,’ he reported. “It is relevant for theoretical debates about the role of facial feedback in emotion perception and has potential for future clinical applications.”
The Essex team reports its work is the first time facial electrical stimulation has been shown to affect emotional perception. The technique itself, however, dates back more than a century and stems from a process developed in the 19th century by the French physician Duchenne de Boulogne. Darwin, in turn, published drawings of Duchenne’s work in The Expression of the Emotions in Man and Animals.
The British researchers admitted they dialed down the voltage in their work to ensure the safety of the study’s 47 participants. By using computers, the team was also able to control the onset of smiles with millisecond precision.
Ultimately, the study found that producing a weak smile for just 500 milliseconds was enough to induce the perception of happiness.
More smiles may be coming soon with good reason.
“In the future, however, we hope to apply this technique to explore facial emotion recognition, for people with conditions like Parkinson’s, who are known to have reduced spontaneous facial mimicry and impaired facial emotion recognition,” Korb said. “Moreover, we have published guidelines to allow other researchers to safely start using electrical facial muscle stimulation.”
