When we are happy, we smile. The corners of the mouth turn out and up, the cheeks are raised, and the skin around the eyes wrinkles. But does it work the other way around? Can the posture of our muscles in a smile brighten our mood?
This question is part of a long-standing debate among psychology researchers about whether facial expressions influence our emotional experience, an idea known as the so-called ‘facial feedback hypothesis’. In an article published this Thursday in the magazine Nature Human Behavioran international group of researchers led by Stanford scientist Nicholas Coles has found strong evidence that fake smiles can help us feel happier.
The effect isn’t strong enough to overcome something like depression, but it does provide useful insight into what emotions are and where they come from, the author says in a Stanford University news release.
“We experience emotions so often that we forget to marvel at how incredible this ability is. But without emotion, there is no pain or pleasure, no suffering or happiness, no tragedy or glory in the human condition,” he adds. “This research tells us something important about how this emotional experience works.”
Psychologists are still unsure of the origins of this essential component of the human condition. One theory is that our conscious experience of emotions is based on sensations in the body: the idea that the sensation of a rapid heartbeat provides part of the sensation we describe as fear, for example. Facial feedback has often been cited as evidence for this theory, but some recent experiments have called it into question.
bite a pen
Before completing this project, Coles was looking at this issue from the sidelines. There had been pioneering research on facial feedback suggesting that participants found Gary Larson comics more amusing when they read them while holding a pen or pencil between their teeth (supposedly activating the same muscles as a smile). But in 2016, 17 different labs tried to replicate these results and failed, casting doubt on the hypothesis.
When Coles conducted an analysis of previous studies on the topic in 2019, which included a variety of different methods, his results seemed to indicate that there was at least some evidence supporting facial feedback. So she decided to try to settle the matter in a way that would convince both skeptics and believers. She organized the ‘Many Smiles Collaboration’ project.
“Instead of arguing and debating on Twitter and in magazine articles, which would take decades and probably not be as productive, we said, ‘Let’s get together and design something that satisfies both parties,’” Coles said. “We’re going to come up with a way that we can potentially convince advocates that the effect isn’t real, and potentially convince critics that the effect is real.”
Three techniques to smile
The researchers created a plan that included three well-known techniques designed to encourage participants to activate their smile muscles. One-third of the participants were instructed to use the pen-to-mouth method, one-third were asked to mimic facial expressions seen in photos of smiling actors, and the final third were instructed to move the corners of the lips towards the ears and lift the cheeks using only the muscles of the face.
In each group, half of the participants performed the task while viewing cheerful images of puppies, kittens, flowers and fireworks, and the other half simply viewed a blank screen. They also saw these same types of images (or lack thereof) while being instructed to use a neutral facial expression.
To disguise the objective of the test, the researchers mixed other small physical tasks and asked the participants to solve simple mathematical problems. After each task, participants rated their level of joy.
The project collected data from 3,878 participants from 19 countries. After analyzing their results, the researchers found a marked increase in feelings of joy in participants who imitated smiling photos or pulled the corners of their mouths toward their ears. However, similar to the 2016 group, they found no major mood change in participants who used the pen-to-mouth technique.
The stretching of a smile can make people feel happy and a frown can make people feel angry.
— Principal investigator
“We do not know why. At the start of the study, we assumed that all three techniques created the correct muscle configuration for an expression of happiness. But we found some evidence that the pen-to-mouth technique may not create an expression that truly resembles a smile,” Coles says in the press release.
For example, the act of holding the pen may require some degree of teeth pressure that is not usually present in a genuine smile, which could be a confounding factor. However, the evidence for the other two techniques is clear and provides a convincing argument, according to the researchers, that human emotions are somehow linked to muscle movements or other physical sensations.
“The stretching of a smile can make people feel happy and a frown can make people feel angry; therefore, the conscious experience of emotion must be based, at least partially, on bodily sensations”, says Coles. “In recent years, science has taken a step back and another step forward. But now we are closer than ever to understanding a fundamental part of the human condition: emotions.”