It’s natural to smile when you’re happy. But if you force your face to smile – moving the corners of your mouth out and up, lifting your cheeks and crinkling the skin around your eyes – it can actually brighten your mood.
So claims a very large collaboration of researchers in the US, Israel, Europe, Australia, South America and Africa headed by social psychologist Dr. Nicholas Coles, director of the psychological science accelerator at Stanford University. The Israeli who participated was Dr. Niv Reggev, head of the Society, Cognition, Motivation and Brain Lab at Ben-Gurion University of the Negev (BGU) in Beersheba.
This question has been part of a long-standing debate among psychology researchers about whether facial expressions influence our emotional experience, an idea known as the facial feedback hypothesis. The team has just published its findings in the prestigious journal Nature Human Behavior under the title “A Multi-Lab Test of the Facial Feedback Hypothesis by the Many Smiles Collaboration.”
The beneficial effect isn’t strong enough to overcome a condition like depression, declared Coles, “but it provides useful insight into what emotions are and where they come from. We experience emotion so often that we forget to marvel at just how incredible this ability is. But without emotion, there’s no pain or pleasure, no suffering or bliss and no tragedy and glory in the human condition,” he said.
“This research tells us something fundamentally important about how this emotional experience works.”
How does this phenomenon happen?
“Rather than quibble and debate over Twitter and through journal articles that would take decades and probably not be very productive, we said, ‘Let’s just come together and design something that would please both sides.’”
Dr. Nicholas Coles, Stanford University
Psychologists still aren’t sure about the origins of this major part of the human condition. One theory is that our conscious experience of emotions is based on sensations in the body – the idea that the feeling of a rapid heartbeat provides some 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.
Before completing this project, Coles regarded himself as “sitting on the fence” regarding the issue. There had been key facial feedback research suggesting that participants found Gary Larson’s The Far Side comics funnier when they held a pen or pencil in their teeth without letting their lips touch it – supposedly activating the same muscles as a smile. But in 2016, seventeen different labs tried and failed to replicate these results, casting the hypothesis into doubt.
When Coles conducted previous studies on the subject in 2019 that included a variety of different methods, his results seemed to indicate there was at least some evidence supporting facial feedback. He decided to try to settle the matter in a way that would persuade both skeptics and believers by organizing the Many Smiles Collaboration, which included people on both sides of the issue as well as fence-sitters like himself. Together, they devised a methodology that satisfied everyone on the team.
“Rather than quibble and debate over Twitter and through journal articles that would take decades and probably not be very productive, we said, ‘Let’s just come together and design something that would please both sides,’” Coles recalled. “Let’s figure out a way to potentially persuade proponents that the effect isn’t real and potentially convince critics that the effect is real.”
The researchers prepared a plan that included three well-known techniques intended to encourage participants to activate their smile muscles. A third of participants were directed to use the pen-in-mouth method; another third were asked to mimic the facial expressions seen in photos of smiling actors; and the final third were given instructions to move the corners of their lips toward their ears and lift their cheeks using only their facial muscles.
In each group, half the participants performed the task while looking at cheerful images of puppies, kittens, flowers and fireworks, while the other half simply saw a blank screen. They also saw these same types of images or lack thereof while directed to use a neutral facial expression.
To disguise the goal of the trial, the researchers mixed in several other small physical tasks and asked participants to solve simple math problems. After each task, participants rated how happy they were feeling.
The Many Smiles Collaboration collected data from 3,878 participants from 19 countries. After analyzing their data, the researchers found a noticeable increase in happiness from participants mimicking smiling photographs or pulling their mouth toward their ears. But much like the 2016 group, they didn’t find a strong mood change in participants using the pen-in-mouth technique.
“The effect wasn’t as reliable with the pen-in-mouth condition,” Coles noted. “We’re not sure why. Going into the study, we assumed that all three techniques created the correct muscular configuration for an expression of happiness, but we found some evidence that the pen-in-mouth condition may not be actually creating an expression that closely resembles smiling.”
For instance, the act of holding the pen may require some amount of teeth-clenching that isn’t usually present in a genuine smile, which could be a confounding factor, the researchers suggested. Nonetheless, the evidence from the other two techniques is clear and provides a compelling argument that human emotions are somehow linked to muscle movements or other physical sensations.
“The stretch of a smile can make people feel happy and the furrowed brow can make people feel angry; thus, the conscious experience of emotion must be at least partially based on bodily sensations,” Coles said. “Over the past few years, the science took one step back and a few steps forward. But now we’re closer than ever to understanding emotion – a fundamental part of the human condition.”