A smile can brighten your mood, researchers say

A smile can brighten your mood, researchers say

When we are happy, we smile. The corners of our mouth move outward and upward, our cheeks rise, and the skin around our eyes wrinkles. But does it also work the other way around? Can smiling from our muscles improve 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 facial feedback hypothesis. In a recent paper published in Nature Human Behavior, an international collaboration of researchers led by Stanford researcher Nicholas Coles found strong evidence that posed smiles can actually make us happier.

The effect isn't strong enough to overcome something like depression, Coles said, but it offers useful insights into what emotions are and where they come from.

We experience emotions so often that we forget to marvel at how incredible this ability is. But without emotions there is no pain or pleasure, no suffering or bliss, no tragedy or glory in human existence. This research tells us something fundamentally important about how this emotional experience works.”

Nicholas Coles, Stanford research scientist

Psychologists still aren't sure where this central part of the human condition comes from. 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, for example, produces part of the sensation we call fear. 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 considered himself a breeder in this matter. There was groundbreaking facial feedback research that suggested that participants found Gary Larson's "The Far Side" comics funnier when they held a pen or pencil between their teeth without their lips touching it (which supposedly activated the same muscles as smiling). But in 2016, 17 different labs tried and failed to reproduce these results, casting doubt on the hypothesis.

When Coles conducted a meta-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 of facial feedback. So he decided to settle the matter in a way that would convince both skeptics and believers. He organized the Many Smiles Collaboration, a group that included people on both sides of the issue as well as those on the fence like Coles, and together they developed a methodology that everyone was happy with.

"Instead of arguing and debating on Twitter and in magazine articles, which would take decades and probably wouldn't be as productive, we said, 'Let's just get together and design something that both sides would like,'" Coles said. “Let’s find a way to potentially convince proponents that the effect isn’t real and potentially convince critics that the effect is real.”

The researchers created a plan that included three well-known techniques designed to encourage participants to activate their smiling muscles. A third of the participants were instructed to use the pen-in-the-mouth method, a third were asked to imitate the facial expressions seen in photos of smiling actors, and the final third were instructed to move the corners of their lips toward their ears and lift their cheeks using only the muscles in their face.

In each group, half of the participants completed the task while looking at happy pictures of puppies, kittens, flowers, and fireworks, and the other half simply saw a blank screen. They also saw these types of images (or lack thereof) while being instructed to use neutral facial expressions.

To disguise the goal of the experiment, the researchers added several other small physical tasks and asked participants to solve simple math problems. After each task, participants rated how happy they felt.

The Many Smiles Collaboration collected data from 3,878 participants from 19 countries. After analyzing their data, the researchers found that participants' happiness increased noticeably when they imitated smiling photos or pulled their mouths toward their ears. But similar to the 2016 group, they didn't see a strong change in mood among participants who used the pen-in-mouth technique.

“The effect was not as reliable in pen-in-mouth disease,” Coles said. "We're not sure why. Going into the study, we assumed that all three techniques produced the right muscle configuration for an expression of happiness. However, we found evidence that the pencil-in-mouth condition may not actually produce an expression." “It’s very similar to a smile.”

For example, holding the pen may require a certain amount of teeth clenching that is not normally present in a real smile, which could be a confounding factor. 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 length of a smile can make people happy and the furrowed brow can make people angry; therefore the conscious experience of emotions must be based at least in part on physical sensations," Coles said. "In recent years, science has taken a step back and a few steps forward. But now we are closer than ever to understanding a fundamental part of the human condition: emotions."

Source:

Stanford University

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