A posed smile can improve your mood

The researchers created a plan that included three well-known techniques intended to encourage participants to activate their smile muscles. One-third of participants were directed to use the pen-in-mouth method, one-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 the muscles in their face.

In each group, half the participants performed the task while looking at cheerful images of puppies, kittens, flowers, and fireworks, and 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.

In order 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. 6But much like the 2016 group, they didn't find a strong mood change in participants using the pen-in-mouth technique.

Reference:

Nicholas Coles et al,JOURNAL:Nature Human Behaviour