Scientists from Stanford University have found that even a fake smile can make a smiling person happier. The study is published in Nature Human Behavior .
Almost four thousand people from 19 countries took part in the experiments. One-third of the participants were asked to simply hold a pencil in their mouth (this creates a semblance of a smile), one-third were asked to imitate the facial expressions of smiling actors, and the rest were asked to raise the corners of their lips. To hide the purpose of the test, the researchers asked the participants to solve simple math problems and rate their level of happiness after each task.
The researchers found a marked increase in happiness in participants who imitated smiling photographs or drew their mouths to their ears. As in previous work, they found no strong mood changes in participants who simply held a pencil in their mouth.
The observed effect is not enough to overcome depression, for example, but the study provides useful information about the nature of emotions. The work showed that just as positive emotions can cause muscle movement (smiling), muscle movement can improve mood.