Smiling speeds recovery from stress: study

Psychological scientists Tara Kraft and Sarah Pressman of the University of Kansas investigated the potential benefits of smiling by looking at how different types of smiling, and the awareness of smiling affects an individuals' ability to recover from episodes of stress.

"Age old adages, such as 'grin and bear it' have suggested smiling to be not only an important nonverbal indicator of happiness but also wishfully promotes smiling as a panacea for life's stressful events," said Kraft.

"We wanted to examine whether these adages had scientific merit, whether smiling could have real health-relevant benefits," Kraft said.

Kraft and Pressman's work is the first of its kind to experimentally manipulate the types of smiles people make in order to examine the effects of smiling on stress.

The researchers recruited 169 participants from a Midwestern university. The study involved two phases: training and testing.

During the training phase, participants were divided into three groups, and each group was trained to hold a different facial expression.

The researchers measured participants' heart rates and self-reported stress levels throughout the testing phase.

The results of the study suggest that smiling may actually influence our physical state.

Compared to participants who held neutral facial expressions, participants who were instructed to smile, and in particular those with Duchenne smiles, had lower heart rate levels after recovery from the stressful activities.

These findings show that smiling during brief stressors can help to reduce the intensity of the body's stress response, regardless of whether a person actually feels happy.

The study is published in the journal 'Psychological Science'.