In mind-body research, investigators have looked at the potential benefits of smiling by examining at how different types of smiling, and the awareness of smiling, affects 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 investigator Tara Kraft of the University of Kansas. “We wanted to examine whether these adages had scientific merit; whether smiling could have real health-relevant benefits.”

Smiles are generally divided into two categories: standard smiles, which use the muscles surrounding the mouth, and genuine or Duchenne smiles, which engage the muscles surrounding both the mouth and eyes, according to a university press release.

“Previous research shows that positive emotions can help during times of stress and that smiling can affect emotion; however, the work of Kraft and Pressman 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 press release noted.

The results of the study suggest smiling may 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.

The study will be published in Psychological Science, a journal of the Association for Psychological Science.

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