Researchers found smiling can reduce stress levels and lower the heart rate while performing difficult tasks.

Writing in Psychological Science, the authors tell how they studied the effects of different types of smiling in difficult situations.

Tara Kraft, of the University of Kansas, said: “Age old adages, such as ‘grin and bear it’ suggest that smiling is an important nonverbal indicator of happiness. Those who smiled after stressful tasks showed a decline in heart rate and faster recovery from stress.”

I call it “smile therapy”,