Forcing a smile during a stressful situation may seem unhealthy (isn't it bad to repress our emotions?) but research suggests that faking happiness is a reliable coping mechanism with physiological effects.
As part of a study published in the journal Psychological Science researchers at the University of Kansas had subjects perform stressful acts—tracing a star with their non-dominant hands by looking at a reflection of the star in a mirror, and submerging a hand in ice water—while holding various facial expressions. The facial expressions they were told to hold were a neutral face, a "standard" smile which engages just the muscles around the mouth, and a "Duchenne" smile, which uses the muscles around the eyes as well (a standard smile is more like a "say cheese" grin, while a Duchenne smile is the spontaneous kind).
The participants who smiled during the stressful activities, and especially those who held the Duchenne smiles, had lower heart rates after the stressful activities than did the people who maintained neutral facial expressions, indicating that smiling dampened the body's stress response.
It's fascinating to me that the physical act of smiling, even if you don't feel happy, is a reliable coping mechanism that can actually have a positive impact on our bodies. While it's often not easy to adjust your attitude or see the bright side of a situation, it's dead easy to scrunch your face into a fake smile.
"The next time you are stuck in traffic or are experiencing some other type of stress you might try to hold your face in a smile for a moment," says study co-author Sarah Pressman, in a statement. "Not only will it help you 'grin and bear it' psychologically, but it might actually help your heart health as well!"