Some of the earliest work in the area was done by psychologist and "facial coding" expert Paul Ekman. While experimenting with negative facial expressions like frowns, Ekman found that his mood seemed to be altered. In 1990, Ekman's research on other subjects showed that adopting a "Duchenne smile" - a full smile that involves facial muscles around the eyes - produced a change in brain activity that corresponded with a happier mood.
Chopsticks, Anyone?
A few months ago, new research was published in Psychological Science by Kansas researchers Tara Kraft and Sarah Pressman. They used a rather unusual way of getting their subjects to simulate different smiles: the subjects held chopsticks in their mouth in different configurations to form smiles and neutral expressions. While this seems awkward, it's a good way to demonstrate if facial muscle activity can affect mood.
Some subjects assumed a Duchenne smile as described above; others, a "social smile" that involved only the mouth. "Smilers" exhibited lower heart rate levels after completing a stressful task compared to subjects who assumed a neutral expression. Some of the forced smilers received an instruction to smile along with the chopsticks; they showed even less stress than those who got no instruction. The Duchenne smilers had lower stress numbers than the social smilers, though the data was insufficient to draw a conclusion.
Botox Levels More Than Wrinkles
As further evidence of the reverse linkage between facial muscles and emotions, Botox injections have been shown to dampen emotional responses. These injections paralyze small, wrinkle-causing muscles around the eyes. That makes the face look smoother, but it also smooths out emotions to a small extent. Scientists report both a reduction in depression symptoms as well as weaker reactions to "happy" video clips. This effect doesn't appear to be enormous - Botox won't turn people into walking automatons. But, a variety of research shows a measurable effect on one's emotional experience.
Fake It!
Decades of research bear out the basic truth: your mood is elevated and your stress is reduced if you plaster a big smile on your face, even for a short period of time. (Frowns have been shown to have the opposite effect.) The smile doesn't have to be based on real emotion - faking it works. And while the research details vary, I'd recommend going with a full, true smile that involves your eyes as well as your mouth. That's almost certainly a more potent mood changer.
Mood Contagion
And, there's another benefit to that Duchenne smile: if you do it in public, those around you will be lifted as well. As the WSJ's Sumatha Reddy reminds us, UCLA scientist Marco Iacoboni notes that our brains are wired for sociability. In particular, if one person observes another person smile, mirror neurons in that person's brain will light up as if he were smiling himself. So, smile in private if you must, it will still boost YOUR mood... but why not extend that benefit to those around you by smiling in public?
Roger Dooley is the author of Brainfluence: 100 Ways to Persuade and Convince Consumers with Neuromarketing (Wiley, 2011). Find Roger on Twitter as @rogerdooley and at his website, Neuromarketing.
