As a well-known song from Annie reminds us, “You’re never fully dressed without a smile.” Sure, it might be more problematic to go out in public without pants than it would be to go without a smile, but remembering to wear a smile is still beneficial. The simple act of smiling has an amazing ability to inspire happiness.
Studies show that smiling may actually generate positive emotional experiences.
The idea that facial expressions contribute to emotional states, rather than simply reflecting them, can be found as far back as the work of Charles Darwin. For many years, researchers have been performing experiments aimed at studying the effects of smiling on the experience of happiness.
These researchers have used a variety of methods to mimic the physical act of smiling (eliminating happiness as a precursor), which has enabled them to study the expression itself as a cause of emotion. Repeatedly, results have indicated that arranging the facial muscles into a smile can actually produce positive emotions.
A study conducted by Robert Zajonc, Sheila Murphy, and Marita Inglehart even found a possible reason for this phenomenon. According to their research, the muscular movements associated with smiling cool the blood flowing to the brain through particular veins. This leads to fluctuations in brain temperature, which causes the release/blockage of emotion-related neurotransmitters (the chemicals cells use to communicate).
If these studies are correct, smiling might just be the quickest and easiest way to feel happier.
Smiling also creates a happiness-inducing environment.
People generally respond more favorably to those they perceive as friendly. When we smile, we become more approachable (and often more attractive) to others. This is likely to improve our existing relationships, as well as increasing the likelihood that we will form rewarding new connections.
A smile can also improve the moods of those around us. Think about the difference between waiting in a line of happy people having animated conversations or waiting in a line of irate customers yelling at the cashier for going too slow. It might take the same amount of time to reach the front of those two lines, but it’s pretty clear which line will leave us feeling better. Smiling helps build a positive atmosphere, which can lead to a happier experience for everyone involved.
Of course, that isn’t to say we should force ourselves to smile all the time. If we are unhappy, it is perfectly okay to feel and process those emotions, rather than hide behind a mask of happiness. But on those occasions where we find ourselves making a “neutral” face, it might be worth showing off those pearly whites (or lack thereof), instead.
 Zajonc, R.B., Murphy, S.T., & Inglehart, M. (1989). Feeling and facial efference: Implications of the vascular theory of emotion. Psychological Review 96(3), 395-416.