Smiling has to be a good thing and, broadly speaking, it is, but Aparna Labroo and colleagues have conducted research that shows it depends on what you are expecting.
Despite the somewhat infamous title line from Monty Python, the research examined the principle that the more people smile, the happier they will be. This concept was given weight by the work of Addelman and Zajonc (1989) where they showed that smiling, even involuntary lifting of the mouth by producing smile-like sounds, improved mood. They did not, however, show that this resolved a negative mood. It tended to lift a neutral mood. There is also some support for the idea that afferently stimulating the seventh cranial nerve by smiling (which controls muscles used for facial expressions like smiling) can stimulate elements of the social engagement system and interpersonal relating (Siegel, 2009; Porges, 2013), but is there a proviso?
Addelman and Zajonic found that if smiling was seen as a reactive or a reflection of personal happiness, then smiling was beneficial for well being. If, however, smiling was seen as proactive and causing happiness, then frequent smiling resulted in less well being. You might interpret that as showing the need for meaning and relevance for our bodies to respond in more than superficial ways. Smiling to become happy is not an effective method. Smiling when you are happy is a tonic for you and for those around you.
The counter-intuitive implication of expectation is also shown in an interesting study on the emotional consequences of using Facebook. Sagioglou & Greitemeyer (2014) wondered why so many people spent large amounts of time on Facebook, even though their research showed that it created negative mood. They first looked at the time spent of Facebook and found that the longer people are active on Facebook the more negative their mood afterwards. They then looked at the relationship of negative mood to the feeling that the user was not doing anything meaningful. This proved a strong correlation. So, if wasting time is a major creator of negative mood, why do people keep going back to using Facebook. The answer was that many users committed an ‘affective forecasting error’ – they expected to feel better.
Expectation can be a driver of motivation even when the result proves them wrong. What is surprising is that some people will persist with pushing for the expected result regardless of evidence to the contrary. Expectations can be a motivation, but they can also be the source of disappointment and dissatisfaction. The trick is to find something to smile about and then smile about it frequently, without an expectation of anything.
Addelman, P. K. & Zajonc, R. B. (1989) Facial efference and the experience of emotion Annual Review of Psychology, 40: 249-280
Labroo, A. A., Mukhopadhyay, A., & Dong, P. (2014) Not always the best medicine: Why frequent smiling can reduce wellbeing. Journal of Experimental Social Psychology, 53: 156-162
Porges, S. W. (2013) The Polyvagal Theory. New York, NY: W. W. Norton
Sagiogiou, C., & Greitemeyer, T. (2014) Facebook’s emotional consequences: Why Facebook causes decrease in mood and why people still use it. Computers in Human Behavior, 35: 359-363
Siegel, D. J. (2012) The Developing Mind (2nd Ed). New York, NY: Guilford Press