What’s in a Smile?

There are three primary types of smiles: the affiliative smile, the enjoyment smile, and the dominance smile.

The affiliative smile involves a simultaneous raising of the corners of the mouth with the formation of crow’s feet around the eyes. The enjoyment smile is very close in appearance to the affiliative smile, but the trigger for this type of smile is usually spontaneous rather than voluntary. The dominance smiles (i.e, scheming, critical, proud) have a less friendly appearance as they typically do not involve the activation of the crow’s feet, rendering a much colder effect. There are various circumstances that can affect the expression and understanding of these different smile types, including cultural norms, medical illness or injury, and elective cosmetic interventions.

Studies have shown that countries with more immigration smile more. It makes sense that nonverbal communication would be of greater importance when a common verbal language cannot be relied upon. This affiliative smile is particularly useful for those who do not already have a strong social network and/or community. When people express this type of smile, they are perceived as more approachable, more genuine, and more trustworthy.

Polls taken of people from 32 countries found that emotional expressiveness was correlated with diversity. In the less culturally diverse countries, smiling individuals were rated as less honest. This may be due to the fact that in more homogeneous nations, smiling is more often used to show superiority and exert power (i.e., dominance smiles) than as a means of making a connection.

As facial plastic surgeons, we see many people with smiles that have been affected by tissue damage and/or nerve injury. For these patients, the simple act of smiling can be very elusive and even painful. Studies have shown that patients with an impaired smile are perceived as less likeable and less trustworthy, which translates into a significant disadvantage in social situations. Not only are these individuals being judged less favorably, but they are also much less likely to get a smile in return, which can have a significant impact on mental health and happiness. In order to help treat these patients, we need to help restore their ability to effectively smile to the greatest possible degree. Much effort has been placed into determining successful smile characteristics and to developing advanced surgical techniques to replicate these qualities.

While elective cosmetic interventions are inherently undertaken to improve appearance, there can be unintended effects with detrimental effects on the smile. About 1-2% of patients undergoing facelift will have permanent weakness of a branch of the facial nerve, which can significantly impact smiling. Immobility in various facial movements can also occur after neurotoxin injections (i.e., Botox, Dysport, Xeomin).

These injections are done to reduce the appearance of wrinkles by relaxing the underlying facial muscles, with one of the most common targets for these treatments being the crow’s feet. While a degree of relaxation in this area around the eyes is associated with a more rested and youthful look, excessive weakening of these muscles can result in the inability to express an affiliative (“friendly”) smile.

Smiling is a powerful gift of communication that can dramatically influence interpersonal interactions. While there are a wide range of affable and joyful smiles, there are also smile types that are less genuine in appearance. In some social circumstances and cultures, this may be the result of an intentional display of dominance. In other cases, the lack of a sociable smile may be the result of a facial deformity, medical condition, or even as a side-effect of cosmetic interventions.

Our request is that the next time you have a negative emotional response to someone’s smile, take a moment to consider their intention. If you think they may be experiencing a facial movement disorder, a genuine smile from you might be just the right medicine.