A smile is supposed to always be a sign of good news, but that may be biased towards the person doing the smiling. A big grin communicates a smiler’s happiness, boosts their mood and may convince them of other people’s happiness as well. On the other hand, while nobody wants to be scowled at, it turns out that people don’t always find it pleasant to be on the receiving end of a happy face. Depending on context, someone else’s smile can even be a source of stress.
Aside from the uncontrollable grin you have in response to personal enjoyment, there are three major types of social smiles. These smiles may be tied to a person’s impression of an event, but are largely meant to communicate a message to another individual. As their name indicates, rewarding smiles are meant to provide positive feedback to someone, encouraging their activity. Affiliation smiles are meant to build relationships, or at least show an attempt to relate to another individual. Dominant smiles are the least friendly of the three, as they’re sort of a passive aggressive way to remind someone of the smiler’s social superiority.
How friendly are those faces?
It’s not hard to imagine which of these smiles is the most pleasant to receive, but researchers needed to quantify the effects of these social interactions before they could draw conclusions about how they work. As a test, volunteers were asked to give a short speech, then shown reactions from “judges” via video. Judges were actually prerecorded, and were really just there to flash different types of smiles to the test participants so that their levels of the stress hormone cortisol could be measured. In every case, cortisol levels went up in the test participants, even when seeing a rewarding smile. However, the dominant smile triggered the biggest response, raising cortisol levels three-times higher than other facial expressions.
The fact that a dominant smile was unconsciously perceived as slightly threatening may not be surprising. There was an odd twist with test participants that suffered from social anxiety disorders or depression though. The type of smile didn’t seem to make much of a difference to these people one way or the other. Being less responsive to unwanted dominant smiles may sound like a benefit, but this suggests that these emotional disorders may limit people’s responsiveness to any social signals.
Source: The condescending smiles of others stress us out by Kimberly Hickok, Science