Scholars have identified three distinct types of smiles (reward, affiliation, and dominance) that serve different social functions. New research published in Cognition and Emotion found that psychopathic traits (i.e., interpersonal difficulties and rule-breaking tendencies) may influence how these three different smile types are perceived. Specifically, those higher in psychopathic traits may be less inclined to rate these smiles positively.
“First, symmetrical smiles together with raised eye brows express happiness and social approval (reward smile),” explained study author Anna L. Dapprich and colleagues. “Second, symmetrical smiles and a lowered upper lip signal the willingness to bond socially (affiliation smile). Finally, asymmetrical smiles, a wrinkled nose and a raised upper lip express dominance and superiority (dominance smile).”
Importantly, characteristics of the perceiver such as psychopathic traits (i.e., lack of fear and reverence to rules) and social anxiety (i.e., high fear in social situations) can influence how positive or negative facial expressions are perceived. For example, previous research has shown that socially anxious people tend to be quick to avoid both smiling and angry faces while non-socially anxious people tend to be quick to avoid angry faces. Further, people with psychopathic traits to be relatively slow at avoiding angry faces suggesting they are not as averse to these expressions.
To assess whether psychopathic traits and social anxiety affect evaluations of the three different smile types, the researchers recruited a final sample of 122 women psychology students from Radboud University in the Netherlands. All participants viewed 80 faces each of which was depicting either of the three smile types, a neutral expression, or an angry expression. Eight white actors (4 men and 4 women) displayed the expressions. Participants then evaluated each expression on a scale of negative to positive. Participants also completed measures of social anxiety and psychopathic traits.
Initial results show that evaluations of the expressions were consistent with expectations. The smiling expressions were rated as more positively overall compared to the angry expression which was rated more negatively overall. Within the smiling expressions, reward smiles were rated more positively than both affiliation and dominance smiles. The evaluations of the affiliation and dominance smiles did not significantly differ.
Results also show that with higher levels of psychopathic traits positive evaluations of the reward and dominance smile decreased and positive evaluations of the angry expressions increased. Importantly, social anxiety was not related to evaluations of the expressions at all.
The authors do mention some limitations to this work including the use of static photos of these expressions and the inclusion of an only woman sample. Future research should expand to include more information about the context of the facial expression and a more gender diverse sample.
The study, “Evaluations of three different types of smiles in relation to social anxiety and psychopathic traits“, was authored by Anna L. Dapprich, Eva Gilboa-Schechtman, Eni S. Becker, and Mike Rinck.