Does smiling change how observers rate the attractiveness of people with facial paralysis?

Details

There is little data on the perception penalty associated with facial paralysis. The researchers aimed to measure society's perception of facial paralysis in terms of beauty. They hypothesized that people with facial paralysis would be considered less attractive than people without paralysis, and that smiling would amplify this difference.

In a randomized controlled experiment, 40 subjects viewed photographs of faces with and without paralysis. They rated attractiveness, identified whether paralysis was present, assessed its severity, and identified the feature most affected.

Attractiveness scores differed significantly between faces with and without paralysis (Wilcoxon rank sum test, z = 16.912; P < .001). A mixed effects regression model was used to explain differences in scores. The fixed portion of the model showed that faces with paralysis were rated 1 standard deviation less attractive than faces without paralysis. Smiling increased attractiveness ratings for faces without paralysis (constant, 5.9; smile effect, 0.735; P < .001). The smile × paralysis interaction term was -0.892 (P < .001), but it was not significantly different from the smile term (χ²(1) = 0.87; P = .352). The random effects model showed intersubject rating variability of 1.32.

The researchers concluded that facial paralysis carries a significant attractiveness penalty, with affected faces considered markedly less attractive than faces without paralysis. However, ratings did not change significantly when patients smiled, despite the increased asymmetry associated with smiling. Observers were moderately good at identifying the presence of facial paralysis, but less good at distinguishing which side was affected. The researchers stated that these findings have important implications for evidence-based counseling and management of patients with facial paralysis.