Facial coverings differentially alter valence judgments of emotional expressions

Despite benefits for reducing disease spread, masks obscure facial expressions, impairing nonverbal communication of emotion. We assessed the impact of lower (masks) and upper (sunglasses) facial coverings on valence judgments of clearly valenced (fearful, happy) and ambiguously valenced (surprised) facial expressions, the latter of which have valid positive and negative meaning. Results from an online sample (n = 146) showed that masks, but not sunglasses, impaired judgments of clearly valenced expressions compared to expressions without coverings (ps < .001). Sunglasses, but not masks, affected judgments of the ambiguous surprised expressions (p = .08). Drift diffusion models revealed that face coverings impacted the judgment process in an expression-specific manner: Masks increased the amount of evidence required to reach a judgment boundary for both fearful and surprised faces (ps < .001) by eliminating starting point bias, whereas masks slowed evidence accumulation for happy faces (p < .001). Political ideology interacted with these effects, such that we observed stronger negativity bias towards masked expressions for Republican- than Democrat-leaning participants, particularly for happy faces (p < .001). In short, our results replicate interference effects of face coverings in the decoding of emotional expressions and suggest that political beliefs alter the degree of this interference. The findings have implications for nonverbal communication of emotion and intergroup communication.