Gaze allocation and evaluations of dynamic smiles following angry versus neutral expressions

This study investigated how people perceive smiles that follow an angry versus a neutral expression by examining gaze patterns and subjective evaluations when presented with dynamic facial expressions. In an eye-tracking experiment, participants viewed morph movie stimuli in which facial expressions changed either from anger to a smile (anger-to-smile condition) or from a neutral expression to a smile (neutral-to-smile condition), while their gaze allocation to different facial parts (eyes, nose, mouth) was recorded. Then participants evaluated the sincerity of the final smiles and how happy and angry the poser appeared to feel. Results revealed that ratings of sincerity, happiness and anger for the final smiles did not differ between conditions, whereas gaze allocation did. Participants in the anger-to-smile condition fixated longer to the eyes; however, fixations to the eye regions did not reliably predict subjective ratings. Contrary to our predictions, longer fixation on the mouth were associated with higher ratings of sincerity and happiness regardless of conditions and with lower ratings of anger in the anger-to-smile condition. Time-course analyses for gaze distribution over time indicated that gaze shifted from the nose toward the eyes and mouth over time and exploratory analyses also showed that the temporal changes in the gaze distribution in later phases of morphing changes were associated with subjective ratings. However, these associations did not reliably differ by preceding emotional contexts. These findings suggest that, when viewing dynamic smiles embedded in a prior negative context, attention to the smiling mouth is linked to more positive evaluations, potentially reducing sensitivity to earlier negative emotional cues. In the present paradigm, the preceding facial expression did not produce detectable differences in explicit evaluations; whether such temporal information contributes to authenticity inferences remains to be tested directly. Future research should examine this question using explicit authenticity judgments and richer social-context cues that motivate masking.