Negative aftereffects of face trait impressions are modulated by emotional expressions

Facial trustworthiness impressions critically shape our everyday social interactions. While previous research has predominantly considered trustworthiness impressions to be stable over time, preliminary evidence has shown that they are affected by visual adaptation, such that long exposure to (un)trustworthy-looking faces biases the perception of following faces in the opposite trustworthiness direction. Here, by employing a visual adaptation task across two experiments, we sought further evidence that trustworthiness impressions are shaped by the temporal context. In Experiment 1, we investigated whether visual adaptation affect trustworthiness judgements and found evidence of robust negative face aftereffect. In Experiment 2, we focused our investigation on whether emotional expressions, key cues involved in trait impressions, influence trustworthiness and dominance impressions. We found that adaptation to anti-expressions, which were expected to bias subsequent neutral faces to resemble the original expression (happiness, anger, and fear), significantly modulated subsequent evaluations of trustworthiness and dominance. This result confirms the critical role of emotion perception in trait evaluations. Importantly, using anti-expressions minimised semantic adaptation, thus highlighting the perceptual nature of this aftereffect. Taken together, our findings confirm that temporal context shapes trustworthiness impressions, by showing that visual adaptation affects trust judgements, and that past emotional expressions influence following impressions of trustworthiness and dominance.