The social ecology of trustworthiness inferences: Cultural gradients in emotion overgeneralization

Judgments of trustworthiness from faces guide critical social decisions. It remains debated whether these judgments reflect shared features of human perception or are shaped by cultural experience. One prominent explanation is emotion overgeneralization: faces that structurally resemble emotional expressions elicit corresponding impressions, even when no emotion is displayed. Although often treated as universal, emotion overgeneralization may reflect ecological learning shaped by culture-specific norms. We propose a cultural gradient: where emotional expressions are more informative, the link between happiness resemblance and perceived trustworthiness should be stronger. Participants from 32 countries (N ≈ 6,400) will evaluate the trustworthiness of unfamiliar individuals from standardized resting facial photographs and complete a measure of emotional expressivity, with each face’s resemblance to happiness quantified computationally. We will test whether emotional expressivity is associated with greater emotion overgeneralization at both country and individual levels. Null results would favor perceptual invariance, whereas positive associations would support ecological calibration.