Facial Mimicry in Unstructured Dyadic Interactions: A Cross-Cultural Study

Facial mimicry, known as the tendency to imitate other individuals' facial muscular movements, is key to establishing successful interpersonal relationships. Studies on various cultures have confirmed this tendency, suggesting that facial mimicry is a universal behavioral pattern in interpersonal communication. However, its cross-cultural variability is expected because of the influence of cultural norms regarding facial expressions. By focusing on unstructured dyadic interactions, we addressed the unexplored cross-cultural variability of facial mimicry through a secondary analysis of video data obtained in Japan and Spain and a further analysis of newly collected videos in Taiwan. We also explored the association between the Big Five personality traits and facial mimicry cross-culturally. To measure facial mimicry, the intensity of each facial action unit movement was quantified using OpenFace, which underwent multidimensional dynamic time warping. First, employing the pseudo-synchrony paradigm of random data shuffling, we confirmed that interactants displayed facial mimicry beyond chance during their conversation. Second, we found that the extent of mimicry was significantly different among the three cultures; that is, interactants from East Asian cultures (Taiwan, Japan) showed a greater extent of mimicry than those from Western cultures (Spain) even after controlling for unbalanced gender composition in the data. Third, conscientiousness was significantly associated with the degree of mimicry. However, the association between personality traits and mimicry was not consistent across cultures. Overall, this study discusses the importance of cross-cultural research in facial mimicry, as in the study of facial expressions.