Abstract
Introduction. Mixed-race face categorization has become a new challenge for children and adults across the globe. Most of this work has focused on biracial Black/White stimuli with Caucasian participants, and the role of skin color remains unclear. Here we investigated the effect of skin color on race categorization spanning the Asian-Black and the Asian-White morphing face continuum in Taiwanese children and adults. Methods. Sixty-six Taiwanese children (4- to 14-year-olds, 31 boys) and 40 adults (19- to 42-year-olds, 20 males) completed the experiment. We adopted a novel 3AFC (Asian, White/Black, or biracial) paradigm to assess participants’ categorization decisions on four stimulus sets of morphed images of Asian-White and Asian-Black faces (A0= 0% Asian component, A100= 100% Asian Face) in both grayscale and color. Results. Overall, the probability of judging “Asian” increased as the Asian component increased for the grayscale and color conditions in all age groups. For the Asian-White face continuum, children and adults tended to classify the A50/A60 faces as white and A70 as Asian. Notably, compared with the grayscale condition, the color condition elicited more “Biracial” responses for the A40 to A70 faces, particularly in children under 7. For the Asian-Black continuum, adults and children responded more accurately that they consistently judged the A50 faces as biracial. Adding skin color did not change the categorization responses. Conclusion. Our findings suggest that the physiognomy cue alone (i.e., the grayscale condition) is sufficient for older children and adults to make proper racial categorizations. Nevertheless, skin color cue enhances perceptual richness that helps people of all age (more pronoucedly for young children), attribute morphed faces to the corresponding side of the Asian-White racial continuum and accurately classify the faces as biracial. Notably, the influence of skin color is less prominent in the Asian-Black racial continuum.