Biracial Faces Offer Visual Cues of Successful Intergroup Contact: Genetic Admixture and Coalition Detection

This research explores how biracial facial cues affect racial perception and social judgment. We tested a coalition-signaling hypothesis of biracial cues in two studies conducted in the United States (n = 227) and China (n = 116). From the perspective of intergroup and interpersonal relations theories in social psychology, biracial features would likely be perceived as cues of threat or resource competition. In contrast, we propose an evolutionary hypothesis that biracial facial cues reveal the ancestral history of intergroup alliances between members of two races or ethnic groups. When racial cues are mixed, we predict that biracial individuals may be viewed more positively than other-race or even own-race members who often compete for limited ingroup resources. The participants observed facial images that ranged from 100% Asian to 100% Caucasian, including morphed biracial composites of 30%, 40%, 50%, 60%, and 70% Caucasian or Asian. The participants evaluated each image regarding perceived Caucasianness (Asianness), attractiveness, trustworthiness, health, intelligence, and career prospects. The US and Chinese samples yielded a similar pattern of own-race bias in racial perception and biracial favoritism in social judgment. The social judgment ratings were not correlated with the racial perception scores and were independent of the sex of the participants or biracial images, indicating a coalitional motive, instead of a mating motive, underlying social perception of biracial individuals. Overall, the results suggest that biracial facial features signal a successful genetic admixture and coalition in parental generations and thus increase the trustworthiness and cooperative potential of a biracial person.