Interaction of stereotypical trustworthiness, facial resemblance, and group membership in the perception of trustworthiness and other traits

Trust begins with our first impression of others. But which matters most in forming the first impression that others possess stereotypically trustworthy facial features, that they look like us, or that they belong to our social group? This study explored the interaction among stereotypical trustworthiness, kinship (based on facial resemblance), and group membership (using arbitrary groups) in the formation of first impressions. Each participant rated 48 stimuli varying in stereotypical trustworthiness (trustworthy vs. untrustworthy), facial resemblance (self vs. other), and group membership (ingroup vs. outgroup) on three traits (trustworthiness, competence, and attractiveness). We observed unique interaction patterns for each of the three traits and we speculate that there is a match between the primacy of the information and the primacy of the evaluated dimension that influences the formation of first impressions. In addition, we propose that group membership may drive first impressions in the absence of kinship information. Our integrative approach brings us closer to understanding the formation of first impressions, and thus trustworthiness and trust, in real-life situations. Our findings outline stimulating directions for further research.