Consensual and idiosyncratic trustworthiness perceptions independently influence social decision-making

Trustworthiness perceptions are based on facial features that are seen as trustworthy by most people (e.g., resemblance to a smile) and features that are only seen as trustworthy by a specific perceiver (e.g., resemblance to a loved one). In other words, trustworthiness perceptions reflect consensual and idiosyncratic judgment components. Yet, when examining the influence of facial cues on social decision-making previous studies have almost exclusively focused on consensual judgments, ignoring the potential role of idiosyncratic judgments. Results of two studies, with 491 participants making 15,656 trust decisions, showed that consensual and idiosyncratic trustworthiness judgments independently influenced participants’ likelihood to trust an interaction partner, with no significant differences in the magnitude of the effects. These results highlight the need to consider both consensual and idiosyncratic judgments. Previous work, which only focused on the effect of consensual judgments, may have underestimated the overall influence of trustworthiness perceptions on social decision-making.