Trust is a foundation of interpersonal communication. Faces have a significant impact on trust judgments, and separate research demonstrates that group membership also influences trust judgments. However, it remains unclear whether and how group membership moderates the effect of face trustworthiness on trust judgments and investment decisions. In the present research, two experiments were conducted to explore the moderating effect of group membership (i.e., in-group vs. out-group) on perceptions of facial trustworthiness and trust judgments. Results showed that participants invested significantly more money on trials with trustworthy faces than trials with untrustworthy faces. Additionally, there was a significant interaction between group membership and facial trustworthiness; the investment difference between trustworthy faces and untrustworthy faces was greater for trials with in-group member faces than out-group member faces. These findings indicate that top-down and bottom-up cues jointly influence behavioral decisions.
Keywords: Trust; bottom-up; facial trustworthiness; group membership; top-down.