Facial trustworthiness predicts ingroup inclusion decisions

Perceivers tend to be reluctant to admit new members into their ingroups—unless there is some potential for prospective group members to provide value to the group. In the present research, we examine the effect of facial trustworthiness on ingroup inclusion decisions. Five studies demonstrate that facial trustworthiness exerts a powerful bottom-up perceptual cue that conveys this necessary “positive information,” resulting in an increased likelihood of ingroup acceptance. This effect was first found for a homogenous sample of White male faces (Study 1), but was also found independent of sex (Study 2), and independent of race (Studies 3a, 3b, & 4), whereby facial trustworthiness influenced inclusion decisions more than salient aspects of group membership (i.e., sex and race).