Looking smart: Preschoolers' judgements about knowledge based on facial appearance

Preschoolers use others' behaviours to make inferences about what traits they possess (Harris et al., 2018, Ann. Rev. Psychol., 69, 251). The current study examined whether 4- and 5-year-olds also associate others' behaviour with how they appear on the surface. Specifically, we asked whether children's sensitivity to different face-traits (e.g., Cogsdill et al., 2014, Psychol. Sci., 25, 1132) would bias them to associate knowledgeable behaviours with faces that adults rate as highly competent- or trustworthy-looking. We find that preschoolers expect puppets with trustworthy-looking faces to be knowledgeable about the functions of familiar objects. In contrast, children did not match a puppet's knowledge to facial features that adults rate as varying in competence. These data suggest that children, like adults, are biased to associate facial appearance and behaviour. Furthermore, this bias appears to be rooted in a response to the same facial features that have been found to govern judgements of trustworthiness across development (e.g., Jessen & Grossmann, 2016, J. Cogn. Neurosci., 28, 1728). Statement of contribution What is already known on this subject? Preschoolers selectively trust others using epistemic and non-epistemic cues (Harris et al., 2018). Preschoolers associate specific faces with trustworthiness and competence (Cogsdill et al., 2014). What the present study adds? Preschoolers infer that trustworthy-looking characters will behave knowledgeably. Preschoolers do not infer that competent-looking characters will behave knowledgeably. Children's reliability judgements are influenced by others' appearance.