Children's judgements of facial hair are influenced by biological development and experience

Adults use features such as facial hair to judge others' social dominance and mate value, but the origin of these judgments is unknown. We sought to determine when these associations develop, which associations develop first, and whether they are associated with early exposure to bearded faces. We presented pairs of bearded and clean-shaven faces to children (2–17 years old; N = 470) and adults (18–22 years; N = 164) and asked them to judge dominance traits (strength, age, masculinity) and mate choice traits (attractiveness, parenting quality). Young children associated beardedness with dominance traits but not mate choice traits. This pattern became more extreme during late childhood and gradually shifted toward adult-like responses during early adolescence. Responses for all traits were adult-like in late adolescence. Finally, having a bearded father was associated with positive judgments of bearded faces for mate choice traits in childhood and both mate choice and dominance traits in adolescence