The influence of positive and negative facial expressions on face familiarity.

Recent studies have shown that smiling faces are judged as more familiar than those showing a neutral expression (Baudouin, Gilibert, Sansone, & Tiberghien, 2000). Here we compare judged familiarity of unknown and famous faces when displaying a positive, neutral, or negative expression. Our results confirm a smiling familiarity bias, with positive-expression faces judged as being more familiar. Importantly, we also show significantly reduced familiarity for negative-expression faces, compared with neutral- or positive-expression faces. This difference in judged familiarity is not due to differences in expression intensity, but instead related to expression valence. Results are discussed with regard to the independence of facial identity and expression processing, and in terms of factors that influence face familiarity and memory.