Inequality between biases in face memory: Event-related potentials reveal dissociable neural correlates of own-race and own-gender biases.

Humans are more accurate at remembering faces from their own relative to a different ethnic group (own-race bias). Moreover, better memory for faces from an observer's own relative to the other-gender (own-gender bias) has also been reported, particularly for female participants. Theoretical explanations for these effects either emphasize differential perceptual expertise or socio-cognitive factors. Importantly, both types of explanations typically assume a single common mechanism for the various biases. The present study examined event-related potentials (ERP) in a combined own-race/own-gender bias experiment. Whereas both male and female participants demonstrated clear own-race biases in memory performance, enhanced memory for own-gender faces was only observed in female participants. Moreover, the own-race bias was accompanied by larger N170 responses for other-race faces, presumably reflecting more effortful perceptual processing of this face category. Neural correlates of the own-gender bias manifested at later processing stages, reflecting the processing of individual faces (N250) and recollection-based memory retrieval (late ERP old/new effect). We conclude that different face memory biases occur at temporally distinct stages of face processing and are therefore based on different mechanisms. This suggestion is at variance with the assumption of a single common mechanism to underlie the various biases in face memory.