"We were able to pinpoint where and when race matters at a neural level," says Jennifer Eberhardt of Stanford University, California. She and her colleagues recorded activity in the fusiform face area (FFA) of the brain as African- or European-Americans studied pictures of faces from different races. The FFA was more active when either group was learning and recognizing faces of the same race, they found
People with damage to the FFA lose their knack with faces. Such a man, suffering from prosopagnosia, featured in Oliver Sacks' story 'The man who mistook his wife for a hat'. But whether face recognition is innate or learned is still a hot debate.
"[The FFA] responds more to faces than objects," says Isabel Gauthier of Vanderbilt University in Nashville, Tennessee, "we all agree on that." But car buffs and bird spotters use the same brain region when distinguishing cars or birds, Gauthier and her colleagues showed last year
The brain's processing switches as we acquire expertise, thinks Gauthier. Move the eyes in a face and it becomes difficult to recognize; similarly, car experts find it hard to tell a motor's make when the positions of the parts are moved. Experts look at the whole thing, thinks Gauthier; novices look at the pieces.
Same-race recognition is consistent with the expertise idea; most people have greater contact and experience with faces of their own race. Studies of children to determine when the preference emerges may help to tackle this question.
Although the cause of the race bias has yet to be determined, the study is fascinating, says Elizabeth Phelps, a social psychologist at New York University. Not only are faces clearly special, "it's a cultural phenomenon," she says.
Looking at the brain activity underlying social interactions holds incredible interest, says Phelps. This study is one of the first to look at the how membership of social groupings such as gender, sex and race influence behaviour. "It's exploding right now," she says.