An infamous concept in psychology is the 'Other Race Effect.' People are able to differentiate between faces of their own race better than between the faces of other races. A new study probes the mechanics of the phenomenon.

The Other Race Effect, and its equally unpleasant sounding attendant, the 'all look alike' phenomenon have been well known for most of a century. People of a certain race easily recognize individual faces of members of their own race, but are much less able to distinguish between the faces of members of other races. This leads to lack of recognition of supposedly familiar faces as well as misidentification - when people 'recognize' someone who they've never seen.

A new study, conducted by researchers at the University of Glasgow and the University of Fribourg, uses an electroencephalogram to measure the brain's response to different faces. In particular, it takes a look at repetition suppression. Repetition suppression is a brain's response to repeated images. When the brain sees an object for the first time, it kicks into gear, picking up all the subtle differences between that object and every other one. This response is especially large for human faces. If the same object is shown several times, repetition suppression occurs. The brain takes in just enough information to realize that it's seeing the same object - 'coding' the object - and loses interest.


During the study, Western Caucasion and East Asian people looked at pictures in sets of two. Each set of pictures was of members of the same race. In some sets, the second picture was of the same person. In others, it was of a different person. Each picture had a different expression, to make sure that the observers were memorizing facial features, not static pictures.

The study showed that repetition suppression set in fastest, and most efficiently, for members of the observer's own race. After being shown the same person twice, the brain recognized that it had seen them before. It 'coded' the person's features and moved on after correctly identifying them.


When subjects observed pictures of a members of a different race, the brain did a similar thing. It coded the information about the person, dampening the initial search process. The difference was, it did it even if the second picture was of a different person. Although the actual features were new, the brain had decided it had already seen them and repetition suppression kicked in.

The study says nothing about the social component or cause of the Other Race Effect. The paper itself says that more study is necessary to even fully understand its mechanics.

All these ERP studies relied exclusively on data from the [Western Caucasion] population, which is a methodological problem, because any effect could be confounded by physical differences in the face stimuli, preventing any firm conclusion on the ORE [Other Race Effect]. A full crossover interaction between races of observers and the race of faces is necessary to assess genuine behavioral and neurophysiological ORE. To the best of our knowledge, only one electrophysiological study used two groups of observers and reported sensitivity to race for inverted faces in two groups of observers.

It does, however, show that its effects can be immediate. Under the right circumstances, we can forget we saw a particular individual's face almost as soon as we've seen it.

Via the Proceedings of the National Academy of Science.