"They all look the same" is a common expression regarding people of other races.
The “cross-race effect” is one of the most well replicated findings in psychological research and is one reason for the disturbingly common occurrence of eye-witness misidentifications.
The causes of the cross-race effect are unclear. Some psychologists argue that inherent segregation means some people don’t have much practice with individuals of other racial groups and are thus less capable of recognizing distinguishing features. Researchers from Miami University have a different idea. They argue this effect arises from our tendency to categorize people into in-groups and out-groups based on social categories like social class, hobbies, and of course, race.
In a series of experiments, Miami University undergraduates were led to believe that they would view the faces of fellow Miami students (the in-group) and students from Marshall University (a perennial football rival, making them the ultimate out-group) on a computer screen.
In reality, none of the faces, all of whom were white, were students at either university. By merely labeling them, however, the participants better recognized faces that they believed were fellow Miami students.
The study, conducted by psychologist Kurt Hugenberg and graduate students Michael Bernstein and Steven Young, will be published in the August issue of Psychological Science, a journal of the Association for Psychological Science.
Hugenberg and his colleagues believe the study suggests that recognition deficits can occur without the need for race or different physical characteristics, arguing instead that there is more than just unfamiliarity with other races at play in the cross-race effect.
According to the researchers, “people frequently split the world up into us and them, in other words into social groups, be they racial, national, occupational, or even along the lines of university affiliation. Our work suggests that the cross-race effect is due, at least in part, to this ubiquitous tendency to see the world in terms of these in-groups and out-groups.”