You’ve heard the racial epithet: All you people look the same. It’s detestable, but a new study shows that the racist observation happens to be true. To members of one race, members of another race are far more difficult to differentiate.
The study, written by a European team led by Luca Vizioli of the University of Glasgow and published in a recent issue of the Proceedings of the National Academy of Sciences, begins by noting that humans are remarkably skilled at facial recognition: we can differentiate family members and friends from strangers in far less than a second. (More on Time.com: The Authentic Self: How Do You Know If You’re ‘Really’ Racist or Sexist?)
And yet as long ago as 1914, an academic publication called the Journal of Criminal Law and Police Science published an article saying it takes us longer to tell apart members of races other than our own. “To the uninitiated American,” the authors wrote, “all Asiatics look alike, while to the Asiatics, all White men look alike.”
The authors of the new study set out to discover why this “perceptual illusion,” as they call it, has persisted.
To study how we see others’ faces, they looked at electrical signals coming from the heads of 12 people of East Asian descent and 12 people of Caucasian descent as they viewed photos of members of their own and the other race. Previous studies had looked at whites only.
The signals are measured with electroenchephalography, or EEG, and they offer a strong clue about how much neural activity is occurring when any particular picture is on the screen. (More on Time.com: I Don’t Actually Hate Myself: Why Harvard Is Wrong About Bias)
The study found that, as expected, both Asian and white observers revealed what is called the “other-race effect”: they took longer to recognize members of other races.
The authors controlled for differences in how the faces in the photos looked. It didn’t matter whether someone was pretty or ugly, whether they were making a nice face or a rude one: it still took longer to recognize them if they were a member of another race.
What do these results mean? The authors are careful on this point. The idea that racism is built into our DNA is both unsavory and disappointing. Also, the sample is small: just 24 people. But the results suggest that we are programmed to see members of other races as, literally, different beings. The “‘all-look-alike’ perceptual experience,” as the authors call it, is real. (More on Time.com: I Know the Truth, So Don’t Bother Me With Facts)
These impulses are almost certainly evolutionary: we react against a member of another tribe that may be trying to annihilate us. One silver lining: understanding these impulses may help us to overcome them.