Not being able to tell the difference between people of another race has typically been seen as a sign of racism.
But the idea that “they all look alike” is actually something researchers have studied for decades. And social scientists say it may have more to do with the wiring in our brains than any deep-seated racist tendencies.
Researchers call it the “other race effect.”
“The other race effect is an effect that was found between the mid-1950s and 60s,” explains Assistant Professor Joan Chiao. “What a number of behavioral researchers and also legal experts have noticed is that there tends to be this phenomenon, whereby people seem to remember faces of their own races better than faces of other races.”
Chiao, who works in the Department of Psychology at Northwestern University, says that while there have been a number of behavioral and neuroscience studies of the other race effect, nobody has ever measured what exactly happens in the brain.
But a recent study at Northwestern set out to do just that. Professor Chiao and doctoral student Heather Lucas co-authored the study.
Lucas performed tests on subjects who were fitted with caps used to measure changes in voltage on the scalp.
The subjects were placed in a chamber where they were shown, in rapid succession, the faces of individuals of a particular race.
In some cases, they viewed faces of their own race. And in others, they viewed images of faces of another race.
“We recorded from electrode sites from sensors all over the head,” said Lucas.
“And this shows the pattern of activity across the whole scalp,” she explains, pointing to computer-generated images of scalps. “And these are averaged over time in milliseconds. So, zero millisecond[s] is right when the face first appears.”
The tests indicate distinct differences in scalp activity with regard to whether a face is remembered or forgotten. Those changes are distinctly different when the subject sees faces of their own race as opposed to faces of another race.
“What’s striking is for the other race faces, you see this kind of opposite pattern,” said Lucas. “You see a greater negative polarity for other race faces that were remembered relative to other race faces that were forgotten.”
What’s different about this study is that the brain activity can actually predict later memory, or how likely someone is to remember a person’s face; whether that’s someone of the same race or someone of another race.
“We found qualitatively different patterns of brain activity predicted whether the face was going to be remembered or not,” Lucas said. “So, you can imagine sometimes we remember faces and sometimes we don’t. But we found something qualitatively different was going wrong, something extra is going wrong or is kind of insufficient when trying to remember an ‘other race’ face, kind of beyond the factors that affect recognition for same race faces.”
The research is important obviously, in understanding how we recognize faces and people in social interactions. But it also has far-reaching implications in the realm of law enforcement as well. For example, in particular, with regards to the reliability of eyewitness testimony.
“Eyewitness identification testimony is so unreliable that, in my view, no conviction should ever rest solely on a stranger identification,” said Rob Warden, Director of the Center for Wrongful Convictions at Northwestern University’s School of Law.
Warden says the research is even more important when taking into consideration the number of convictions that rest on single or even multiple eyewitnesses. Add to that the other race effect, he says, proves further that the human mind does not work like a video camera.
“We know that cross-racial or cross-ethnic identifications are far more unreliable than identifications of the same race,” he said. “This research tends to shed light on that, which I don’t think that we ever understood before precisely. Not the way this research explains it.”
According to the Innocence Project, eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75 percent of convictions overturned through DNA testing.
At least 40 percent of these eyewitness identifications involved a cross-racial identification.
“There is virtually no defense against eyewitness testimony, unless of course you can impeach the credibility of the witness,” said Warden. “If you can prove that the witness could not possibly have seen what the witness testified to.”
And with the research that Lucas and Chiao have done, theoretically it could soon be possible to evaluate the reliability of an eyewitness.
“Prior to this investigation, we weren’t able to say exactly that we would necessarily be able to predict whether a face would be able to be well-remembered or not,” said Chiao. “We knew the regions that were associated, but not really exactly a neural signature. What we were able to successfully identify is a neural signature that can predict encoding success.”
But Jon Loevy, a civil rights attorney who works with the Exoneration Project at the University of Chicago, says the courts have traditionally been resistant to allowing expert testimony to question the fallibility of eyewitness accounts. That would make the introduction of scientific tests to evaluate eyewitness abilities highly unlikely.
“Well, hopefully it’s the beginning of an education process that will enable an evolution in the courts where people who have been there a long time will start to see this as a legitimate line of inquiry, a legitimate line of cross-examination,” said Loevy. “Until now, a lot of the judges, maybe some of the older judges, say there’s no place for it, we don’t need to hear some expert tell us eyewitnesses aren’t good or are good.”
Lucas says science could hold the key to unlocking just what makes the mind better or worse at recognizing faces of individuals of another race. So, the question that obviously arises is whether or not the mind can be trained to do a better job at it.
“It does seem like when you have more extensive experience and not just passing experience, but real meaningful interactions with other race individuals on a regular basis, it does lead to improved memory for faces of those races,” said Lucas.
Some legal experts say social science and research like this can play an important role in shaping how the courts deal with eyewitness testimony.
But they say, until conventional wisdom is set aside and science is used as a tool, wrongful convictions may continue to be an unjust consequence.
For more on the study, visit the links below.