Two pictures of the same face can look very different, which is why many of us don’t like our passport photo. Trying to recognize faces when appearance varies is especially challenging when viewing faces of a different race, new Brock University research has shown.

In what is a twist to the common expression, “they all look the same to me,” a research team led by psychologist Catherine Mondloch found that people were twice as likely to believe that two pictures of the same person belonged to different people when sorting other-race photos compared to own-race faces.

“We’ve known for a long time that it is reasonably easy to recognize faces from our own age and ethnic group,” says Mondloch. “Yet, when we encounter people from a category with which we are less familiar – infant faces, other-races faces, older faces – we are less accurate.

“The research field has focused on the fact that we have a hard time telling some faces apart,” says Mondloch. “Now we know that telling faces apart is only part of the story. Our finding turns the field upside down a little bit; this is the flip side of the problem.”

Mondloch and her team, Xiaomei Zhou and Sarah Laurence, presented East Asian and Caucasian research participants with a pile of 40 photographs of either own or other-race faces.

The researchers asked participants to select photographs of the same person and put them into separate piles, so that each pile would contain all of the images of one person.

“What we didn’t tell them is the pile included 20 pictures of two people, so the correct solution was two piles each containing 20 pictures.” explains Mondloch.

“They didn’t know that. The number of piles each person made told us how many different identities they perceived.”

If the common perception that other-race faces look “the same” to someone of a different race, then, “people should make fewer piles when sorting other-race faces,” says Mondloch.

In previous research, when a British research team administered a similar test to participants to distinguish same-race images, participants made an average of six piles.

But in this latest research on other-race faces, “people made twice as many piles for other-race faces; they were making 11 or 13 piles. Rather than thinking there were six different people, participants perceived 13 different people when there were only two,” says Mondloch.

The results were the same with the East Asian and Caucasian participants.

All photographs were of the same two people, but with differences in lighting, facial expression, hairstyles, makeup and other small changes in appearance.

Mondloch says the research has important implications for passport officers and other professionals tasked with identifying individuals.

“It’s hard enough to match a person to their photo or to see that this driver’s license and this passport really belong to the same person because appearance varies from day to day,” she says.

“If these are pictures of somebody from categories that are not very familiar, like other-race faces, that’s going to be even harder, because that small change in appearance is going to lead you to think it’s a different person.”

The research findings also apply to everyday social situations, says Mondloch.

“There’s the awkwardness of failing to say hello to somebody you should recognize. This study suggests that’s going to be much more likely when it’s somebody from a different ethnic background,” says Mondloch.

“So now the question is, can we change that?”

Mondloch’s research – “The flip side of the other-race coin: They all look different to me” – was published September 14 in the British Journal of Psychology, http://onlinelibrary.wiley.com/doi/10.1111/bjop.12147/abstract