You Have a Doppelganger and They Probably Share DNA, New Study Says

(CNN) — Sometimes when Charlie Chasen or Michael Malone are out alone in Atlanta, people mistake them for each other.

The lifelong friends who live in Atlanta are not related. Your ancestors don’t even come from the same part of the world. Malone’s family hails from the Bahamas and the Dominican Republic. Chasen’s family came from Scotland and Lithuania. Nor are they the result of a dark family secret. However, they look very similar.

It’s not just about their brown hair, beards, and glasses. They are also the structure of your nose, your cheekbones, and the shape of your lips.

“Michael and I have known each other for a long time and it’s been a source of a lot of fun for us because over the years we’ve been mistaken for each other everywhere in Atlanta,” Chasen told CNN’s Don Lemon. . “There have been some really interesting situations that have come up just because people thought we were the other person.”

The two look so much alike that even facial recognition software had a hard time telling them apart from identical twins. But now scientists think they can explain what makes them look so much alike, and could explain why each of us can have a doppelganger.

According to a new study, people who look alike but are not directly related appear to have genetic similarities.

Among those with these genetic similarities, many also had similar weights, similar lifestyle factors, and similar behavioral traits, such as tobacco use and education levels. This could mean that genetic variation is related to physical appearance and can also potentially influence some habits and behaviors.

Scientists have long wondered what creates a person’s doppelgänger. Is it nature or nurture? A team of Spanish researchers has tried to find out. Their results were published Tuesday in the academic journal Cell reports.

Dr. Manel Esteller, a researcher at the Josep Carreras Leukemia Research Institute in Barcelona, ​​Spain, said that in the past he had worked on research on twins, but for this project he was interested in people who look alike but don’t have a twin. real family connection going back nearly 100 years.

art leads to science

Esteller turned to art to answer a question about science. He and his co-authors recruited 32 people with similarities that were part of the photographic project “I’m not a double!”made by a Canadian artist, Francois Brunelle.

The researchers asked the couples to take a DNA test. The couples filled out questionnaires about their lives. The scientists also subjected their images to three different facial recognition programs. Of the people they recruited, 16 pairs had similar scores to identical twins identified with the same software. The other 16 pairs could look the same to the human eye, but the algorithm did not consider it that way in one of the facial recognition programs.

The researchers then examined the participants’ DNA. The pairs that the facial recognition software said were similar had many more genes in common than the other 16 pairs.

“We were able to see that these look-alike humans do, in fact, share several genetic variants. And these are very common among them,” Esteller said. “So they share these genetic variants that are related to the way they are shaped like their nose, eye, mouth, lips, and even bone structure. And this was the main conclusion that genetics brings them together.” .

It’s about similar codes, he said, but it’s just by chance.

“In today’s world, there are so many people that the system is ultimately producing humans with similar DNA sequences,” Esteller said. This has probably always been the case, but now with the internet it’s much easier to find them.”

Other factors at play

When they took a closer look at the couples, they determined there were other factors that set them apart, he said.

“That’s why they’re not completely identical,” Esteller said.

When scientists looked more closely at what they call the epigenomes of the doppelgängers that most closely resembled each other, there were greater differences. Epigenetics is the study of how environment and behavior can cause changes in how a person’s genes work. When scientists looked at the microbiome of couples who were most alike, they were also different. The microbiome is the microorganisms, viruses, bacteria and fungi too small to be seen by the human eye, that live in the human body.

“These results not only provide information about the genetics that determine our face, but could also have implications for the establishment of other human anthropometric properties and even personality characteristics,” says the study.

The study has its limitations. The sample size was small, so it is difficult to say that these results hold for a larger group of peers. Although the researchers believe that their conclusions would change in a larger group. The study also focused on couples who were mostly of European origin, so it’s not clear if the results would be the same for people who come from other parts of the world.

The Dr. Karen Gripp, pediatrician and geneticist at Nemours Children’s Health, whose investigation mentioned in this paper, said the study is really interesting and validates a lot of previous research.

Application of science in the real world

Gripp uses facial analysis software in his work with patients who may have genetic conditions to assess his patients’ facial features that might suggest certain genetic conditions.

“It’s a little bit different from the study, but it really points in the same direction that changes in a person’s genetic material affect facial structures, and that’s really the same underlying assumption that was used in this study as indeed confirmed.” , in contrast to some other things like the microbiome didn’t seem to be as relevant,” Gripp said.

As for the nature versus nurture question raised by the study, Gripp thinks both are important.

“As a geneticist, I firmly believe that nature and genetic material are very important to almost everything, but that doesn’t mean that education is just as important,” Gripp said. “For every person to be successful in the world there are so many contributing factors and the environment is so important that I don’t think it’s one or the other.”

a potential problem

The study also notes that the accuracy of facial recognition software still has limits. While several cities concerned about privacy issues and misidentification issues have enacted regulations banning or restricting local police from using facial recognition software, the federal government and some local law enforcement have been using it more frequently.

A 2021 federal investigation found that at least 16 federal agencies use it for digital access or cybersecurity, 6 use it to generate leads in criminal investigations, and 10 more said they planned to expand its use.

It is also used more frequently at airports. Some companies use it to help make hiring decisions. Some landlords have installed it so tenants can enter buildings. Some schools use it to take attendance and control movements in public spaces on university campuses.

“If you take this study out into the real world, you see that digital facial analysis tools could misidentify someone,” says Gripp.

Although the technology has been improvingprevious studies have already shown that it is much less accurate when it comes to identifying people of color, and several black men have been wrongfully detained because of facial recognition.

“If you think about facial recognition software that often unlocks computer screens and things like that, misidentification is possible. So I think this has taught us something very important about facial analysis tools as well,” Gripp said. .

But the study seems to suggest a conclusion. At least physically, we may not be so unique.

“I think all of us have someone who looks like us right now, a stunt double,” Esteller said.

While some would prefer to be unique in their looks, Malone, who happens to be friends with his stunt double, is encouraged by the fact that he’s not alone. His similarity to his friend has made them closer, and he thinks that if more people knew how similar they are to each other, maybe they too could find common ground, especially in this polarized world.

“It’s made me think that we’re all connected,” Malone said. “We’re all connected, because humanity probably started with one little thing.”