You have a ‘double’ in the world and likely with shared DNA, study says

Sometimes when Charlie Chasen or Michael Malone are alone in Atlanta, people confuse them.

Longtime 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 a lot alike.

It’s not just about his brown hair, beard and glasses. They are also the structure of the nose, the cheekbones and the shape of the 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 confused for each other everywhere in Atlanta,” Chasen told Don Lemon of CNN . “There were some really interesting situations that came up just because people thought we were the other person.”

The two are so similar that even facial recognition software has had a hard time telling them apart from identical twins. But now scientists think they can explain what makes them so alike, and they can explain why each of us might have a double, or “duplicate.”

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 influence some habits and behaviors.

Scientists have long wondered what creates a person’s duplicate. Is it nature or nurture? A team of Spanish researchers tried to find out. Their results were published Tuesday (23) in the academic journal Cell Reports.

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

Art leads to science

Esteller turned to art to answer a question about science. He and his co-authors recruited 32 look-alikes who were part of the photo project “I’m not a stuntman!” , made by a Canadian artist, François Brunelle.

The researchers asked couples to take a DNA test. The couples filled out questionnaires about their lives. The scientists also ran their images into three different facial recognition programs.

Of the people they recruited, 16 couples had scores similar to identical twins identified with the same software. The other 16 pairs might look the same to the human eye, but the algorithm didn’t count it that way in one of the facial recognition programs.

The researchers then examined the participants’ DNA. The pairs that 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 how they have the shape of their nose, eyes, mouth, lips and even bone structure. And that was the main conclusion that genetics bring 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 producing humans with similar DNA sequences,” Esteller said. It’s probably always been that way, but now with the internet it’s a lot easier to find them.”

Other factors at play

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

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

When the scientists took a closer look at what they call the epigenomes of the most similar duplicates, there were bigger 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 that are too small to be seen by the human eye and 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 traits,” the study says.

The study has its limitations. The sample size was small, so it is difficult to say that these results are valid for a larger group of peers. Although the researchers believe their conclusions would change in a larger group. The study also focused on couples who were mostly of European origin, so it’s unclear whether the results would be the same for people who hail from other parts of the world.

Karen Gripp, a pediatrician and geneticist at Nemours Children’s Health whose research is referenced in this article, 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 may suggest certain genetic conditions.

“It’s a little 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.” for some other things like the microbiome don’t seem to be that relevant,” Gripp said.

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

“As a geneticist, I strongly believe that nature and genetic material are very important to almost everything, but that doesn’t mean that education is as important as that,” 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 that prohibit or restrict local police from using facial recognition software, the federal government and some local authorities use 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 plan to expand its use.

It is also used more often in airports. Some companies use it to help make hiring decisions. Some homeowners have installed it so that tenants can enter the buildings. Some schools use it to provide care and control movements in public spaces on university campuses.

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

While the technology has improved, previous studies have shown it to be far less accurate at identifying people of color, and several black men have been unfairly detained due to facial recognition.

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

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

“I think we all have someone who looks like us now, a doppelganger,” Esteller said.

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

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