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Your lookalike is out there, and you may have more in common with them than just a face!8 min read

September 2, 2022 6 min read


Your lookalike is out there, and you may have more in common with them than just a face!8 min read

Reading Time: 6 minutes
Four pairs of “human doubles” included in the study. Photo: François Brunelle

What do you think about these 4 pairs of people? They definitely look related, right? Siblings perhaps? Or even cousins!

Now, what if I was to tell you that they absolutely are not! In fact, they are what we called doppelgängers.

Wait, doppel what?! Yes, this complicated word with the little dots on the ‘a’ is clearly not an English word. This word has its origins in German, and goes back to tales of lore.

Let’s understand what a doppelgängers is first:

A doppelgänger or doppelganger is a biologically unrelated look-alike, or a double, of a living person. In fiction and mythology, a doppelgänger is often portrayed as a ghostly or paranormal phenomenon and usually seen as a harbinger of bad luck. Other traditions and stories equate a doppelgänger with an evil twin.

In German folklore, a doppelgänger is a ghost-like figure or apparition of a living person. The concept of the existence of a spirit double, an exact but usually invisible replica of every man, bird, or beast, is an ancient and widespread belief.

Luckily, there are no ghosts or evil twins in this story. So, now that we have got that out of the way, let’s move on.

Somewhere out there, in another corner of the world, there’s probably a person who has your face. And this unrelated look-alike may have more in common with you than just appearances, a new study suggests. 

The surprising and interesting research, based on 32 pairs of unrelated doppelgängers from around the world, shows that two people who have a strong facial similarity to each other, are also likelier to share significantly more of their genes and be more likely to share similar behaviours. However, the genes that get switched on or off, and the microbial ecosystems in the two people’s bodies, still differ. 

What this means is that the microbiomes, or communities of helpful and harmful microbes that live on and in the human body, and different epigenomes, or variations in expressed traits influenced by the experiences of past generations, are still different.

Wow! That was a complicated sentence. Luckily for you, there is a glossary of important words below that can help you make sense of the above mind-boggling statement!

Did you know?

Given that there’s about 8 billion people on the earth, that’s a roughly 0.11 percent chance of any given person having a ‘twin stranger’. Or, in other words, for any group of 10,000 people, about 11 of them should have a doppelgänger.

For the study, these ‘virtual twins’ had never met and were instead brought together thanks to the work of Canadian artist and photographer François Brunelle, who had been collecting pictures of lookalikes since 1999!

The researchers published their findings August 23 in the journal Cell Reports. The image below is an example of all those years of work.

A pair of lookalikes photographed by François Brunelle.
Photo: François Brunelle

Important words you should know!

GenesThe basic unit of heredity passed from parent to child. Genes are made up of sequences of DNA and are arranged, one after another, at specific locations on chromosomes in the nucleus of cells.

DNA – The molecule inside cells that contains the genetic information responsible for the development and function of an organism. 

ChromosomesA structure found inside the nucleus of a cell. A chromosome is made up of proteins and DNA organized into genes. Each cell normally contains 23 pairs of chromosomes.

Epigenome – Within the complete set of DNA in a cell (genome), all of the modifications that regulate the activity (expression) of the genes is known as the epigenome.

Genomics – The study of the complete set of DNA (including all of its genes) in a person or other organism. 

Genetic variation – Genetic variation is the presence of differences in sequences of genes between individual organisms of a speciesA person’s skin colour, hair colour, dimples, freckles, and blood type are all examples of genetic variations that can occur in a human population.

“Our study provides a rare insight into human likeness by showing that people with extreme lookalike faces share common genotypes, whereas they are discordant (different or disagreeing) at the epigenome (the genes which are switched on or off due to our environmental or lifestyle factors. ) and microbiome levels,” senior author Manel Esteller, the director of the Josep Carreras Leukaemia Research Institute in Barcelona, Spain, said in a statement.

“Genomics clusters them together, and the rest sets them apart.”

The interesting study

For the study, the 32 look-alike pairs completed a lifestyle and biometric questionnaire in their native languages, and the researchers used three different facial recognition algorithms to score the pairs’ likenesses — of which half were considered doppelgängers by all three algorithms. 

Taking these 16 highly similar pairs, the researchers then investigated their genomic structure through a process called DNA analysis. The analysis revealed that nine of the 16 pairs were “ultra” lookalikes — they not only appeared closely related, they also shared 19,277 common genetic variations in 3,730 genes. However, these extreme lookalikes were no more likely to share similar epigenetics or microbiomes than pairs that did not look alike. This means that their environmental and lifestyle factors did make a difference in how similar they are! Even the microbes that sit in their bodies, are different.

Many of the lookalikes didn’t just share some of their genetics either, but also had similar habits, education levels and weights — a reminder that behaviour can be profoundly influenced by genes. 

“These findings do not only provide clues about the genetic setting associated with our facial aspect, and probably other traits of our body and personality, but also highlight how much of what we are, and what defines us, is really inherited or instead is acquired during our lifetime,” the authors wrote in the study.

Perhaps most fascinating of all is that these genetic similarities between unrelated doppelgängers occurred by random chance. This suggests that the combinations the human genome can take are far from infinite, especially on a planet that is fast approaching a population of 8 billion people.

“These results will have future implications in forensic medicine — reconstructing the criminal’s face from DNA —and in genetic diagnosis — the photo of the patient’s face will already give you clues as to which genome he or she has,” Esteller said. “Through collaborative efforts, the ultimate challenge would be to predict the human face structure based on genes and other factors.”

Does this study pose any problems?

In their paper, the researchers acknowledge that the study is limited by its small sample size, which is “due to the difficulty to obtain look-alike data and biomaterial”.

Another limitation is that the study participants were mostly European, although the few studied Hispanic and Asian pairs showed the same results as the European pairs.

Did you know?

Believe it or not, scientists say that statistically, every person has roughly SIX doppelgangers out there in the world. That means there are seven people with your face, including you, out there.

How is this study useful?

The findings of this study may open up new research avenues. The findings provide insights into the genetics of the human face and have potential future applications in various fields, such as biomedicine and forensics.

In the future, Dr Esteller hopes it may be possible to infer from facial features “the presence of genetic mutations associated with a high risk of developing a disease such as diabetes or Alzheimer’s”.

Another potential application of these findings is in the field of forensic medicine, where it may be possible to reconstruct a criminal’s face from DNA.

Can you think of any other cool ways this research can humankind?

Sources: New York Times, CNN, How Stuff Works, Medical News Today