How often have you heard, “Oh, you look like that actress,” and thought, “That’s not like me?” Wouldn’t it be cool to think that one of the world’s most attractive people was your twin?

What happens in the Brain?

Here is what your brain does when it recognizes someone: 

• It transforms into a small, squishy computer programmer, with each aspect of a person’s face representing a code. 
• Except for one flaw, this face recognition system would be an effective way of distinguishing one human from another. 
• You could read someone’s face in the following order: eyes, mouth, nose. The size and placement of her eyes influence how you perceive the rest of her face. 
• Someone else might interpret these features in the following order: nose, mouth, and eyes.
• The same signals reach the brain, but their jumbled order shifts their emphasis to the nose and modifies how the rest of the face is perceived. 
• We all perceive each other differently in this way, which calls into question the veracity of doppelgängers.

The picture painted by studies of unrelated look-alikes is murky, but scientists are aware that genes are the most significant factor because identical twins resemble one another more than fraternal twins, and siblings frequently resemble one another more than strangers do. This indicates that genes control the processes that shape our faces.

As per the Research

An international team of researchers looked at more than 15,000 faces, all of European ancestries, in search of patterns that might provide evidence. Measurements like eye width and distance from the nose and mouth allowed them to categorise the participants who shared a similar appearance objectively. The genes in the two groups were then compared. The team found five unique genes that shape the face and published their findings in Plos Genetics. The researchers were less interested in proving the existence of doppelgängers than they were in laying the foundation for an exact and reliable method to identify a face’s appearance. In the future, researchers may create a tool to aid forensic scientists like Daniele Podini in reconstructing a face from a single piece of DNA by learning more about these genes.

Although almost science fiction, Podini maintains that it is conceivable in theory. Although this kind of technology would be ideal, he claims that there are other factors to take into account. “I saw a picture of identical twins; one was a smoker; they looked different.” Podini believes that understanding our genes alone is insufficient because our behaviour and way of life also affect how we look. This means that a technology that uses DNA to create a matching face would need a significant amount of genetic material, enough to allow the scientist to include behavioural data, which is frequently not left at a crime scene.

Axel Visel, a geneticist at Berkeley National Lab, has gene enhancers to add to the do doppelgängers roam the earth debate. These DNA sequences function as switches in our bodies, turning certain genes on and off. Individual variations in the “exact sequence” of these enhancers can alter how they function.

Visel acknowledges that it is “tempting” to conclude that these enhancers, when expressed in specific combinations, are the cause of why even unrelated people can occasionally look alike. He expresses concern that there is currently no evidence to support this claim. However, he is working on it with his team.

It might even be as easy as visiting a salon or barbershop one day and leaving with a new haircut to be mistaken for someone’s twin. Marlene Behrman, a neuroscientist at Carnegie Mellon who studies prosopagnosia, says that updating our facial recognition system to account for variations caused by a different hair colour or even just a haircut can be difficult.

Prosopagnosia, also known as face blindness, makes it difficult for some people to distinguish between different faces. It has been linked to damage in the fusiform gyrus, a part of the brain that aids in facial recognition. She continues, “It’s like having dyslexia, but for faces.” The disorder can manifest itself without any brain injuries, but it also affects people whose brains have been damaged.

Finding someone who looks exactly like your childhood best friend might be exciting, but the ability to recognize faces is a survival tool designed to keep us safe. According to Behrmann, “you would think that recognizing faces, something so crucial to differentiating friend from foe, would be very fine-tuned but it’s very hard for us.” According to Behrmann, there is a strong case against the existence of doppelgängers being a myth because of our difficulty in pinning down a face.

Also published on Medium.