Identical from the face: in search of a double

Different nations equally share the belief that every person must have a double somewhere, his exact copy. But is there any truth in these superstitions? More than 7,4 billion people live on our planet. So there must be some possibility that many of them (other than twins) are very similar to each other.

There are doubles among Hollywood celebrities: in Russian Podolsk, for example, lives the Russian “Leonardo DiCaprio” Roman Burtsev, who, similar to a star, brought contracts in the advertising business. And numerous doubles of the King of Pop Michael Jackson travel around the world with tours and earn good money.

Tegan Lucas, a graduate student at the University of Adelaide, however, was not at all worried about the twins of the stars, but the frightening possibility that an innocent person could be mistaken for a criminal because of their resemblance. However, in his study¹ she found that the probability of matching all eight objective physical parameters of the face, such as the distance between the eyes and ears, is small – one in 135.

On the other hand, there is a big difference between the similarities that objective measurements (including facial recognition programs) reveal and the human eye. The fact is that the human brain does not store in memory a photograph of a human face, but a certain sketch of it.

When we meet friends on the street, the brain immediately begins to recognize familiar features, such as skin tone or hairstyle. In the same way, we immediately recognize Italy by its outlines on the map. But what if a friend cut his hair? Or very burned out?

In order for traits to be recognized in any context, the brain uses the fusiform gyrus – it is it that connects different characteristics together, as if, when looking for a country, we checked whether it has a border with France and a coastline. However, some details are still overlooked: “Most people concentrate on superficial signs, such as the hairline, hairstyle, eyebrows,” says Nick Fieller, a project specialist in computer face recognition.

Photographer François Brunel, who photographed 200 pairs of doppelgangers for his I Am Not Like project, agrees with this view. “Individually, my characters look like clones of each other. But when you put them in the same frame, side by side, sometimes it becomes obvious that there is nothing in common between them, ”he adds.

The easiest way to find your doppelganger is for people with common physical characteristics – for example, men with brown eyes, dark short hair and no beard have a higher chance than blue-eyed, long-haired blonds with a beard. This is statistics.

And yet why are some people so interested in this topic? “When we meet people like us, we feel an instant connection. After all, we already have something in common,” Brunel explains. And psychologist Lisa DeBruin from Canada’s McMaster University found out²that we trust people who look like us more and find them more attractive. The roots of these emotions may go back to our distant past, when external similarity was an important indicator of kinship for survival.

But in today’s overpopulated world, this principle no longer works. According to University of Bristol geneticist Lavinia Paternoster, “It is quite possible that two people with similar facial features have just as different DNA as two people who are completely different from each other.”

¹ T. Lucas, M. Henneberg «Are human faces unique? A metric approach to finding single individuals without duplicates in large samples», Forensic science international, September 2015.

² L. DeBruine «Facial resemblance enhances trust», The Royal Society Publishing, July 7, 2002.