It appears in your passport. It is according to him that the criminal is determined at a confrontation. It is by him that even after many years old friends will recognize you on the street.
Your face is so closely tied to your personality that it may soon become the only thing that will be required to unlock your smartphone, access the office and buy real estate.
All this is possible thanks to your unique appearance. But one day all illusions are shattered.
“I got on the plane last, and someone was sitting in my seat, so I had to ask him to move. He turned around - and I saw my face in front of me, ” recalls Neil Douglas, who flew to Ireland that day for a wedding. - The whole plane looked at us and laughed. That's when I and
took this photo. "
The strange sequence of events continued when Douglas arrived at the hotel and saw the same double at the front desk.
Later, their paths crossed again at the bar, and they decided that the universe is getting them to have a drink together.
The next morning, hungover, Douglas was awakened by a call from the Argentine radio - a joint photo of them with a double caused a heated discussion on the Internet.
Popular wisdom says that everyone has a double; somewhere around the world your exact copy is wandering - with eyes like your mother's, nose like your father's and with this stupid mole, which you are all going to remove.
This idea has occupied the minds of people for more than one millennium - it formed the basis of one of the oldest literary works that have come down to our days, served as a source of inspiration for poets and scared several queens to death.
But is there even a grain of truth in this? The question seems to be stupid, but it is more difficult to answer than it might seem, and the consequences can be very serious. More than seven billion people live on our planet - surely at least one of them was born with exactly the same face as yours!
In fact, until recently, no one tried to find an answer to this question. But last year, Tegan Lucas decided to assess the risk of an innocent person being mistaken for a murderer.
Armed with a publicly available collection of photographs of the American military and with the help of colleagues at the University of Adelaide, she meticulously studied the faces of nearly 4, 000 people, measuring the distances between key features such as eyes and ears.
She then calculated the likelihood that the faces of two people would be the same.
The results of the study are likely to delight the criminal justice system and disappoint those who have long dreamed of meeting their counterpart: the probability of coincidence with someone in just eight dimensions is less than one trillion.
Even though there are 7.4 billion people on the planet, the chance of having at least one pair of twins in the world is only one in 135.
“Previously, you could always be asked in court:“ What if that person was just like him? ”But now we can say that this is extremely unlikely, ” says Tegan.
Such results can be explained by the well-known "Infinite Monkey Theorem": if you put a monkey in front of a typewriter and wait long enough, in the end, by random strokes on the keyboard, it will certainly print the complete works of Shakespeare.
From a mathematical point of view, this statement is correct, but if you look, it becomes clear how incredibly long it would take a monkey to sweat for this.
Grammar aside, the probability of typing the first letter of Shakespeare's tragedy Macbeth correctly in English is one in 26. Not too bad.
But by the second letter the probability decreases to one in 676 (26 x 26), and by the end of the fourth line (22 letters) it drops to one in 13 quintillion.
If you multiply all the probabilities, it turns out that the chances of reproducing all of Shakespeare in a monkey are extremely small.
Moreover, the wide variety of human faces does not, of course, boil down to eight features.
According to Tengan, not just everyone has a "twin" - most likely, no one has it at all.
However, the story doesn't end there. The study was based on accurate measurements: if your doppelgänger's ears are 59 millimeters, and you have 60, your similarity does not count, no matter how strong it may be.
Although you can hardly remember the last time you determined the similarity of people by the size of their ears.
Other options are also possible - it all depends on who is considered a double. "You can talk about similarity 'from a human perspective' or similarity for a computer program of pattern recognition, " says David Oldus, a statistician at the University of California at Berkeley (USA).
François Brunel, who has photographed more than 200 pairs of doubles as part of his project I am not a copy, agrees with this statement.
"For me, similarity is when you see a person and take him for another. This is a form of being, the sum of all parts."
"When you look at each one individually, they look like real clones of each other. When they meet and see them side by side, sometimes it seems that they are not alike at all."
If you ignore the small details, the likelihood of having twins suddenly rises sharply. Is it so?
In order to find out, we first need to understand what happens when we recognize a familiar face.
Take, for example, a joke photo of the main US presidential candidates Bill Clinton and Al Gore, which went around the entire Internet before the 1997 elections.
At first glance, the image is unremarkable: just two men nearby. However, upon closer inspection, it is revealed that the "inner" facial features (eyes, nose and mouth) in Gore are replaced by those of Clinton.
And even with "alien" eyes, nose and mouth, while maintaining the general structure of the face, Al Gore looks quite recognizable in this image.
This amazingly demonstrates how faces are stored in our memory - more like maps than images.
If you bump into a friend on the street, the brain immediately begins to work on recognizing her specific features, such as hair length or complexion, - much as if it recognizes Italy only by its shape.
But what if your friend just got her hair cut? Or did you make up?
To recognize a person under any circumstances, the brain uses a site called
"fusiform gyrus" for bringing all facial features together.
If we compare this process with the search for a state on a map, one can imagine that we are looking for a country that borders on France and has an outlet to the sea.
It is believed that such a holistic perception of the "sum of all parts" allows us to recognize our acquaintances much more accurately than if the brain perceived their features separately.
Significantly, it also diminishes the importance of some of the finer details.
"Most people concentrate on superficial characteristics like hair length, hairstyle, eyebrows, " says Nick Filler, a statistician involved with a computer-based facial recognition program.
In other studies, it has been found that a person looks first at the eyes, then at the mouth and nose.
Then it's just a matter of determining the likelihood that someone else will have similar traits.
"There are not so many genes responsible for the shape of the face, and there are millions of people, so this must inevitably happen, " says Winrich Freiwald, who studies facial perception in
"It is relatively easy for a person with an average face to find their own kind, " agrees Filler.
Imagine a man with short blond hair, brown eyes, a fleshy nose (like the British Prince Philip, Duke of Edinburgh), a round face, and a thick beard.
There is almost no data on the prevalence of such facial features, but this gentleman has a very good chance of finding a double: 55% of the world's population has brown eyes.
At the same time, according to a study sponsored by one of the cosmetics manufacturers, round faces are more common than in every tenth case.
Next is the nose. A study of photographs taken in Europe and Israel shows that a fleshy nose is the most common option (24.2%) - and in the author's opinion, the least attractive.
Finally, the hairline remains. If you think this subject is trivial for serious research, then you are wrong: of the 24, 300 people who took part in the study at an amusement park in the US state of Florida, 82% of men had hair shorter than shoulder length.
However, only 2% of natural blondes were found. In addition, in Great Britain, which is jokingly called "the land of the bearded, " most men have facial hair, and almost one in six has a thick beard.
A simple calculation (multiplying the proportions of men, brown-eyed, blond, chubby, owners of a fleshy nose, short-haired and bearded) shows that the probability of meeting a person with all these characteristics is slightly more than one in 100 thousand (0.00001020%).
This means that on a planetary scale, our imaginary man may have as many as 74 thousand potential doubles.
Of course, many of the values that indicate the prevalence of a particular trait are not applicable to the whole world, so our calculations are very rough.
However, judging by the number of "doubles" of various celebrities, we are not so far from the truth.
“After our joint photo spread all over the Internet, at some point it seemed to me that I had a whole army of twins, ” says Douglas.
So what is the likelihood that everyone in this world has a double?
The easiest way to find out is to estimate the number of face variants and compare it with the number of people living today.
One would expect that even if there are 7.4 billion different variants of faces in the world, then with a population of 7.4 billion, each of them occurs once.
However, not all so simple. In order for this to be statistically probable, in fact, the Earth would have to be home to about 150 billion people.
This discrepancy is due to a statistical quirk, which is well illustrated by the problem of choosing coupons.
Let's imagine that there are 50 coupons in the container and every time one of the coupons is taken out, it is immediately put back.
How many times will you have to pull out coupons to get each of them at least once?
It doesn't take long to get the first few coupons. It is much more difficult to get the last ones: on average, even to get only the last one, it takes about 50 attempts, so all 50 coupons will take about 225 attempts.
Therefore, perhaps most people have doubles. But for everyone? "There is a big difference between occasional and constant luck, " notes Oldus.
Nobody knows exactly how many face options there are. And, perhaps, we will never get an unambiguous answer to this question, since the perception of similarity is subjective.
Some people hardly recognize themselves in photographs, and some rarely forget other people's faces.
Our perception of similarity is highly dependent on the degree of closeness of our acquaintance.
"Some doubles, meeting, say: no, I do not see the similarity. True, I do not. And to everyone else it is so obvious that such a statement seems stupid, " Brunel notes.
Even so, Filler says the likelihood of having a twin is pretty high.
“It seems to me that most people have someone outwardly similar, unless they have some very unusual and outstanding face, ” he says.
Frevald agrees with him. “I think that in the digital era that we are now entering, there will come a time when we will know for sure, since photographs of almost all people will be posted on the Internet, ” the scientist is convinced.
Why are we interested in this topic at all? "When similar people meet each other, a connection immediately arises between them, because they have something in common."
Brunel received responses from thousands of people who were looking for their counterparts, especially from China (this feature he considers a consequence of the policy of containing the birth rate to one child per family).
Studies have shown that we consider people like us more attractive and trustworthy - it is believed that this factor plays a role in the choice of the candidate for whom we will vote in the elections.
Perhaps this phenomenon is rooted in our deep past, when external similarity served as a sign of kinship.
In today's globalized world, this relationship has long been lost. "It is possible that outwardly similar people will have as different DNA samples as two bystanders, " said Lavinia Paternoster, a geneticist at the University of Bristol (UK).
And before dreaming about how you and your "twin" will sometimes change places in different situations, keep in mind: there is no guarantee that you will be alike in everything.
“I’m one meter seventy and he’s one meter ninety ... So we are only similar in face, ” says Douglas.