The Marvel of Facial Recognition
WHAT IS A SUPER RECOGNIZER?
Are you a super recognizer?
There are people who never forget a face— and can recognize others better than any computer. Could you be one of them?
It’s the biggest manhunt to take place in London since the 7/ 7 bombings in 2005: When Alice Gross suddenly disappears on August 28, 2014, the Metropolitan Police send 600 officers to look for the 14-year- old. They search streets as canine squads probe parks and residential areas and police divers scour the beds of rivers and canals. But it’s all in vain—until a new police unit succeeds in cracking the case. In a very short amount of time, the 20 super-recognizing members of this special unit manage to do what their colleagues couldn’t: They lead investigators to the girl’s body and identify her murderer, Arnis Zalkalns, using only their eyes and minds, and without ever leaving their desks at New Scotland Yard…
HOW CAN 100,000 PHOTOS REVEAL A KILLER?
Super recognizers have a unique ability: They practically never forget a face—and can recognize it again and again regardless of whether it appears in a blurred photograph, an infrared image, or an image in which the face is partially obscured. It’s a precise determination process that works like clockwork. To find Alice, super recognizers evaluate images from the 300+ surveillance cameras positioned in a 2.3-square-mile area around Grand Union Canal, which is where the girl had last been spotted.
The team must identify suspects from among tens of thousands of mostly blurred or indistinct images. To most people, the images would just look like a collection of pixels— but not to a super recognizer. The reason? “Not everyone sees things in the same way,” explains Detective Chief Inspector Mick Neville, leader of the Central Forensic Image Team.
I hardly ever forget a face, and I’m able to recognize you immediately.”
The specialists retrace the route Alice took through London as well as that of the culprit seen in a photo, since he was also reported missing.
CAN YOU BOOST YOUR ABILITY TO RECOGNIZE FACES?
On average, people remember only one out of five faces. As for a super recognizer? “We can’t say for certain that these folks never forget a face, but they can remember people they had a mere fleeting encounter with 10 years ago,” says Josh P. Davis, a psychologist at the UK’S University of Greenwich. These individuals can even outperform a computer: Even the most advanced computer can’t match up a childhood photo with an image of the person as an adult—a task that is not easy even for super recognizers. Nevertheless, in a test conducted at Gettysburg College in Pennsylvania, super recognizers did manage to correctly match up about half of the 56 childhood photos of celebrities shown to them—10 times the average population’s top score. Meanwhile, recognition software can fail if the target person is grimacing. Detective Neville cites the example of the 2011 riots in Central London, when the software was used. “Our database had 4,000 images and the software identified one rioter. One,” admits Neville. “In the same case, a single super recognizer was able to identify 180 people.”
The investigation entailed making the best sequences from hundreds of thousands of hours of captured CCTV footage available to the super recognizers—as soon as possible. “Whenever a serious crime such as murder occurs or there is a threat to public safety, all members receive one or more images via smartphone. But they are not provided with any background information about the case so they can’t be unintentionally steered in a certain direction,” says Davis. But just because someone recognizes a face in a photo doesn’t necessarily mean this is enough for a suspect to be found guilty in court, just as a fingerprint at a crime scene
A super recognizer can identify 180 times more faces than a computer.”
doesn’t prove the guilt of its owner. “But an image is evidence, and as such, it’s just as effective as fingerprints and DNA,” explains Neville.
It is estimated that 1 to 2% of the population have this special ability, but most don’t realize they have it.
“I didn’t know how good I am until I took a test,” says super recognizer Gary Collins, who’s among the best in his field. There’s no trick to it, and it cannot be learned: “Something in my head just ‘rings’ whenever I see a familiar face,” Collins explains.
ARE FACES ENCRYPTED?
You’re either a super recognizer or you’re not. ( Take the test, at right.) To date, these people are a mystery for researchers. Just as mysterious: They’ll forget inanimate objects just as fast as an average person does in tests. Furthermore, some of them have trouble remembering names— they only recall where they saw the person and how he or she looked. “We still know very little about how these individuals are able to more
effectively utilize the brain centers responsible for recognition of faces. Nevertheless, we’ve found that their ability seems to be inherited,” says psychologist Josh Davis.
The basic features of a human face can be arranged in about 5 sextillion possible combinations, which means in theory there are 700 billion times more discernible faces than there are people on the Earth. This means that every face is like a unique code and super recognizers can decipher it better than the general population, although we all read faces the same way: “Brain scans have shown that the brain first perceives the basic shape of a face. Then it establishes the relative spacing between eyes, nose, etc. Only at the end does it ‘look’ at the face as a whole. Super recognizers are better at this,” says Davis. This ability is indispensable to London’s police, and conviction rates have risen. Above all, the specialists save investigators time—time to find criminals before they can strike again.
I didn’t know anything about it. Then a test showed: I’m a super recognizer.”
THE QUICKEST SENSE It only takes fractions of a second for the brain to recognize a face— even though there are an estimated 5 sextillion distinct combinations of possible facial features.