by by Matt Surka

illustration by by Emily Martin

Throughout history, people have been fascinated by the idea of the Invisible Man. In movies, novels and comic books, invisibility has played roles ranging from Potter-friendly plot devices to H.G. Wells' killer-enabling curse. Psychology shows us, though, that the Invisible Man can be far more than just fiction.


A British tank grumbles down an empty stretch of desert road, its solitary purr pushing ripples through the still night air. Hearing the sound, an enemy scout perched on a nearby hill breaks out his infrared scope and points it directly at the tank, one finger rooted anxiously to the "call" button of a handheld short-range radio.
He sees a motorcycle. The alarm goes unsounded; the tank tiptoes on.
So goes the hypothetical scenario promised by Intermat, one of many international companies that specialize in developing state-of-the-art camouflage. Applied selectively, the heat-masking foam Intermat manufactures can trick an infrared-equipped sentry into mistaking a troop crawler full of soldiers for a harmless motorbike, according to Bill Filis, assistant director of the project who was recently interviewed by The Economist. High-tech innovation like this represents a new wave of development for an antique principle: scientific remodeling of the element of surprise.
While the technology may be on the cutting edge, the tactics aren't. The ancient Chinese military commander Chieh Hsüan said that a state can only be penetrated if "the state has worms," meaning that the success of espionage depends on the vulnerabilities of the target. To dupe someone, you must come armed with an intimate understanding of your target's weaknesses. Lucky for you, the human brain has several.
Hans von Hentig writes in his 1931 article "The Pickpocket: Psychology, Tactics and Technique" that clever escape s should be timed to occur "when the members of the crowd are at once tired, excited and diverted." Humans suffer from chronically selective attention; they have a very limited capacity for dividing their focus between multiple streams of information. Creeping by a clingy ex-boyfriend without being spotted or jumping the gate at a subway station call for neither extreme dexterity nor speed; to move about undetected requires only an understanding about how people see, hear and shift their attention. Stealth goes to the observant.
Selective attention is just one among many flaws in human cognition, and researchers at the US Army Research Laboratory have dedicated their careers to taking advantage of others. For decades, soldiers wore combat fatigues covered in 'tiger stripes' to help them hide. Experimentation in the infant field of 'clutter metrics,' where researchers use eye-tracking technology to figure out what humans have a hard time seeing, finally proved tiger stripes ineffective just a few years ago. In today's wars, Western armies wear uniforms covered in pixel patterns, arrays of tiny blocks that confuse and ward off the gaze of an enemy.
Soldiers may realize the value of camouflage, but sneaking around outside of a military context tends to be viewed as something slimy or childish, reserved for cat burglars and cowards. Adults aren't supposed to hide; they ought to deal with their problems honestly and head-on. Consider, though, whether frankness has much value when you suddenly spot last night's vodka-fueled encounter walking down the sidewalk in your direction, or when two lovebirds, unaware of your presence, half-fall into the room you are sitting in, intent on doing things you would rather not watch. At these moments, being well-trained in the art of going unnoticed can prevent all sorts of humiliating and damaging consequences from ever taking place. Furthermore, going unnoticed doesn't always mean just staying invisible. Picture yourself at a large cocktail party. Incredibly crowded, the room affords no opportunity for private conversation. Nevertheless, you are anxious to gush to your one close friend about the juicy gossip you have heard. How do you pull it off?
In public places, the exclusion of certain words--'keywords'--from conversation often means the difference between perking up an unfriendly ear and blending into the background noise. Professor Henry Gleitman and his colleagues have written in their book Psychology that, in a crowd, a person engaged in conversation may know that other conversations are happening all around, but he or she won't have a clue as to what the surrounding voices are actually saying. If amidst the din, however, a keyword, a word that the person has some attachment to, is mentioned, the person's brain will automatically filter out that word and reorient itself to pay attention to whoever said it. In N. Moray's oft-cited study on selective attention, experiments showed that individuals are remarkably attuned to their own names, able to hear them from across a crowded room. Moray has written that a person "may also detect other personally relevant stimuli--the name of a favorite restaurant, for example, or of a book the participant has just read."
Based on these observations, keeping your conversation private simply requires you to avoid the use of proper nouns and common phrases that might strike people as intriguing. An alternative to saying a boy's name out loud would be to describe him in terms of his position in the room or his appearance. But since phrases like 'that guy,' 'green shirt,' or 'punch bowl' might signal to a potential eavesdropper that you and your friend are discussing a specific person, less identifiable word combinations should be used instead, e.g. 'that gentleman in an emerald tunic orbiting the beverage table.' The more verbose the line, the better, since according to Moray, when people "hear speech, the sequence of sounds that reaches [their] ears is essentially unbroken, so it is up to us to decide where one word stops and the next begins," and people cannot parse large, unfamiliar words as efficiently as they can ordinary words.
From getting a drink in the middle of the night to slinking into the house well past curfew, certain situations demand stealth but offer no form of cover. For the pros, out-in-the-open scenarios like this can lead to all kinds of creative solutions, from building radar-dodging stealth planes to magicking a tank into a motorcycle. In lieu of true invisibility, modern stealth relies on one critical flaw in human cognition: people tend to have a much easier time noticing the activity they already expect. Give them something unexpected, and not only will they react more slowly, but they might not even react at all.
Try standing at the bathroom door just as your friend is about to walk out. When the door swings ajar, say "boo." There will be a sharp intake of breath, a subtle backwards recoil, a flinch. Now try the same trick again, but this time crouch low to the ground and pull your shirt over your head. A person's brain takes a much longer time trying to identify a short, seemingly headless creature than it takes to identify an upright human, and as the period of uncertainty lengthens, so does the magnitude of the fear. This time, your victim might even let loose a little yelp, the beginnings of a scream--to your ears, a far more satisfying sound than a mere gasp. To some extent, crouching or crawling actually weakens a would-be observer's ability to notice anything amiss, since an ordinarily conditioned human brain does not expect to see, and therefore reacts less efficiently to the sight of, a person moving so low to the ground.
In addition to the obvious benefits of being able to pull off a good scare or knowing how to slide in and out of social situations smoothly, learning to master the art of going unnoticed can sometimes offer deeper rewards. The euphoric rush of a risky sneak-by can serve as a means of excitement in itself, like a lesser version of skydiving or bungee jumping. The stigmas against stealth tactics run deep in that people generally frown upon anything underhanded, but this does not serve as an argument against using such tactics--only against getting caught. During a dangerously covert act, your tiny radar dot on the world disappears, and, as Jean Genet puts it in The Thief's Journal, "you feel yourself living." For one brief moment, your routines and responsibilities fade into the background noise. You become solitary, unaccounted for. That feeling alone can be worth the risk.
MATT SURKA B' 11 is a flower on the wall.