The Invisible Gorilla: And Other Ways Our Intuition Deceives Us. Christopher Chabris
The effects of inattention are further amplified by any device or activity that takes attention away from what we are trying to do. Such devices and activities were rare in the BlackBerryless, iPhone-free, pre-GPS past, but they’re common today. Fortunately, accidents are still rare, because most of the time, nothing unexpected happens. But it is those rare unexpected events that matter. People are confident that they can drive and talk on the phone simultaneously precisely because they almost never encounter evidence that they cannot. And by “evidence” we don’t mean a news story about accident rates or a safety institute’s latest report, or even a story of a friend who zoned out while driving and almost hit something. We mean a personal experience, like a collision or a near miss, that was unambiguously caused by a depletion of attention and that cannot be explained away as the other person’s fault (a rationalization we are as good at making as we are at overestimating our own levels of attention). We will almost never be aware of the more subtle evidence of our distraction. Drivers who make mistakes usually don’t notice them; after all, they’re distracted.
The problem is that we lack positive evidence for our lack of attention. That is the basis of the illusion of attention. We are aware only of the unexpected objects we do notice, not the ones we have missed. Consequently, all the evidence we have is for good perception of our world. It takes an experience like missing the chest-thumping gorilla, which is hard to explain away (and which we have little incentive to explain away), to show us how much of the world around us we must be missing.
If the mechanisms of attention are opaque to us, how can we eliminate inattentional blindness so that we can be sure to spot the gorilla? The answer isn’t simple. In order to eliminate inattentional blindness, we would effectively have to eliminate focused attention. We would have to watch the gorilla video without bothering to focus on counting passes or even to focus on what we found interesting in the display. We would have to watch the display without expectations and without goals. But for the human mind, expectations and goals are inextricably intertwined with the most basic processes of perception and are not readily extinguished. Expectations are based on our prior experiences of the world, and perception builds on that experience. Our experience and expectations help us to make sense of what we see, and without them, the visual world would just be an unstructured array of light, a “blooming, buzzing confusion” in the classic words of William James.49
For the human brain, attention is essentially a zero-sum game: If we pay more attention to one place, object, or event, we necessarily pay less attention to others. Inattentional blindness is thus a necessary, if unfortunate, by-product of the normal operation of attention and perception. If we are right that inattentional blindness results from inherent limits on the capacity of visual attention, it might be impossible to reduce or eliminate it in general. In essence, trying to eliminate inattentional blindness would be equivalent to asking people to try flying by flapping their arms really rapidly. The structure of the human body doesn’t permit us to fly, just as the structure of the mind doesn’t permit us to consciously perceive everything around us.
The issue of how best to allocate our limited attention relates to a larger principle of attention. For the most part, inattentional blindness isn’t a problem. In fact, it is a consequence of the way attention works; it is the cost of our exceptional—and exceptionally useful—ability to focus our minds. Focused attention allows us to avoid distraction and use our limited resources more effectively; we don’t want to be distracted by everything else around us. Most drivers follow the rules of the road, most doctors don’t leave guidewires in patients, most fishing vessels aren’t floating right above submarines, most planes aren’t guided in to land right on top of other planes, most cops don’t viciously beat suspects, and most world-class violinists don’t play in the subway. And gorillas rarely saunter through basketball games. Unexpected events are unexpected for a good reason: They are rare. More important, in most cases, failing to spot the unexpected has little consequence.
Attention Writ Large
The illusion of attention affects us all in both mundane and potentially life-threatening ways—it truly is an everyday illusion. It contributes to everything from traffic accidents and airplane cockpit displays to cell phones, medicine, and even subway busking. As the gorilla experiment has become more widely known, it has been used to explain countless failures of awareness, from the concrete to the abstract, in diverse domains. It’s not just limited to visual attention, but applies equally well to all of our senses and even to broader patterns in the world around us. The gorilla experiment is powerful because it forces people to confront the illusion of attention. It provides an effective metaphor precisely because the illusion of attention has such broad reach. Here are some examples:50
A trainer uses it to show people how they can miss safety infractions that are right in front of them.
A Harvard professor uses it to explain how discriminatory practices in the workplace can go unnoticed even by intelligent, fair-minded individuals.
Antiterrorism experts cited it to explain how Australian intelligence officials could have missed the presence in their own country of the Jemaah Islamiyah group, which was responsible for the 2002 Bali bombings that killed 202 people.
A weight-loss website compares the unseen gorilla to an unplanned snack that can ruin your diet.
Promoter of the paranormal Dean Radin likens the inattentional blindness of our subjects to the failure of scientists to see the “reality” of ESP and other extrasensory phenomena.
A high school principal uses inattentional blindness to explain how teachers and administrators often fail to notice bullying.
An Episcopal priest used it in a sermon to explain how easily people can miss evidence of God all around them.
A British ad campaign encouraged drivers to watch for bicyclists by creating a television and viral Web advertisement based on our video, with the chest-thumping gorilla replaced by a moonwalking bear.
Within the realm of visual perception, noticing suffers from even more limitations than the ones we have discussed so far. For example, it is hard to look for multiple things at once, to distinguish similarlooking objects, and to remain vigilant over long periods of time performing the same task. Our underappreciation of these constraints can have dire consequences for our safety and security. We expect airport baggage scanners to spot weapons in luggage, but they regularly fail to notice contraband items planted by authorities during tests of security procedures. The task of security scanners is much like the task of radiologists (though the training is, shall we say, much less extensive), and it is difficult if not impossible to see everything in a briefly viewed image. That’s especially true given that the things being searched for are rare.51
Similarly, we expect lifeguards at swimming pools to notice anyone in danger of drowning, but this is a false sense of safety brought on by the illusion of attention. Lifeguards have the nearly impossible task of scanning a large expanse of water and detecting the rare event of someone drowning.52 The difficulty of their task is exacerbated because swimmers regularly do things that look like drowning but aren’t, such as swimming under water, lying on the bottom of the pool, splashing frantically, and so on. Lifeguards take regular breaks, change their viewing stations repeatedly during shifts, and take many other steps to maintain their vigilance, but vigilance, besides being subject to its own limitations, cannot eliminate inattentional blindness. The lifeguards simply cannot see everything, but the illusion of attention makes us believe they will.
Only becoming aware of the illusion of attention can help us to take steps to avoid missing what we need to see. In some cases, like lifeguarding, technological innovations such as automated scanning could help. Without awareness of our limitations, though, technological intervention can hurt. Head-up displays might improve our ability to navigate and to keep our eyes on the road, but they might impair our ability to detect unexpected