Читать книгу The Invisible Gorilla: And Other Ways Our Intuition Deceives Us - Christopher Chabris - Страница 8

Do you remember the first major international incident of George W. Bush’s presidency? It happened less than a month after he took office, on February 9, 2001.²⁰ At approximately 1:40 p.m., Commander Scott Waddle, captaining the nuclear submarine USS Greeneville near Hawaii, ordered a surprise maneuver known as an “emergency deep,” in which the submarine suddenly dives. He followed this with an “emergency main ballast tank blow,” in which high-pressure air forces water from the main ballasts, causing the submarine to surface as fast as it can. In this kind of maneuver, shown in movies like The Hunt for Red October, the bow of the submarine actually heaves out of the water. As the Greeneville zoomed toward the surface, the crew and passengers heard a loud noise, and the entire ship shook. “Jesus!” said Waddle. “What the hell was that?”

His ship had surfaced, at high speed, directly under a Japanese fishing vessel, the Ehime Maru. The Greeneville’s rudder, which had been specially reinforced for penetrating ice packs in the Arctic, sliced the fishing boat’s hull from one side to the other. Diesel fuel began to leak and the Ehime Maru took on water. Within minutes, it tipped up and sank by its stern as the people onboard scrambled forward toward the bow. Many of them reached the three lifeboats and were rescued, but three crew members and six passengers died. The Greeneville received only minor damage, and no one onboard was injured.

What went wrong? How could a modern, technologically advanced submarine, equipped with state-of-the-art sonar and manned by an experienced crew, not detect a nearly two-hundred-foot-long fishing boat so close by? In attempting to explain this accident, the National Transportation Safety Board’s fifty-nine-page report exhaustively documents all of the ways in which the officers failed to follow procedure, all of the distractions they faced in accommodating a delegation of civilian visitors, all of the errors they made along the way, and all of the miscommunication that contributed to poor tracking of the Ehime Maru’s actual position. It contains no evidence of alcohol, drugs, mental illness, fatigue, or personality conflicts influencing the crew’s actions. The report is most interesting, however, for the crucial issue it does not even attempt to resolve: why Commander Waddle and the officer of the deck failed to see the Ehime Maru when they looked through the periscope.

Before a submarine performs an emergency deep maneuver, it returns to periscope depth so the commander can make sure no other ships are in the vicinity. The Ehime Maru should have been visible through the periscope, and Commander Waddle looked right toward it, but he still missed it. Why? The NTSB report emphasized the brevity of the periscope scan, as did Dateline NBC correspondent Stone Phillips: “…had Waddle stayed on the periscope longer, or raised it higher, he might have seen the Ehime Maru. He says there is no doubt he was looking in the right direction.” None of these reports consider any other reasons why Waddle could have failed to see the nearby vessel—a failure that surprised Waddle himself. But the results of our gorilla experiment tell us that the USS Greeneville’s commanding officer, with all his experience and expertise, could indeed have looked right at another ship and just not have seen it. The key lies in what he thought he would see when he looked: As he said later, “I wasn’t looking for it, nor did I expect it.”²¹

Submarines rarely surface into other ships, so don’t lose sleep over the prospect on your next boat trip. But this kind of “looked but failed to see” accident is quite common on land. Perhaps you have had the experience of starting to turn out of a parking lot or a side road and then having to stop suddenly to avoid hitting a car you hadn’t seen before that moment. After accidents, drivers regularly claim, “I was looking right there and they came out of nowhere…I never saw them.”²² These situations are especially troubling because they run counter to our intuitions about the mental processes involved in attention and perception. We think we should see anything in front of us, but in fact we are aware of only a small portion of our visual world at any moment. The idea that we can look but not see is flatly incompatible with how we understand our own minds, and this mistaken understanding can lead to incautious or overconfident decisions.

In this chapter, when we talk about looking, as in “looking without seeing,” we don’t mean anything abstract or vague or metaphorical. We literally mean looking right at something. We truly are arguing that directing our eyes at something does not guarantee that we will consciously see it. A skeptic might question whether a subject in the gorilla experiment or an officer chasing a suspect or a submarine commander bringing his ship to the surface actually looked right at the unexpected object or event. To perform these tasks, though (to count the passes, pursue a suspect, or sweep the area for ships), they needed to look right where the unexpected object appeared. It turns out that there is a way, in a laboratory situation at least, to measure exactly where on a screen a person fixates their eyes (a technical way of saying “where they are looking”) at any moment. This technique, which uses a device called an “eye tracker,” can provide a continuous trace showing where and for how long a subject is looking during any period of time—such as the time of watching the gorilla video. Sports scientist Daniel Memmert of Heidelberg University ran our gorilla experiment using his eye tracker and found that the subjects who failed to notice the gorilla had spent, on average, a full second looking right at it—the same amount of time as those who did see it!²³