About two months ago, a man inadvertently strolled past a “Do Not Enter” sign—and a TSA screener—at Newark Liberty International Airport. He was eventually deemed harmless, though not before part of a terminal was evacuated and hundreds of passengers were needlessly rescreened. Whoops. The incident was all the more embarrassing because another TSA screener had allowed a similar security breach just months earlier.
How can a grown man saunter past a TSA screener—whose entire job, needless to say, is to prevent such an occurrence? Psychologists have understood since the 1950s that observing a signal (e.g., a trespasser), when doing so requires sustained attention, becomes more difficult as the signal becomes less frequent. The likelihood at any given moment of someone attempting to enter a checkpoint via an exit was, in the TSA screener’s defense, relatively low. Remaining vigilant when signals are faint or subtle is more difficult still. One could quibble with the suggestion that entering an exit is a faint and subtle thing. Nonetheless, these men—who were neither wearing kangaroo suits nor playing accordions—doubtlessly resembled the other thousands of people who walked lawfully by each day.
Time matters too. I do not know whether the TSA screener in question was in the first or the fifth hour of her shift, but so long as she was not in the first, say, 20 minutes of it, she was probably not at her most alert. Vigilance is hard. Think of attention, as many psychologists have, as finite, a battery that loses voltage after continual exertion.
But what if attention isn’t finite at all? What if it’s the goal itself that weakens over time, and moreover, what if there’s a quick fix? Atsunori Ariga and Alejandro Lleras, psychologists at the University of Illinois, presented undergraduates with a standard vigilance task in which participants saw a series of vertical lines, appearing approximately twice per second, on a computer screen. The students had to press a key whenever they saw a line that was shorter than the others, an event that occurred about 10 percent of the time. In this study, as in dozens (if not hundreds) like it, participants’ ability to discriminate between the long and short lines decreased reliably over the course of the 40-minute study: vigilance suffered.
But in a second condition, researchers first had participants learn a set of digits. At three points during the vigilance task, a digit appeared on the screen and participants had to decide whether or not they’d studied it. Responding to this decision—another key press—took just two to three seconds. And yet these brief respites from line discrimination helped participants stay on task. Participants in this group showed no performance decline: they were just as vigilant after 40 minutes as they’d been at 10.
Because the respites from the primary task were so brief, the authors argue that it doesn’t make sense to think of them as “battery chargers.” Instead we might think of the breaks as preventing participants from becoming increasingly desensitized to the task at hand (or, as we say, from habituating to the goal).
Think of the real world implications of this research. Could solving a short puzzle every now and then keep employees on task? Maybe, but there are plenty of caveats. Breaks can’t occur so often that they become a part of the task itself. (Had the goal in the current study become “to detect short lines and to respond to digits,” the digit responses wouldn’t have been a respite from anything.) In addition, breaks need to be brief—that is, easy to disengage from. Checking Facebook or playing Angry Birds is still a bad idea. Breaks are only effective if the primary task can be easily resumed. And finally, of course, breaks—which are not caffeinated, and have no nutritional value—will be absolutely ineffectual against true fatigue.
Jobs demanding superhuman mindfulness from all-too-human minds are nothing new. The crow’s-nest watchman was perhaps the TSA scanner’s 19th-century equivalent. In Moby-Dick, Ishamel admits to being a woeful lookout. He goes on to warn ship owners, “Beware of enlisting in your vigilant fisheries any lad with lean brow and hollow eye; given to unseasonable meditativeness. … Beware of such a one, I say; your whales must be seen before they can be killed; and this sunken-eyed young Platonist will tow you ten wakes round the world, and never make you one pint of sperm the richer.” In the teeth of boredom, we are all young Platonists, given to unseasonable meditativeness. But it seems there are things we can do to prevent ourselves from day-dreaming, if only we can dream them up.