The Illusion of Multitasking
Despite the fact that multitasking impairs our judgment, many people hold on to the idea that it is a valuable ability to master in many contexts. Employers, especially, think it’s an enviable and needed “skill.” Indeed, consider that in the first month of 2019 alone, Monster.com, the global leader in online recruiting, posted more than three hundred thousand job descriptions that sought someone who could effectively multitask.
We think it’s a talent worth cultivating perhaps in part because multitasking just feels right. Researchers asked a group of volunteers in Columbus, Ohio, three times a day for one full month what they were doing and how they felt. The more the workers multitasked, the more they reported having fun. But multitasking is not the right course of action in all situations. Though they reportedly felt better, the more they multitasked, the less productive these workers were.
We multitask to try to get more done in a day, but the more often we do it, the less effective we are. Besides its feeling fun, why do we continue to do something that works so poorly?
To gain some traction on this question, let’s look to children. Back when I taught Introduction to Psychology, every year I would show a video clip of an experiment to my students. In it, you see a smiling adult sitting on a chair designed for hips half her size, at a table barely higher than a tall stair. Next to her sits a towheaded four-year-old boy in a puffy hoodie with bright, curious eyes, cheeks still plump from a love of whole milk at snack time. On a tray in front of the child, the adult counts out five candies wrapped in colorful cellophane and arranges them in an evenly spaced single row. She takes another five candies and places each below one already on the tray, forming a second identical, evenly spaced row. The adult asks the boy if the first row has more candies than the second row, if the first row has fewer candies than the second, or if they have the same number. The boy sits through this whole preparation with his head propped up on his fist, elbow on the table, his eyes darting from her face to the candies, keeping a careful eye out for a goodie that might be ripe for his plucking. He answers correctly that the two rows have the same number. But then, as the boy watches quite keenly, the adult increases the spacing between the candies in the second row. She asks her question again, and this time the boy says that there are more candies in the second row.
Though any adult watching this knows the number has not changed, the little boy equates the visual experience of greater length with greater quantity. Confusing space and number is almost an inherent part of our experience as people. Clever developmental psychologists have discovered ways of testing infants’ expectations about how the world works. They know that babies enter this life with the understanding of what more is, and that more can describe what we see and what we hear. French scientists tested about one hundred infants, some no more than eight hours old. The researchers played a recording of adults babbling syllables to the infants, and at the same time showed them a colorful line. Not high art, but a visual image that babies this young could actually see and enjoy. Some of the babies heard many syllables in a row and saw a long line. Other babies heard just a few syllables and saw a short line.
The researchers hypothesized that these babies would pick up on the patterns they’d just been exposed to. To test their predictions, the researchers paid particular attention to how the babies reacted next.
In the next two tests, the experimenter made some changes. Babies who had heard many babbles now only heard a few. Babies who had heard just a few now heard many. Like before, a line appeared on the screen at the same time as they heard the sounds. One time, this line was long; another time, it was short. The question was whether the infants would react differently to the test pairing that changed for them relative to “the pairing rules” they learned in the earlier session. Researchers who study babies know that newborns look at things that they find new and surprising, so if they looked longer at the screen, these scientists knew that the pairing of sounds and visuals was unexpected.
What this team found was that the babies looked longer when the auditory and visual pairings changed. Greater length went with greater number, in these babies’ brand-new brains. And these tiny humans were surprised when they experienced a mismatch.
Even with many years of life experience under our belts, we continue to confuse physical magnitude with numerical value, and this illusion is something that companies have used to their advantage to grab hold of our wallet. In 2011, Kraft made a dramatic change to its packaging of Nabisco Premium saltines to curb snackers’ experience of staleness. In place of four sleeves of crackers, Kraft introduced its “Fresh Stacks” packages: eight (smaller) sleeves instead of the usual four. The saltines held constant at the same price point, but an astute consumer might have noticed that the entire Fresh Stacks box contained 15 percent fewer crackers than the original. You might think that value-conscious consumers would be up in arms, or at least less interested in buying the item, which now cost more per unit. But no. Two years before the packaging switch, Kraft earned $208 million from cracker sales; in the year after the switch, Kraft earned a whopping $272 million. Of course, inflation happens and marketing strategies change, but the new packaging was one of the most radical changes Kraft had ever made, simultaneous with one of the largest gains. And that trend continued. For the fifty-two weeks ending May 17, 2015, Nabisco Premium was the leading saltine cracker brand in the United States.
Choosing more even when it means actually getting less is a common experience, and one that might explain why we believe that multitasking increases productivity. The reason for our overreliance on a generally ineffective tactic might be the same reason that marketers were able to rejuvenate consumers’ interest in repackaged saltine crackers. Just as the visual illusion of more seems better, doing more with our time just feels right—though in reality it isn’t always the right decision.
Stuck in the Illusion
We have trouble surmounting our impulse to capitalize on the illusory appeal of multitasking for the same reasons that children believe a row of five candies spread wide contains more than the row of five candies tightly bunched. We struggle to override our instincts.
Children fall for the experimenter’s trick of changing the spacing between candies despite being capable of doing math. In fact, well after most kids can count to one hundred and are able to add and subtract, they will confuse greater length for greater quantity when the experimenter spreads one row of candies out wider. They have difficulty overcoming the visual illusion they experience in the present moment.
The same is true of adults. And, in fact, it’s something you can experience right now. On this page, you’ll see a diagram of a home. On two of the corners is a bold black line. Which is longer? Which is shorter? You may have seen a version of this figure before. I have—and yet it still manages to deceive me, as it might you. The lines are in fact the same length, but that’s not how we see it. Time and time again, the line on the right appears longer than the one on the left. That’s because the outlines of the walls and windows act as flankers that distort our perception of distance. The edges of the wall on the right create a context that tricks our eyes into seeing it as longer than it really is. The edges of the window on the left contract our experience of that line’s length. Despite knowing in our brains that they are the same, we see with our eyes two lines that are different from each other.