Multitasking in the Mind's Eye

The illusion of multitasking can lead to the reality of greater efficiency.

Posted Nov 23, 2018

Pixabay / CC0 Public Domain
Source: Pixabay / CC0 Public Domain

It’s common knowledge by now that multitasking is a grossly inefficient way to go about our daily business.  Study after study has shown that when we try to perform multiple tasks at the same time, we end up doing each of them more slowly and less accurately than if we had focused on one task at a time, which is all our attention actually permits us to do.  And while we’re not always aware of this inefficiency in our own efforts at multitasking, we notice it every day in other people.  Just this morning, for instance, when I stopped by a local fast food establishment to pick up breakfast, the headset-wearing cashier who approached me at the counter simultaneously took my order while completing an order in drive-thru, and on the way to pick up my food, restocked cups, removed the hash brown basket from the fryer, and set up three cups on the automatic soda dispenser.  I was not the least bit surprised, then, when I got to my car and discovered that my two ham biscuits and coffee had turned into a breakfast burrito and hot tea with a cookie on the side.  Multi-tasking is, quite simply, a bad idea. Our brains are wired to focus on one task at a time, and to try to do more than that is to fight against our own nature, neurally speaking.

And yet, fight we do.  Flying in the face of the prevailing wisdom about the fundamental inefficiency of multitasking, most of us spend our days performing multiple tasks at once because it simply makes us feel like we are getting more work done in a shorter span of time—it gives us the illusion of efficiency.  Given our insistence on multitasking, in spite of what the scientific evidence might say, it is comforting to learn that this illusion of efficiency might not be purely illusory after all.  New research from the Stephen M. Ross School of Business at the University of Michigan suggests that, while trying to perform many tasks at once is less efficient than taking them on one at a time, the perception that we are multitasking can, under certain circumstances, actually improve our performance.  Srna et al. presented people with a variety of activities that could be viewed as either single tasks or collections of multiple tasks, and compared their performance on the tasks on the basis of which way they perceived them.

In one study, 162 participants were divided into two groups and asked to watch and transcribe an educational video.  One group was told they would be completing two tasks simultaneously—a learning task and a transcribing test--while the other was told they would be working on a single learning task meant to test their learning and writing abilities.  In other words, while both groups were performing exactly the same activity, one group viewed their effort as multitasking, while the other considered themselves to be performing a single task.  When the results of the two groups’ note-taking sessions were compared, the people who perceived the work as multitasking outperformed the group that viewed it as a single task, transcribing more words, showing greater accuracy in their transcriptions, and scoring higher on an unannounced quiz at the end of the study.  The perception that they were multitasking significantly improved the first group’s efficiency, as compared to the second, single task group.

In another study, 237 participants were divided into two groups and asked to work on two puzzles—a 15 x 15 matrix of letters from in which they searched for words in a horizontal, vertical, and diagonal pattern, and an anagram task in which they constructed as many words as possible from a string of ten letters.  The “multitasking” group was told that the puzzles related to two different studies (perceptual and identification), while the “single-tasking” group was told that the two puzzles were both part of a single “perceptual-identification” study.  As with the video transcription study, the group that believed they were performing two tasks at once outperformed the group that believed they were performing a single task, coming up with more words in the time allotted.  Once again, the illusion of multitasking appeared to increase efficiency.

The researchers conjecture that the boost in efficiency they observed in the participants who perceived themselves as multi-tasking has to do with their relative engagement in the tasks with which they were presented.  Previous studies have demonstrated that people’s motivation for investing effort and attention increases with the difficulty of a given task.  The participants’ perception that they were multitasking may have increased their engagement with the tasks because they considered performing multiple tasks at once more challenging than performing one task at a time.  This conjecture was supported by physiological measures, in that the multitasking group exhibited greater pupil dilation during their work than did the single-tasking group, and pupil dilation has been shown to be associated with people’s “attentional and mental effort, processing load, and arousal.”  The perception that we are multitasking may increase our engagement with a task simply because we view it as a challenge.

Another possible reason for increased engagement in perceived multitasking is the cultural perception that multitasking is a desirable trait.  We may focus more attention on multitasking than on performing one task at a time simply because we wish to be perceived as good multitaskers.  Whatever the precise source for this increased engagement may be, the study suggests that we focus more attention on an activity when we perceive it to involve multitasking, as compared to the same activity when we perceive it as involving only a single task, and that this increase in focus makes us work more efficiently.

Srna et al. are quick to clarify that their study in no way contradicts the voluminous evidence that trying to perform several tasks simultaneously is far less efficient than performing one task at a time.  Multitasking, in the way most of us go about it, is still a bad idea.  When faced with an activity that can be broken down into component parts, however—balancing our checking account, for example, or creating a budget report at work—approaching it as a collection of tasks instead of as a single tedious job can sharpen our focus and give us an edge in the way we execute it.  While the reality of multitasking creates the false illusion of efficiency, the illusion of multitasking can make greater efficiency a reality.


Srna, Shalena et al. “The Illusion of Multitasking and Its Positive Effect on Performance.” Psychological science (2018): 956797618801013 .