The Harmful Myth of Multitasking


June 7, 2021
myth of multitasking

When I was first applying for office-type jobs back in the late 00’s, I used to see the same thing pop up as a desirable trait on nearly every job description: ability to multitask effectively. Back then, I touted my ability to multitask. I would gladly nod my head and regale interviewers with a speech on how good I was at It.

But what I failed to realize then is that multitasking—rather than being a laudable skill of productive people—is actually the antithesis of productivity. Regular multitasking tends to make people less productive. What’s worse, regular multitasking is actually harmful to our cognitive abilities, as well as our bodies. For these reasons, multitasking should be avoided as much as possible, and replaced with focused work on one task at a time.

But let’s dive into what multitasking actually is, as well as what researchers have found about the way it affects us.

What Are We Doing When We Multitask?

Our superficial understanding of multitasking is that it’s a way of working where we can do two (or more) things at the same time. Using this superficial understanding has allowed us to become more attracted to the prospect of multitasking. It’s why so many job applications have listed it as a desired skill. And why not? After all, simple math tells us that 2 is twice as much as 1. So if we can do 2 things at once (or more), instead of just 1, why not do it? You’re doubling your productivity!

Not quite.

As it happens, actual multitasking is a much rarer thing than we think. Only a few things can be done at the same time—and those tend to be things that don’t require much of our cognitive resources—like walking and chewing. For nearly every work-related task, we’re not really doing two things at the same time. Instead we’re task-switching—that is, we’re switching our attention back and forth from one task to another.

So in any significant context, when we talk about multitasking, we’re almost always talking about task-switching. Unfortunately, task-switching has some notable costs. Those costs make it an almost entirely unappealing way to do work—unless you’re willing to sacrifice the quality of the tasks involved.

Below, we’ll look at two kinds of costs we incur when we practice multitasking.

What Multitasking Costs Us


One problem with multitasking is that, even though it seems like it would allow us to get more done, that tends to be an illusion. Over the years, we have learned that multitasking has costs—in most cases, ones that outweigh whatever benefits we think we’ll get.

Specifically, there are costs in the time investment and quality of our work. The output we provide is not as good as if we’d focused on one thing at a time. Also, as we saw above, running tasks in parallel involves task-switching, which adds on to the total time taken for all tasks involved.

Studies on multitasking have confirmed how jumping from one task to another affects our workflow:

Although switch costs may be relatively small, sometimes just a few tenths of a second per switch, they can add up to large amounts when people switch repeatedly back and forth between tasks. Thus, multitasking may seem efficient on the surface but may actually take more time in the end and involve more error….even brief mental blocks created by shifting between tasks can cost as much as 40 percent of someone’s productive time.

40%!!!!!! Using the standard 40-hour workweek, that adds up to just over 3 hours per day, 16 hours per week, and 800 hours per year stolen away by multitasking. If anything, that’s the opposite of productivity.

Other investigations into interruptions and task-switching have found that on average, it takes about 25 minutes for a person to get back to their original task once they switch to another. And once interrupted by another task, the average worker ended up doing 2.5 other tasks before getting back to what they were originally doing. It takes more time to do the same task, and more unfinished tasks are added to pile.

All of that creates stress, promotes errors, and drags work out longer. But consider this. The general thought is that it takes about 15 minutes to get into a flow state of doing focused work. So with the amount of interruptions and task-switching going on, it’s a wonder anyone gets any good work done at all.

Mental & Physical Health

But wait, there’s more! Multitasking is also harmful to your physical and mental health, as well as reducing your capacity to make decisions. Dr. Sandra Bond Chapman literally wrote the book on multitasking and the brain. She combed three decades’ worth of research to understand what trying to multitask does to our brains. Her conclusion is that:

Multitasking is a brain drain that exhausts the mind, zaps cognitive resources and, if left unchecked, condemns us to early mental decline and decreased sharpness. Chronic multitaskers also have increased levels of cortisol, the stress hormone, which can damage the memory region of the brain.

So, not only does multitasking affect the quality of your work. It also drags out the time it takes to complete that work. But it also negatively affects the most valuable tools you have for doing work: your brain and body.

What to Do Instead: Be Singular, Explicit, and Intentional

In the manufacturing world, there’s an ideal that many factories strive for when they’re setting up production: one piece flow. It describes a way of making products where one single item is completed before production begins on another one. It became popular when experts discovered how much waste was involved in batch production—where a whole group of products are built at the same time, and piles of half-finished “work in process” hang around the production space.

Managers found that errors, overproduction, downtime, and bottlenecks occurred regularly using batch production. So they began focusing on making one unit of product from start to finish. Paradoxically, it proved to be much more efficient. It’s not unlike what we find when look at multitasking vs. focused work on one task at a time.

As much as you can, one piece flow should be the ideal for your work: focus on one task from start to finish. Define what your task’s endpoint is, be sure it’s realistic for your time constraints, and work toward that until you’re done. If something interrupts you, and it’s important enough that you should stop doing what you were doing, shift focus intentionally. But don’t plan to balance both tasks at once.

Many times, we’re not even aware that we’re switching tasks. So a helpful practice to try is to be explicit with yourself when you’re beginning a new task, and what your endpoint on that task is. For example, imagine you’re working on one task, but you’re notified of an email you need to attend to. Ask yourself if you do really need to address it now. And if upon reflection, it is, then be explicit about changing tasks.

Make an explicit mental note to yourself that you’re stopping what you were working on to handle this email. Then read the email, decide what you’re going to do about it, and commit to working on it until you’ve done what you decided needed to be done. If you’re going to respond to the e-mail, then don’t work on something else until you’ve responded.

Ultimately, the one-piece flow idea is about not having a batch of unfinished work pulling at your finite energy and attention. Part of that is effectively deciding what’s important to do now. Another part is about being explicit and intentional about when you’re beginning and ending your work on tasks. The more you can develop that awareness and intentionality, the less you will engage in harmful multitasking behavior.

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1 year ago

Pomodoros have really been a great tool to increase my awareness of how prone I am to wander off into “multitasking.” For longform work, I simply commit, but grouping and handling categories of work (oh, email) is invaluable.

Frank Degenaar
1 year ago

I highly recommend a checklist of tasks that you can cycle through. Here’s a partial list of mine:

1. I start with notifications…
2. I then settle in for the “long haul” tasks…

… all the while working in Pomodoro blocks of 25-30 minutes.

Very little mental overhead not having to worry about doing several things simultaneously.

Checklists are essential for your sanity! They let you deal with categories of tasks and let you rest assured that nothing is falling through the cracks.


Daniel Parker
Daniel Parker
1 year ago

The multitasking myth is perpetuated by the denial of procrastination

1 year ago

oh workflowy 🙁 what’s with all these posts here lately that are so weirdly & obviously aimed at “DRIVING UP USER ENGAGEMENT!!!!11” and that whole community-blah? does anyone actually read this stuff? it feels like pinterest with words.

Frank Degenaar
1 year ago
Reply to  frank

Hello evil alter ego. I’ve been looking for you…

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