# Does Multitasking Work? The Hidden Cost of Switching Work · 6 min read · updated 2026-10-30 > Most multitasking is really switching, and every switch costs time and accuracy. What the research shows, who the rare supertaskers are, and what helps. ## The short answer Mostly not. For tasks that need thought, what feels like multitasking is rapid switching, and every switch costs time to refocus, increases mistakes and delays finishing each task. Studies find switching can eat a large share of productive time, and people who multitask the most are often worse at ignoring distractions. Only a tiny minority, about 2.5% in one study, handle two demanding tasks without a drop. Answering emails during a meeting, checking messages while writing a report, scrolling a feed while half-watching a film: it feels efficient, as if two things are getting done at once. For most tasks that take thought, they aren’t. Your brain switches between them, and each switch costs a little time to get back up to speed. The costs are small enough to feel like nothing and large enough, over a day, to matter a great deal. Set the switches in the toy at the top and watch the minutes add up. ## Two things at once, or one after another? Some things really can be done together: walking and talking, or folding laundry while listening to music. One of them runs on autopilot, so it barely needs attention. But two tasks that both need attention, like reading and writing, or listening to a colleague and replying to an email, can’t truly run side by side. What feels like doing both is your attention hopping back and forth between them, so quickly that you don’t notice the gaps. The giveaway is what happens to the quality. Try to follow a conversation while reading a message, and you’ll find you’ve missed a sentence of one or the other. That’s not carelessness. It’s the bottleneck that sits at the centre of how attention works. ## The switch cost Every time you switch, you have to drop one set of goals and rules and pick up another: where was I, what was I about to do, what does this need? Psychologists call the time this takes the **switch cost**. In a series of experiments published in 2001, Joshua Rubinstein, David Meyer and Jeffrey Evans had people switch between tasks such as solving maths problems and sorting shapes. Switching always took longer than sticking with one task, and the cost grew as the tasks got more complicated or less familiar. Each switch cost only fractions of a second in the lab. Meyer has estimated that in real work, with constant switching between complex tasks, the losses can reach as much as 40% of someone’s productive time. In real offices, the cost of getting back in is much longer than a lab switch. The researcher Gloria Mark has studied people at work and found that after an interruption, it can take a long time, often more than twenty minutes, before people return to what they were doing, because one interruption tends to lead to another. ## The cost you don’t see Switching doesn’t only add time. It also delays everything. Do two half-hour tasks one after another and the first is finished at 30 minutes. Switch between them and the first isn’t finished until near the very end. If the first was the one someone was waiting for, switching made them wait almost twice as long, for no gain at all. There’s also the cost of mistakes. When attention is split, people are more likely to miss details, and checking and fixing errors takes more time again. And there’s what the researcher Sophie Leroy calls *attention residue*: when you leave a task unfinished, part of your mind stays on it, so you do the next task less well. Her experiments found people performed worse on a new task when they’d been pulled away from an unfinished one. ## A morning, two ways Picture a morning with a report to write and an inbox that pings about every ten minutes. In the first version, you answer each email as it arrives. Each one takes three minutes, but getting back into the report takes another five, because you have to reread where you were and remember what you meant to say next. Over three hours, eighteen emails cost you about 54 minutes of replying and another 90 of getting back in. The report gets about half of the morning, in broken pieces, and it shows. In the second version, you turn the notifications off, write for ninety minutes, then answer all the emails in one forty-five-minute block. Then you write for another forty-five minutes. The same emails get answered, slightly later. The report gets more than two hours of continuous attention, and you finish it. The numbers are illustrative, but the shape is what studies find: the replies take the same time either way. What changes is everything around them. ## Why we keep doing it If it’s so costly, why is it so tempting? Partly because switching feels productive. Each email answered is a small, visible win, and it’s satisfying in a way that slow progress on a hard task isn’t. Partly because new things grab attention, so a fresh notification is hard to ignore. And partly because of social pressure: in many workplaces, fast replies are taken as a sign of being good at the job, even when they come at the cost of the work that matters. Knowing this doesn’t make the urge go away. It does make it easier to set up your day so that you have to resist it less often. ## Are some people good at it? Some people feel they are. A 2009 study by Eyal Ophir, Clifford Nass and Anthony Wagner at Stanford compared people who said they multitasked heavily with media against those who rarely did. The heavy multitaskers were, if anything, *worse* at ignoring irrelevant information and at switching between tasks. There is a very small group who seem to manage it. *(An interactive illustration belongs here. Try it on the page: https://cognosc.com/blog/does-multitasking-work)* Feeling good at multitasking, in other words, isn’t the same as being good at it, and the people most confident in their skill are often the ones it most misleads. ## In class and on the road Two settings show what’s at stake. **Learning.** In a 2013 study, Faria Sana and colleagues had students attend a lecture with laptops. Those asked to do a few unrelated online tasks during the lecture scored lower on a test of it afterwards. So did students who weren’t multitasking themselves but could see a classmate’s screen. Distraction spreads. **Driving.** Driving feels automatic, but it isn’t, especially when something unexpected happens. *(An interactive illustration belongs here. Try it on the page: https://cognosc.com/blog/does-multitasking-work)* ## Working with fewer switches You don’t need perfect focus. You need fewer switches, and better ones. - **Batch similar tasks.** Answer emails in two or three blocks a day instead of as they arrive. Make calls in a row. - **Turn off notifications** for the length of a piece of focused work. Each one invites a switch, even if you don’t act on it. - **Finish the thing someone’s waiting for first.** Switching delays everything; doing one thing at a time gets each one out sooner. - **Leave yourself a note** when you must switch: where you were and what was next. It shortens the time to get back in and reduces the residue. - **Protect blocks of deep work.** An hour or two with no meetings and no messages does more than a day of fragments. - **Keep the phone out of reach.** Studies suggest that even a phone face down on the desk can draw some attention away from the task. - **Let easy tasks pair up.** Folding laundry while on a call, or walking while listening to a podcast, is fine. Save your attention for things that need it. ## When switching is the job Some jobs are made of interruptions: a nurse on a ward, a parent of small children, a support desk. In those, single-tasking isn’t on offer. What helps there is reducing the cost of each switch: checklists that hold your place, clear handovers, writing things down so that your memory isn’t doing the job of a notebook. The principle is the same. Every time you leave a task, make it easier to come back. ## Test yourself The free [how learning works test](/test/learning) covers how attention and practice really work, and the [psychology myths test](/test/psychology) has more beliefs about the mind to check, including the one about doing two demanding things at once. ## What to remember - Two tasks that both need attention can’t truly run at once: your attention switches between them. - Each switch costs time to refocus, and the costs add up over a day. - Switching also delays everything: each task finishes later than if you’d done it alone. - Heavy multitaskers tend to be worse at filtering distractions, not better. - Batch similar tasks, turn off notifications and finish one thing before starting the next. ## Questions people ask ### Is multitasking actually possible? For a task on autopilot plus a task that needs thought, such as walking and talking, yes. For two tasks that both need attention, such as writing an email during a meeting, the brain switches between them rather than doing both at once, and each switch costs time and accuracy. ### How much time does task switching waste? It depends on the tasks, but the costs add up. In experiments, every switch adds a delay while you reorient, and the psychologist David Meyer has estimated that heavy switching can cost as much as 40% of productive time. Interruptions also make it slower to get back into deep work. ### Are women better at multitasking than men? The evidence for a meaningful difference is weak and mixed. Some studies find small differences on particular tasks, others none. What’s consistent is that almost everyone, of any gender, performs worse when switching between two demanding tasks than when focusing on one. ### What is attention residue? A term from the researcher Sophie Leroy for the part of your attention that stays stuck on a previous task after you switch. If you leave a task unfinished, thoughts about it linger and reduce how well you perform the next one. Finishing tasks or noting where you left off reduces it. ### Does listening to music while working count as multitasking? It can. Instrumental music in the background is often fine for routine work. Music with lyrics tends to compete with reading and writing, because both use language. For demanding work, quiet or music without words is usually the safer choice. ## Sources and further reading - Rubinstein, J. S., Meyer, D. E. and Evans, J. E. (2001). Executive control of cognitive processes in task switching. Journal of Experimental Psychology: Human Perception and Performance, 27(4), 763–797. - Ophir, E., Nass, C. and Wagner, A. D. (2009). Cognitive control in media multitaskers. PNAS, 106(37), 15583–15587. - Watson, J. M. and Strayer, D. L. (2010). Supertaskers: Profiles in extraordinary multitasking ability. Psychonomic Bulletin & Review, 17(4), 479–485. - Strayer, D. L. and Johnston, W. A. (2001). Driven to distraction: Dual-task studies of simulated driving and conversing on a cellular telephone. Psychological Science, 12(6), 462–466. - Leroy, S. (2009). Why is it so hard to do my work? The challenge of attention residue when switching between work tasks. Organizational Behavior and Human Decision Processes, 109(2), 168–181. - Sana, F., Weston, T. and Cepeda, N. J. (2013). Laptop multitasking hinders classroom learning for both users and nearby peers. Computers & Education, 62, 24–31. --- Canonical page: https://cognosc.com/blog/does-multitasking-work From Cognosc (https://cognosc.com): free tests, articles and an AI tutor that has you reason things through.