The myth of multitasking

(I came across this old post of mine from back in 2011 that I thought might be of interest to those who had not seen it.)

Since I work at a university and am around young adults all the time, I have long been aware that young people today are avid consumers of multimedia, who are adept at emailing, texting, listening to mp3 players, surfing the web, checking up on Facebook, etc. It seems like they are quite proficient at multitasking.

I have always been a poor multitasker. I cannot read or do any work that requires serious thinking if I can hear conversation or loud noises in the background. I have found that I cannot even listen to music in the background when reading. But I know people who seem to thrive on that kind of ambient sound and even deliberately go to coffee shops to do work such as grading papers or writing, things that would be impossible for me.

I had thought that my lack of ability to multitask was partly due to being old and not acquiring these skills while young, similar to my slow reaction time when playing video games (which results in being destroyed when playing them with my children) and my inability to manipulate my thumbs dexterously enough to use the small keys on cell phones without making numerous mistakes.

I thought my poor multitasking skills may also be due to a cognitive disability, similar to the one that prevents me from ever seeing the hidden 3-D images in those so-called autostereogram (‘Magic Eye’) pictures that were such a rage a few years ago. The Sunday papers used to have one and my daughters would look briefly at it and say, “Oh, look at the dolphins” or whatever it was that day whereas, despite my strenuous efforts at staring using all the recommended tricks, all I saw were colored dots and wiggly lines. I later learned that some people never see the hidden image, due to some feature of their visual-cognitive brain function. It was not reassuring to discover that I have a defective brain, and that there is no warranty.

But a study by Stanford researchers Eyal Ophira, Clifford Nass, and Anthony D. Wagner titled Cognitive control in media multitaskers and published in 2009 the Proceedings of the National Academy of Sciences seems to indicate that hardly anyone can really multitask and they are only deluding themselves that they can.

In an interview with the PBS program Frontline, lead researcher Clifford Nass said that it is possible to multitask certain things if those require different parts of the brain. For example, one might be able to cook and keep an eye on the children, or do gardening while listening to music or drive while talking. But classical psychology says that when it comes to doing more than one task that requires similar cognitive abilities, the brain simply cannot do that. What people do is try to rapidly switch their attention from one task to the next.

Nass and his colleagues hypothesized that to carry out successful multitasking of this latter sort required three distinct skills. One is the ability to filter, to detect irrelevancy, to be able to quickly distinguish between those things that are important and those that are not important. The second is the rapidity with which they could switch from one task to the next. The third is a greater ability to sort and organize the information in the brain so as to keep track of the results of their different tasks.

The researchers expected to find that people who were ‘high multitaskers’, i.e., people who tend to do multiple things, would be very good at least in one of those areas when compared to the ‘low multitaskers’, i.e., people like me who have to do things sequentially. What they were surprised to find was that the high multitaskers were terrible in all three areas.

So we know, for example, that people’s ability to ignore irrelevancy — multitaskers love irrelevancy. They get distracted constantly. Multitaskers are very disorganized in keeping their memory going so that we think of them as filing cabinets in the brain where papers are flying everywhere and disorganized, much like my office.

And then we have them being worse at switching from one task to another. … It’s very troubling. And we have not yet found something that they’re definitely better at than people who don’t multitask.

There is a serious cost to this. The researchers say that trying to multitask leads to deficiencies in analytical reasoning because people don’t stick to one thing long enough to think it through but instead shift to another task, thus thinking in fragments.

We worry about it, because as people become more and more multitaskers, as more and more people — not just young kids, which we’re seeing a great deal of, but even in the workplace, people being forced to multitask, we worry that it may be creating people who are unable to think well and clearly.

And it seems as if simply telling them that trying to multitask is bad does not have any effect.

One would think that if people were bad at multitasking, they would stop. However, when we talk with the multitaskers, they seem to think they’re great at it and seem totally unfazed and totally able to do more and more and more.

[V]irtually all multitaskers think they are brilliant at multitasking. And one of the big new items here, and one of the big discoveries is, you know what? You’re really lousy at it. And even though I’m at the university and tell my students this, they say: “Oh, yeah, yeah. But not me! I can handle it. I can manage all these”.

One of the biggest delusions we hear from students is, “I do five things at once because I don’t have time to do them one at a time.” And that turns out to be false. That is to say, they would actually be quicker if they did one thing, then the next thing, then the next. It may not be as fun, but they’d be more efficient.

One interesting finding in the study was that there were no gender differences, which goes against the myth that women are either naturally good multitaskers or become so because of the multiple roles imposed on them by society, such as caregiver, housekeeper, breadwinner, etc. This may be an illusion that arose from the fact that the multiple tasks that they have traditionally had to do (keeping an eye on the children while cooking or cleaning the house and listening to the radio) largely involved different parts of the brain and thus did not pose any serious cognitive conflicts.

The big challenge will be how to wean people away from thinking they can multitask. We are not doing them any favors by letting them continue to delude themselves.


  1. No Respect says

    I bet that those dimwits Eyal Ophira, Clifford Nass and Anthony D. Wagner falsified their results to feel better about not being able to multitask themselves.

  2. sonofrojblake says

    There are some charmingly dated details in this. ” listening to mp3 players”, “inability to manipulate my thumbs dexterously enough to use the small keys on cell phones”. I remember when mp3 players were a thing and phone had more than three or four physical buttons on them, and all this was fields, get off my lawn, and so on.

    My go to example when it comes to demonstrating multitasking is juggling -- I can stand in front of you and juggle a dozen different patterns, including the fiendish Mills’ Mess, while holding a conversation with you and looking you directly in the eye. This would appear on its face near impossible as most people struggle to juggle three balls at all without fierce concentration, but once you’ve got the basic motor skills in place, and assuming your peripheral vision is half-decent, the experience is as though the arms are operating themselves leaving the brain free to converse and the eyes fairly free to look elsewhere (as long as you’ve peripheral awareness of the balls’ positions). That’s three balls, though -- I can only maintain eye contact with four balls if I stick to a straightforward fountain, and if you want to see me do a cascade with five, I’m going to have to look away from you completely. I do know someone who can cascade five and maintain eye contact, but I’m not convinced he’s ever dropped anything in his life…

    I’m consistently amazed at the ability of musicians to play an instrument -- almost any instrument -- and sing at the same time. One of the greatest examples of that can be seen here (anyone with any experience of acoustic guitar will tell you that what Lindsey Buckingham is doing with the guitar alone here is near-miraculous multitasking on its own, aside from the fact he’s managing to sing as well).

    Re: weaning people off -- you won’t. Why? One word: capitalism. Our whole bloody system is built on the idea we must, must, must do more with less. What you’re suggesting is getting people to admit that they can’t do everything -- and if they do that, the boss will hire someone who can (or who can convincingly pretend they can…) instead.

    The real big challenge will be weaning managers off the idea that working more and more and more and doing more things simultaneously is desirable or productive.

  3. says

    We multitask always. We walk and chew gum, talk and breathe, drink and breathe, listen and walk, poop while thinking what we are doing later tonight, etc. We are parallel processors by nature -- for example we process sound and vision asynchronously at different speeds and our brains present a synchronized experience.
    Above and beyond that are cognitive processes that can parallelize but depend on common parts of our brain (e.g.: memory to map seen things to names) we can do some of that more or less well, individually. People with dementia don’t like complexity because complex problems involve more parts of the brain, potentially including degraded capabilities.
    It would seem to me that our ability to multitask would be idiosyncratic and depend on the tasks and what brain capabilities they depend on. It’s gonna be a lot more complicated than simple experiments would have us believe. For example, driving a car and txting on a phone might be easier than txting on a phone and singing karaoke. Richard Feynman describes some experiments he did trying to see what affected his ability to count accurate seconds to sixty -- running up and down stairs was no problem but dialing a telephone was (if I recall correctly). It makes sense that running and counting tasks might parallelize while two counting tasks might not. (Though drummers like Ginger Baker and John Bonham can produce different beat counts with their feet from their hands, when they aren’t dead) we don’t know what are learned behaviors and what are consciously controlled functions.

    Also -- in computing we recognize a difference between time-slicing and parallel processing. “Multitasking” refers to the apparent performance of simultaneous operations but it could be a mix of parallelism with synchronization and time-slicing. Modern CPUs even do predictive multithreading -- starting down process steps that may not be executed, then pruning them later or evaluating them optimistically. It is quite possible -- even likely -- that our brains do similar things, e.g: “exit ramp coming up, think a bit about how to slow down and turn” and “well ok not that exit” -- again properties that degrade in dementia patients and may indicate different parts of the brain parallelizing.

    That’s all a long way of saying I think those social scientists are violently oversimplifying.

  4. Jazzlet says

    I don’t multitask as well as I did, I could produce a complicated meal for guests while chatting with them and with little reference to the recipes, maybe a timeline written on the white board if there were a lot of dishes to be cooked simultaneously. Thee days I have to concentrate, and have the recipes open as well as having the timeline, but I put that down to initially gabapentin, now pregabalin and the opioids I take as they certainly slow my thinking down. However I can still do thing like making bread products and reading or soaking a particularly grubby bit of floor and posting a comment here simultaneously 😉 though clearly the researchers woldn’t count that as multitasking.

  5. Deepak Shetty says

    One interesting finding in the study was that there were no gender differences,

    YES! Finally a response to my spouse.
    With regards to cooking -- While cooking I can only do it serially -- one task at a time. This is in marked contrast to how my parents , grandparents , aunts and uncles cook who seem to always have multiple items going on -simultaneous cutting /chopping/cooking/cleaning/frying. I guess the difference is that they were trained on the job by their parents whereas I learnt from my roommates (The lessons were a.) Either eat what i cook or cook yourself and b.) It is not important to cook well , it is only important to learn how to eat what one cooks)

    In terms of work too (software programming) -- multitasking makes everything worse , but there is no alternative is what causes the issue (and no its not just capitalism -- As systems become more complex with more teams and interplay among them and as peoples role increase from a pure do as you are told developer to someone who must also be make decisions/design, , multi-tasking is inevitable -- but unlike what the study says most software engineers I know will agree with that multitasking is hard and makes matters worse and they’d love to return to when they could just focus on their tasks (but at their current salary)

    Growing up in the noisiest part of Bombay, filtering noise while studying /working comes easily though.

  6. anthrosciguy says

    One of the biggest delusions we hear from students is, “I do five things at once because I don’t have time to do them one at a time.” And that turns out to be false. That is to say, they would actually be quicker if they did one thing, then the next thing, then the next. It may not be as fun, but they’d be more efficient.

    A guy I knew who was involved in racing would often use a phrase common in racing prep: “There’s never time to do it right, but there’s always time to do it over.”

  7. says

    I doubt it’s as much about “multitasking” as how divided your attention can be while doing multiple things. I suspect the types of activities matter, are they similar or disparate?

    Managing four pans on a stove, even if they take different cooking times? Likely not a problem, especially with timers or years of experience cooking.

    Letting one pan cook on the stove while you do homework? Order a pizza after it burns.


    Most multitasking experiments I have studied do not distinguish between true multitasking and doing a task with robust monitor and interrupt programs running for other tasks. That’s what I do when watching kids and doing anything else. I’ve played a lot of simple video games (minesweeper, etc) to explore what I could and couldn’t do simultaneously -- my results are consistent with the question of what parts of the brain are engaged, so two things can happen unless they need the same program simultaneously. Fun stuff, great time waster.

  9. says

    What we need is to agree on what we mean by multi-tasking. I am reminded of two things. First, from my EE/programming background, and going back 40 years, I recall the reality of a single processing unit handling multiple tasks. If there is a lot of idle time, it works well. If not, it sucks due to the context switching overhead. I remember a student programming lab that had a single PDP-11 serving a few dozen terminals. On heavy use, you could watch it “go around the room” as it switched from job to job to job. By analogy, people only have a single “processing core”, so unless the individual tasks are small and short-lived, and there’s sufficient idle time, multi-tasking will always be worse than single-task sequential work. I don’t consider “watching the kids while doing laundry” to be real multi-tasking because much of that does not require active attention (does anyone stare at the washing machine while it’s running?).

    Co-ordination and dexterity are a bit different and I don’t consider them to be in the same boat either. I’ve played the drums for over fifty years. I’ve trained myself to do things that non-drummers can’t, and sometimes that dexterity spills over into adjacent areas (for example, I have no problem patting myself on the head with one hand while making circles over my stomach with the other, while also jumping up and down on one leg while holding a conversation- something I did on a challenge from a work colleague, which literally made him laugh out loud). You know that “Spock fingers V” thing? I can do that and switch to its inverse (two center finger together, forming two Vs) repeatedly, while simultaneously doing the opposite format with the other hand. It’s a fun trick at parties. But that’s all it is. It’s just neural programming for firing muscles. Musicians do all kinds of weird things, way beyond those stupid tricks. For example, a hemiola between the left and right hands would not be odd for a pianists (that is, one hand working in duple time while the other is in triple time). As a drummer, I do that between any two limbs. The really amazing drummers (I’d suggest watching Vinnie Colaiuta or Gavin Harrison) seem to have four brains: one for each limb.

    One thing I enjoy doing is having a non-drummer sit down at my kit. If you know what to look for, you can literally see the effect of the nerve impulses not firing in proper sequence as they try to play the most basic patterns. But with practice, that will smooth out, and I don’t think it has anything to do with what we call “multi-tasking”. And by that, I mean that I cannot compose a piece of music while simultaneously correcting homework. Mind you, I can correct homework while doing paradiddles with my feet, but that’s not really multi-tasking to me.

  10. johnson catman says

    re jimf @9:

    does anyone stare at the washing machine while it’s running?

    LOL!! Your question reminded me of a song by The Pretenders, Watching The Clothes.

  11. Holms says

    Mano, I am reminded of an old post of yours on the topic of insomniacs. If I remember rightly, one finding mentioned in the sources was that those who believe themselves completely unable to sleep often do sleep shallowly, without noticing a break in their awareness thanks to their fatigue. I suspect something similar is at play here -- the people just don’t notice scattered and distracted their thinking is, perhaps specifically because their thinking is scattered and distracted.

    Also, did you grow up in a quiet rural setting? It’s possible that your inability to concentrate with background noise is because you had a quiet childhood, coupled perhaps with a preference for living in quiet areas since then. I noticed that when I lived in a very loud area -- right next to a very busy road -- my ability to tune out the noise of traffic grew over time.

    I largely agree with #3 Marcus and #9 jimf. A lot of the things cited as examples of multitasking are really examples of muscle memory letting some tasks run without conscious attention. Anyone experienced with some sort of hands-on task will have examples of physical tasks disappearing from their radar as they get better at it. The ones we can probably never multitask are the ones that don’t involve repetitive muscle action and so cannot be offloaded to the unconscious motor control portion of the brain.

    The only way I can concentrate on a task with music playing is if the music is bland. Too bad or too good, and it snags my attention.

  12. EigenSprocketUK says

    I enjoy and get quite absorbed in driving, though talking to a passenger is easy for me, even though I am likely to stop talking or paying attention with no notice.
    But… if that conversation involves recall of a place or of a sequence of events, then I’m sunk: I simply can’t do it. And if you demand it, I will have to stop the car. It’s weird, but also fascinating.

  13. Mano Singham says

    Holms @#11,

    I have lived in quiet places as well as next to a busy road with noisy buses and other traffic. It is not the ambient noise that bothers me so much because I can tune it out once my brain registers that it has nothing to do with me. But I cannot ignore anything that suggests that it might require my attention, such as people speaking.

  14. Deepak Shetty says

    @WMDKitty @14
    The contention is whether we can do it well though -- Anecdotally atleast with pre-teen kids multi-tasking is terrible (e.g. pandemic+ remote work + remote school + very limited outdoors => didnt work out too well for the multi-tasking aspect)

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