The Truth About Multitasking

A scientific treatise on the topic

The individual of the 21st century is the born multi-tasker. She’s used to instant massagers, podcasts and TV. She’s listening to something while making her dishes, checks her emails while working on a presentation and texts on her smartphone while watching TV. She’s in constant stress, but everything else drives her crazy. She’s convinced that she can handle multiple things at the same time. Her reflexes and perception work much quicker and better. She’s able to cope with several projects on one single day. She’s a true 21st century workaholic. Or so she thinks.

The common belief is that multitasking makes you more productive, that multi-taskers are more talented and that women are the better multi-taskers, yet science suggests otherwise. Multitasking makes you unproductive [1]. It slows you down, increases the rate of your mistakes and reduces your ability to process information [2]. Moreover, it changes the structure of your brain, resulting in decreased cognitive control performance and less socio-emotional regulation [3].

One study in particular assesses students’ perspectives on multitasking. Every student believed that they frequently multitask, that multitasking increases their productivity and that there are differences in gender. Only the first of those assumption is true [4] [5]. The study clearly demonstrated that students performed much worse if they multitasked. The book ‘The One Thing’ lists several more studies, one of them focusing on multi-taskers and single-taskers perception on productivity. Multi-taskers believe they are much more productive than single-taskers, but are indeed heavily outperformed by them. They scored worse on almost every single aspect [6].

The idea is that you can do two things at once. But you cannot focus on two things at once. Daniel Kahneman describes in his book ‘Thinking, Fast and Slow’ that there are two systems in our brain, which he calls System 1 and System 2. System 2 is slow and logical and is used when we solve a difficult math task for example. System 1, on the other hand, is quick and intuitive and is used when we walk, talk or do any other automated task. While we can do several intuitive tasks at the same time, our System 2 requires full attention [7]. Think of driving a car: Both driving and talking is an intuitive task, so you can do both at the same time. But suddenly, something unexpected happens. Your System 2 requires your full attention. In the lucky case, you stop talking and handle the situation well. In the worst case, talking occupied so much of your brain power that your System 2 wasn’t able to react quick enough. This is why multitasking fails: Knowledge Work as described by Peter Drucker, i.e. work that requires us to code, manage, organize or think in general, requires our System 2. It’s neurologically impossible to multitask!

Well, almost: It’s neurologically impossible to multitask with two System 2 tasks. That means: Never do your mails while creating a power point presentation. Never check your phone while studying. Never switch between two tasks of cognitively stimulating work simultaneously. However, you can listen to an audio book while doing the laundry. You can check your phone while walking on an empty street. You can fill in excel sheets while listening to music. That is because all of those involve at least one light-weight System 1 task.

Remember that your brain only has space for one of those tasks. If you have ever noticed that you have no idea where you put your keys because you listened to a podcast while coming home or had your thoughts somewhere else, this is because your System 2 was occupied with another task. If I tidy my room, for instance, I refrain from listening to an audio book. I did so in the past and had my room tidy eventually, but could never remember where I put the stuff I tidied up. On the other hand, if I had a system to put everything at one place exactly when tidying up, a place that would never change, I would be able to multitask while tidying up. The level of automation will determine whether you will be able to add another cognitively demanding task. The recipe is fairly simple: The moment you need conscious focus to do something, your System 2 is at work and multitasking is a bad idea.


  1. Focus: Multitasking is stupid for knowledge work. If you’re not convinced, we can recommend you to read this series of articles: 1,2,3,4. The more time you’ll dedicate to being focused a day, the fitter your brain will be, the happier you will be and the more you will get done. Focus is the key principle of every successful individual. If you haven’t made this your habit, I highly recommend you do so.
  2. Multitask smartly: In very rare cases, multitasking is indeed possible. If a task is 100% automated, try to be more productive by listening to an audio book or a podcast simultaneously. If you’re not yet doing this, I can highly recommend you do so. Doing laundry, washing dishes and commuting somewhere can take up more than 15 hours a week. This translates into 3 audio books, if you’re listening at twice the speed. You might become an expert on topics you haven’t even studied, just by adhering to this principle.

Note that this is article one in a whole series of articles. You can find the subsequent articles as well as articles regarding other topics, such as sleep and flow, on our website. After you have read our articles, not only will you have a thorough understanding of your body and your inner workings, but you will also be able to put that knowledge into use and apply it flexibly throughout your live to design your individual desired plan of winning life.


[1] Bannister, F. & Remenyi, D. (2009). Multitasking: the Uncertain Impact of Technology on Knowledge Workers and Managers. Electronic Journal Information Systems Evaluation. 12.

[2] Lohr, S. (2007) Slow Down, Brave Multitasker, and Don’t Read This in Traffic,The New York Times, March 25th, 2007,

[3] Loh KK, Kanai R (2014) Higher Media Multi-Tasking Activity Is Associated with Smaller Gray-Matter Density in the Anterior Cingulate Cortex. PLoS ONE 9(9): e106698. doi:10.1371/journal.pone.0106698

[4] Jones, Keith and Schambach, Thomas, “Student Perspectives On Multitasking” (2009). 2009 Proceedings. 23.

[5] Laloyaux, J., Laroi, F., & Hirnstein, M. (2018, September 26). Research: Women and Men Are Equally Bad at Multitasking. Harvard Business Review. Retrieved from

[6] Gary, K. & Papasan, J. (2013). The ONE Thing: The Surprisingly Simple Truth Behind Extraordinary Results. Austin: Bard Press.

[7] Kahneman, D. (2011). Thinking, fast and slow. New York: Farrar, Straus and Giroux.