Can multitasking decrease efficiency

Our brains are not designed to multitask

Our brains are not designed to do several different things at the same time. Trying to do multiple tasks at the same time slows it down and can potentially even lead to permanent damaging changes in the brain.
Earl Miller, a neuroscientist at the Massachussets Institute of Technology, notes that our brains “are not well equipped to multitask ... When people think they are doing multiple tasks at the same time, they are actually switching between tasks very quickly. With every change, cognitive losses arise. "(Link)
If multitasking is scrutinized more closely in psychological research, it quickly becomes clear that real multitasking, as the simultaneous completion of tasks, cannot be achieved by humans. Rather, the various tasks are divided into individual subtasks and processed in a constantly changing sequence. In addition to many other factors, this requires a constant change of attention and the maintenance of memory contents. Psychological studies show that it is not possible in principle to divide attention between different activities at one point in time!
Constantly switching between several tasks can also lead to bad habits. This is reinforced by the way our brain works: even the smallest task, such as sending an email or replying to a WhatsApp message, leads to the release of the extremely powerful reward hormone Dopamine. But our need for social contact, which is strongly regulated in the brain by the hormone oxytocin and also associated with pleasant feelings, is apparently satisfied by digital networking.
Since our brain reacts particularly positively to this, we try everything to repeat this "kick" as often as possible by constantly switching between many small tasks that promise an immediate reward. We also deliberately turn to unimportant information that only slows us down (Prof. C. Nass: "suckers for irrelevancy"; Link). Research shows that up to a third of working time is spent on querying and reading messages.
This can lead to a problematic vicious circle: we get the feeling that we are completing thousands of tasks, while in fact we hardly solve any tasks with greater demands and get lost in the little things. In this way, even reading Facebook or Twitter messages can lead to a kind of neural dependency and burden us with secondary tasks and ultimately isolate us socially.

Multitasking reduces quality and efficiency

Multitasking makes it much harder to organize your thoughts and filter out unimportant information. As a result, tasks are solved much more inefficiently and the quality also suffers.
A study at the University of London showed that multitasking when solving cognitive tasks leads to a drop in IQ that is roughly comparable to the level after a sleepless night or after consuming marijuana.
Multitasking also increases the production of the stress hormone cortisol. Not only does this make us feel stressed and driven, it can also make us feel tired and mentally burned out before the work day starts.
But even if we don't actually do multitasking, but only have the opportunity to do so, it can significantly degrade our performance. Various studies have shown that just knowing about an unread e-mail worsens our IQ by 10 points.
The active e-mail program or notification symbols on the screen create a feeling of constant inner pressure in us, while we also keep the awareness of the unfinished business in the back of our minds constantly awake. Our mental and physical alarm system is practically uninterrupted in the beware position - that is just tiring in the individual situation and robs us of our nerves. Over long periods of time, this can contribute to chronic stress.
Due to the speed and high immediacy, reading and writing messages in social networks should top this effect by making much more intensive use of our intellectual resources.

Possible permanent damage

Recent research suggests that multitasking can potentially lead to permanent changes in the brain. In a study by the University of Sussex, it was possible to show with the help of imaging methods that people who often perform several tasks at the same time have a lower density of nerve cells in certain places in the brain (in the anterior cingulate cortex). These areas are involved in experiencing compassion and emotional control.
However, it is not clear from the study whether multitasking actually leads to these changes, or whether these changes tend to encourage people to tackle several tasks at the same time.

The myth of multitasking

In any case, the ability to multitask, regardless of whether it is women or men, is a myth that has no evidence in scientific research. At most, highly automated activities with low mental requirements can be carried out on the side. Next time you ask your significant other how much milk is left in the refrigerator while she / he is tying shoelaces - and watch carefully.


Understand the inefficiency of multitasking

I had fun and tried the experiment proposed by t3n to illustrate the lower productivity in multitasking (Link). Certainly it does not meet any scientific standards either theoretically or methodically - but it is an example that does not work without a reason.



The task is to enter the numbers from 1 to 23, the letters A-W and the Roman numerals I-XXIII in three columns. In the "single tasking" condition, which should correspond to the complete processing of tasks, the columns are described one after the other ("1 → 2 → 3 ...", "A → B → C ...", "I → II → III ... ").
In the condition, which is intended to indicate the difference in "multi-tasking", an entry is made per line so that one always enters number, letter and Latin number one after the other and thus constantly changes between the different modes ("1 → A → I "," 2 → B → II "etc.)
In fact, I come up with a difference of 12 seconds in the processing time. Switching between modes caused a noticeable slowdown in even such a simple task. Now I have long forgotten how to write handwriting ... the fatigue effect of the hand during the 2nd run (“multitasking”) should be offset by a pre-activation of the symbols.
P.S .: Since I am a little vain, I did not want to leave the matter to my results alone. The results of the linguistically gifted colleague in the office next to the practice do not manage to put me in a better light, but they also confirm the lower efficiency of multitasking (1 min. 17 sec. Compared to 1 min. 23 sec.).


Ways to deal with the resource killers

  • Making calls and writing messages while driving are absolutely taboo.
  • Check for e-mails and other messages only on a specific schedule; e.g. always in the morning, at noon and in the evening
  • limit the time you spend reading, answering and browsing: e.g. to 1 to 2 hours a day.
  • Consciously take time off from such seemingly unimportant activities. Just do nothing for half an hour every day.
  • Turn off on-screen and audible notifications for email and social network messages.
  • Set the programs so that they only request new messages at certain times.
  • Remind yourself of other ways to activate your reward system: For fun, try just one task, but do it completely.
  • With their high proportion of blue light, modern screens mess up our biorhythms and promote sleep difficulties and lack of concentration. (No TV or monitor light in the evening)