When you feel overwhelmed with how much you have to do your brain panics. It is obvious to your brain that doing one thing at a time isn’t going to get it all done, so it makes what it believes to be a brilliant suggestion … “Let’s do more than one thing at a time!”

You Cannot Think Two Thoughts At Once

The slight problem with your brain’s choice is that although you can multi-task some things (walk, breathe and eat an apple), you cannot think two thoughts at the same time. So your brain does the next best thing and switches between the tasks as rapidly as it can.

Switch Tasking Wastes Energy

Switch tasking is a hungry monster that chews up energy changing tasks, turning rules on and off for each task and trying to remember where you were up to each time you switch. Each switch loses you one to two seconds (more if you are older, addicted to multitasking or the task is complex) and release stress hormones. While you feel you are getting more done, it is like spinning wheels in a car that only has first gear. You look busy, but there is not much forward direction.

Multi-tasking Gives You Blind Spots

Multi-tasking leads to ‘blind spots’ because you cannot focus on two things at once. If you are writing an email while talking on the phone, you will miss chunks of the conversation or make grammar mistakes in your email. If you are sending a text during a meeting, you will miss chunks of the meeting while you send the text. These blind spots are when expensive and embarrassing errors happen.

Researchers Could Not Find Any Benefits Of Multitasking

Given how common multitasking is, researchers from Stanford Uni went looking for its benefits but couldn’t find any. What they found instead is:

  • If you try to multi-task two tasks at the same time, it will take you 50% longer than if you did them one after the other.
  • You will make twice as many errors.
  • That multitasking is unproductive, stressful and addictive.
  • Multitasking is causing people to be easily distracted and to be worse at clear thinking, being organised, analytic reasoning and creative thinking.

The Surprisingly Simple Answer

The most effective way to get more thinking tasks done is to focus on one at a time. You will get your work done in less time, enjoy it more and conserve energy you otherwise would have wasted switch tasking.

Notes: Research comes from (1) Klaus Manhart, “The Limits of Multitasking,” Scientific American Mind, December 2004, (2) Joshua S. Rubinstein, David E. Meyer and Jeffrey E. Evans, “Executive Control of Cognitive Processes In Task Switching,” Journal of Experimental Psychology: Human Perception and Performance, 2001, Vol 27, No 4, pp 763 – 797, (3) Joshua Rubinstein, E0mail Exchange, September 26, 2006, (4) Eyal Ophir, Clifford Nass and Anthony D. Wagner, “Cognitive Control In Media Multitaskers,” PNAS, 2009, Vol 106, Number 37, p 15583-87, (5) ‘Multi-Tasking Adversely Affects The Brain’s Learning Systems’ Russell Poldrack, A Psychology Professor at the University of California, Los Angeles.