Multitasking is Bad for Productivity

Is multitasking bad?

Given what most people mean by multi-tasking — that is, doing two or more tasks simultaneously, the short answer is, yes it is bad.

There are people who think they are productive multitaskers.  They are, the science is beginning to show more and more clearly, fooling themselves.

There are exceptions. You can combine two low-attention or low-cognition tasks — ironing or folding laundry while chatting or watching a soap opera. I listen to books on tape while filing — because my filing is always of items pre-labeled with where they go, and it takes no thought.

These exceptions are for tasks you do so automatically you don’t need to think — like driving in light traffic, or “skimming” an information stream, like monitoring a TV to see if your show has come on yet. As soon as this low-thinking task becomes interesting, you stop multitasking.

If you try to multitask two tasks that BOTH require thought, then forget it — you are doomed.  And most people who claim they multitask are really switching rapidly between tasks.  That’s bad too.

The brain can take up to 15 minutes to “spin up” or warm up to a particular kind of activity. Switching activities — or more importantly, activity types — incurs a penalty as you mentally “change gears” to take on the new task.

Dave Crenshaw quotes a study by Basics Research (in New York) that says we lose 28% of our work days due to interruptions and the recovery time from interruptions.

The more frequently you switch, the more often you incur the penalty, and the more total time you spend “warming up” — time when you are less productive.

One of the keys of high productivity is to block out time for a task type and stick with that task type for a while. I suggest at least one hour. That could be phone calls for an hour, or email for an hour, or research for an hour.

One of the reasons we feel productive when rapidly switching is, we notice the sensation of switching task types, and we mistake it for a sensation of making progress.

In summary:
Most people who multitask are actually less productive — yet they think they are more productive.

You can avoid these negative impacts, particularly by handling interruptions in a non-intrusive way — I capture the incoming interruption using ink or a computer note, NOT my mind, and I stay on the current task type.

“The weakest ink is stronger than the strongest memory.”

Use a system to remember things, and use your brain for pattern recognition.

Crenshaw claims (I believe this is absolutely true) that switching tasks frequently results in three things:

  1. You take extra time
  2. You make more mistakes
  3. You experience increased stress

The answer is to stop it.  Or better, create systems for yourself that handle and head off interruptions, and get more disciplined around staying within a single task type for a good block of time.  (Crenshaw has an entire practice built around teaching these systems.)

Resources and links:
Media multitasking doesn’t work say researchers

NYTimes on How to Multitask
Zen Habits on How Not to Multitask
Human Task Switches Considered Harmful

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