Why You Can’t Multi-Task
And when you can.
Posted November 15, 2018 | Reviewed by Jessica Schrader
You probably know a person or two that brags about how good of a multi-tasker they are. Especially in today’s “hustle and grind” work culture, you’ll see them typing away on their phone while walking, driving, sitting in a meeting, or even making a phone call. Because of this braggadocio, you may even still feel the temptation to squeeze out just a little bit more productivity by trying to pair two items from your to-do list or calendar together.
You can’t multi-task. Not really. And neither can anyone else.
We know from several really well-conducted studies into human psychology and brain science that we don’t actually multi-task. Not in the sense that we’re doing two activities at the same time with sufficient focus. Instead, the human brain “task switches” constantly between the two different demands vying for its attention. And it doesn’t switch all that well.
Think of task switching as less like multi-tasking and more like juggling. You have a couple different balls in the air, but you're only really touching one at a time. You’re catching and releasing quickly and hopefully paying just enough attention to the other balls that as they’re coming down you can swoop in and catch a new one just after releasing the prior.
In fact, juggling works really well as an analogy because there’s really only two outcomes when you attempt to juggle tasks: you either drop one or do both slowly.
The transition between activities in task switching isn’t seamless. It costs the brain a few moments of time to adjust every time you switch. By some estimates, when you attempt to multi-task you actually end up taking 40 percent longer to finish then you would be giving one task your complete attention at a time.
That or you end up dropping the ball. Sometimes dropping the ball looks like missing some contextual clue, having too many typos, or not retaining everything that was shared in a meeting. But other times dropping the ball can be more costly, like the potential costs of texting while driving.
The juggling—and ball dropping—analogy also gives us a clue as to when we can get away with multi-task-switching. If you’re comfortable dropping one of the balls, then go for it. But make sure you’ll drop the right one. In other words, make sure you pair cognitively demanding tasks with ones that aren’t cognitively demanding or at least aren’t that costly. Listening to an audiobook while working out, or working through your email box, are good examples. Yes, retention might suffer, but so long as it’s not vital you retain every idea in the book, it’s okay.
You cannot multi-task. No one can. You can only task switch. You can only juggle. So if you’re going to give in to the multi-task temptation, just make sure you know which ball to drop.