This article is an excerpt from the Shortform book guide to "The One Thing" by Gary Keller. Shortform has the world's best summaries and analyses of books you should be reading.
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In a world of endless to-do lists, the multitasking myth suggests that juggling tasks boosts efficiency. In reality, this habit is actually “task-switching,” which forces the brain to constantly reorient, leading to more mistakes and a drop in productivity.
To achieve high-quality results, we must move past the distraction of doing everything at once. Read more to explore why sequential focus is the true key to success and how debunking the myth of multitasking can reclaim your time and reduce stress.
Originally Published: August 9, 2021
Last Updated: January 4, 2026
The Multitasking Myth
In The ONE Thing, Gary Keller discusses the multitasking myth—the belief that you can get more done by multitasking. The truth is that you can’t. Multitasking actually stands in the way of success.
With impossibly long to-do lists, many people believe multitasking is something they should learn and practice in the name of efficiency. Web pages and blogs offer multitasking instructions. Some employers list multitasking as an essential skill for prospective hires.
However, 2009 research by Clifford Nass of Stanford University showed it doesn’t work. While multitaskers think they’re succeeding, they’re actually performing poorly. Nass found that multitaskers “were lousy at everything.” As speaker and author Steve Uzzell noted, “Multitasking is merely the opportunity to screw up more than one thing at a time.”
Keller explains that what we call “multitasking” is actually just task-switching, and it comes with significant costs. Research shows that switching tasks can reduce productivity because, with each switch, your brain needs time to refocus.
Rather than juggling their attention across multiple priorities, the most productive people work sequentially, doing one focused task at a time. This leads to higher-quality results in less time, writes Keller.
(Shortform note: Research supports Keller’s claim that people commonly think that multitasking is effective. In one 2018 study, researchers found that 93% of people think they can multitask as well as or better than the average person. Despite this—and despite it being statistically impossible—others have found that only about 2.5% of people can actually multitask effectively and that those who multitask most frequently are often the least capable at it. Meanwhile, people who score high on multitasking ability tests tend not to multitask in real life, but rather to focus on single tasks.)
Origins of Multitasking
Multitasking might be a holdover from humans’ earliest days, when they had to watch their surroundings for predators while doing other things like picking berries. We seem to be wired to try to do more than one thing at a time. Because we feel so pressed for time, multitasking has become a hallmark of the modern human.
The term multitasking entered the lexicon in the 1960s, when scientists used it to describe computers’ ability to do many things quickly. However, it was a misnomer: rather than doing multiple things simultaneously, computers alternate tasks requiring memory until the tasks are done. Their speed makes it seem like they’re doing things simultaneously.
People actually can do two things at once—for instance, walk and talk. But like computers, we alternate our focus. Or we process different types of information in different parts of the brain. When we’re engaged in two activities, the brain controls one in the background and the other in the foreground.
A conflict occurs when an activity requires a brain channel already in use or when one task demands greater attention—for example:
- If you’re walking across a gorge on a rope bridge, you’ll have to stop talking and pay attention to your hands and feet.
- When you’re “absentmindedly” petting your dog while watching a football game on TV, your dog knows he’s not getting your full attention and nudges you.
- If you’re driving while your spouse is talking to you about rearranging the living room furniture, you’ll focus on a mental picture of the living room instead of seeing the car braking in front of you.
Disadvantages of Multitasking
Because of the persistence of the myth, today’s workplaces are a multitasking circus. This costs time and productivity.
For instance, when a coworker interrupts you with a question while you’re working on a spreadsheet, you have to switch your attention to the new task and then later restart the one you suspended. This takes time—researchers estimate that employees are interrupted every eleven minutes and spend a third of their day recovering from interruptions. It also takes longer to do things. Depending on the complexity of the task, switching can add 25% to 100% more time to completing it.
Besides external interruptions, there are other distractions. Computer users change windows or check email or other programs 37 times an hour. You actually get a jolt of dopamine when you switch, making attention-shifting addictive.
To sum up the disadvantages of multitasking:
- When you divide your limited brain capacity, you decrease your effectiveness.
- The more time you spend on a task you switched to, the less likely you are to resume your original task.
- When you bounce between activities, you lose time as your brain reorients.
- Multitasking skews your sense of how long it takes to do things and you overestimate the time required.
- When you multitask, you make more mistakes and make bad decisions because you favor new information over old, whether it’s relevant or not.
- Multitasking creates stress. While we think we’re multitasking, we’re driving ourselves crazy.
Multitasking doesn’t save time; it wastes time.
The Cost of the Multitasking Myth
Society is beginning to understand and take seriously the risks of distraction in one area: driving a motor vehicle. Distracted driving causes 16% of fatalities and a half-million injuries a year. Talking on the phone while driving can take 40% of your focus and can have the same effect as driving drunk.
As a result of the increased awareness, many states and communities have banned using the phone while driving. We should take distraction just as seriously at work and in our home life.
If you lose a third of your workday to distractions, imagine what it costs you and your business over the course of a career. Distractions erode your personal relationships each time you ignore the needs of your spouse, children, or friends to check your cell phone.
All of this is a steep price to pay for something—multitasking—that doesn’t work to begin with.
You won’t succeed in your work or life unless you throw out the myth of multitasking and figure out what matters most in the moment and give it your undivided attention.
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- Why focusing daily on one thing, rather than many, is the key to success
- How success is like dominos
- The six common myths about success
