Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Success

by Brad Stulberg

Even in individuals who claim to be great multitaskers, fMRI scans of the brain reveal it is impossible to do two things at once with a high level of quality. When we multitask, our brains either constantly switch between tasks or they divide and conquer, allotting only a portion of our cognitive capacity to a specific task. As a result, as countless studies show, the quality and, ironically, even the quantity of our work suffers when we are multitasking. Although the switching costs may seem trivial—sometimes just a few tenths of a second per switch—they add up over time as we switch back- and-forth between tasks. Researchers at the University of Michigan found that seemingly innocuous multitasking can cannibalize as much as 40 percent of someone’s productive time. Although it may feel like we are getting twice as much done when multitasking, we’re actually getting close to half as much done.