A recent article published in the Proceedings of the National Academy of Sciences (PNAS) by three Stanford University researchers offers perhaps the most surprising result: those who consider themselves to be great multitaskers are in fact the worst multitaskers. Those who rated themselves as chronic multitaskers made more mistakes, could remember fewer items, and took longer to complete a variety of focusing tasks analogous to multitasking than those self-rated as infrequent multitaskers. In a recent interview with NPR, a co-author of the PNAS study, Clifford Nass, states, "The shocking discovery of this research is that [high multitaskers] are lousy at everything that's necessary for multitasking." Nass concluded that this difference appears to be due to an inability to filter past and no-longer-relevant information from the previous task.
A Grain of Salt
Despite the apparent persuasiveness of this research, I would approach Nass's findings with a grain of salt. My concerns relate to what is called the "external validity" of research, in layperson's terms, "the degree to which the conclusions in your study would hold for other persons in other places and at other times." Like most university research, Nass's studies used college undergraduates as experimental subjects. We might ask how representative college students are of the general population (and especially the population of technologists). Also, the tasks that they engaged in were not real-life activities but rather analog tasks that purport to test the same attributes as multitasking. Again, we might ask whether those contrived tasks are predictive of behavior in the real world. Even Nass notes in that PNAS article that, "It remains possible that future tests of higher-order cognition will uncover benefits...of heavy media multitasking..."
I should note that other research described in a Wired article involving normal activities has reported, for example, that children perform worse on their homework if it is done while watching TV and employees show greater productivity when they don't check their email frequently. So there is considerable evidence against multitasking outside of the laboratory as well.
My consulting work with leading technologists, businesspeople, athletes, and coaches offers further support to my belief that multitasking is just not the way to go. The goals of these top performers with whom I work are not just to be productive and efficient, but rather to be the very best in their fields and to push the envelope of what is possible. Even a 1% improvement in their performance or productivity can mean dramatic differences in output. And I have found that single tasking, meaning focusing only on those tasks that are absolutely essential to maximize performance, is an effective tool for making small, yet profound gains in productivity.
Though questions still exist and there is still a need for further study, the preponderance of evidence does suggest that multitasking isn't all it's cracked up to be. With all things considered, I believe there is enough evidence to support the notion that other approaches to task completion can be more effective and efficient than multitasking.
Where to Now
Have I convinced you that it's time to stop (or at least reduce) your multitasking habits? If so, I'll devote my next post to offering you practical steps you can take to "single task" in order to become more productive and efficient.
This story, "Multitasking Is a Big Fat Lie" was originally published by Computerworld.