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  • Steve Nguyen, PhD

Multitasking Doesn’t Work

Updated: Aug 24, 2022

[NOTE: This post was updated January 2017]

Multitasking is a word that gets thrown around a lot these days. But it’s important to understand what it is and why it doesn’t work. Multitasking is when we juggle multiple things (thoughts and actions) at the same time. For example, people multitask when they drive and talk on their cell phones (Donatelle, 2009). It may surprise you to hear, however, that people who multitask are actually less productive than those who just concentrate on one project a time.

A recent Harvard Business Review post said multitasking leads to as much as a 40% drop in productivity, increased stress, and a 10% drop in IQ (Bergman, 2010).

Perhaps no other example better illustrates why multitasking doesn’t work than distracted driving. Studies have found that driving while distracted (being on the phone or texting) is actually more dangerous than driving drunk.

Here are some eye-opening statistics:

  • Ten percent of fatal crashes, 18 percent of injury crashes, and 16 percent of all police-reported motor vehicle traffic crashes in 2014 were reported as distraction-affected crashes (NHTSA).

  • In 2014, 3,179 people were killed, and 431,000 were injured in motor vehicle crashes involving distracted drivers (Distraction.Gov).

  • Using a cell phone while driving, whether it’s hand-held or hands-free, delays a driver’s reactions as much as having a blood alcohol concentration at the legal limit of .08 percent (University of Utah).

  • Five seconds is the average time your eyes are off the road while texting. When traveling at 55mph, that’s enough time to cover the length of a football field blindfolded (Distraction.Gov).

According to Strayer, Watson, and Drews (2011) “cell-phone conversations compete for attention with driving. The result is that visual processing is substantially impaired when drivers are talking on a cell phone (either hand-held or hands-free)” (p.47).

However, not all conversations engaged in while driving are harmful. Researchers have found that in-vehicle conversations (i.e. conversations with passengers in the car) are very different from cell-phone conversations. Why? Because “the passenger often actively engaged in supporting the driver by pointing out hazards, helping to navigate, and reminding the driver of the task (i.e., exiting at the rest stop). In other cases, the conversation was temporally halted during a difficult section of driving and then resumed when driving became easier” (Strayer et al., 2011, p. 48).

Strayer et al. (2011) found those who talked on the cell phone were more likely to drift into the other lane and more likely to miss an exit. Further analyzing conversations, researchers discovered that drivers and passengers in the car tended to adjust their conversations in response to traffic cues. For instance, they both stopped talking if there was a traffic problem or the passenger would give advice to help the driver navigate. On the flip side, conversations on cell phones didn’t vary based on traffic conditions because, obviously, only the driver can see the road. “In effect, the passenger acted as another set of eyes that helped the driver control the vehicle, and this sort of activity is not afforded by cell-phone conversations” (Strayer et al., 2011, p. 48).

Ophir, Nass, and Wagner (2009) discovered that people who reported multitasking more frequently (heavy multitaskers) were actually more prone to being distracted compared to those who reported multitasking less frequently (light multitaskers). Heavy multitaskers tend to have a hard time filtering out irrelevant stimuli from their environment, and are distracted by the multiple things that they’re trying to allocate their attentions to. In essence, heavy multitaskers may be “sacrificing performance on the primary task to let in other sources of information” (Ophir, Nass, & Wagner, 2009, p. 15585).

Finally, for those who still argue that they’re great at multitasking, research indicates that even though we think we’re “multitasking” it’s actually our brain rapidly switching from one task to another, rather than processing them simultaneously. People who seem to be good at multitasking are simply good at being faster at switching back and forth between two things (Scientific American, 2009).


  • People who multitask are less productive/efficient than those who simply concentrate on one project a time.

  • We don’t actually “multitask” because your brain switches rapidly between handling one task and then another.

  • Simplify your life and your tasks. Do fewer things — better.

Written By: Steve Nguyen, Ph.D. Organizational & Leadership Development Leader


American Psychological Association – Multitasking: Switching costs

Bergman, P. (2010, May 20). How (and why) to stop multitasking. Harvard Business Review.

Distraction.Gov – What is Distracted Driving

Donatelle, R. (2009). Health: The basics (8th ed.). San Francisco: Pearson Benjamin Cummings.

National Highway Traffic Safety Administration (NHTSA). Traffic Safety Facts: Research Note. Distracted Driving 2014.

Ophir, E., Nass, C. I., & Wagner, A. D. (2009). Cognitive control in media multitaskers. Proceedings of the National Academy of Sciences, 106(37), 15583-15587. doi:10.1073/pnas.0903620106

Scientific American. (2009, July). The Myth of Multitasking.

Strayer, D. L., Watson, J. M., & Drews, F. A. (2011). Cognitive Distraction While Multitasking in the Automobile. In B. Ross (Ed.), The psychology of learning and motivation (Vol. 54, pp. 29-58). Burlington: Academic Press.

University of Utah – Cell Phone Users Drive “Blind”

University of Utah – Drivers on Cell Phones Are As Bad As Drunks

University of Utah – Frequent Multitaskers Are Bad at It



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