Multitasking myth

According to Professor Clifford Nass from Stanford University, research shows that there is no evidence that people who multitask achieve more. From Proceedings of the National Academy of Sciences of the United States of America,
August 24, 2009, doi: 10.1073/pnas.0903620106 abstract

Cognitive control in media multitaskers

1. Eyal Ophira, 2. Clifford Nass,1 and 3. Anthony D. Wagnerc

1. Symbolic Systems Program and
2. Department of Communication, 450 Serra Mall, Building 120, Stanford University, Stanford, CA 94305-2050; and
3. Department of Psychology and Neurosciences Program, Jordan Hall, Building 420, Stanford University, Stanford, CA 94305-2130

Edited by Michael I. Posner, University of Oregon, Eugene, OR, and approved July 20, 2009 (received for review April 1, 2009)

Chronic media multitasking is quickly becoming ubiquitous, although processing multiple incoming streams of information is considered a challenge for human cognition. A series of experiments addressed whether there are systematic differences in information processing styles between chronically heavy and light media multitaskers. A trait media multitasking index was developed to identify groups of heavy and light media multitaskers. These two groups were then compared along established cognitive control dimensions. Results showed that heavy media multitaskers are more susceptible to interference from irrelevant environmental stimuli and from irrelevant representations in memory. This led to the surprising result that heavy media multitaskers performed worse on a test of task-switching ability, likely due to reduced ability to filter out interference from the irrelevant task set. These results demonstrate that media multitasking, a rapidly growing societal trend, is associated with a distinct approach to fundamental information processing.

There is another simple proof that multitasking is a myth. People who use their phones for talking or texting while they are driving.

See also David Glenn's article in The Chronicle of Higher Education.

Busy people might think they are multitasking, but in reality they are merely juggling a number of tasks at the same time but undertaking one task at a time while in readiness of the next one.