The researchers studied 262 college undergraduates, dividing them into high and low multitasking groups and comparing such things as memory, ability to switch from one task to another, and being able to focus on a task. Their findings are reported in today’s edition of Proceedings of the National Academy of Sciences.
When it came to such essential abilities, people who did a lot of multitasking didn’t score as well as others, Nass said.
Still to be answered is why the folks who are worst at multitasking are the ones doing it the most.
It’s sort of a chicken-or-egg question.
“Is multitasking causing them to be lousy at multitasking, or is their lousiness at multitasking causing them to be multitaskers?’’ Nass wondered. “Is it born or learned?’’
In a society that seems to encourage more and more multitasking, the findings have social implications, Nass observed.
Multitasking is already blamed for car crashes as several states restrict drivers’ use of cellphones. Lawyers or advertisers can try to use irrelevant information to distract and refocus people in a bid to influence their decisions.
In the study, the researchers first had to figure out who are the heavy and light multitaskers. They gave the students a form listing a variety of media such as print, television, computer-based video, music, computer games, telephone voice or text, and so forth.
The students were asked, for each form of media, which other forms they used at the same time always, often, sometimes, or never.
The result ranged from an average of about 1.5 media items at the low end to more than four among heavy multitaskers.
Researchers then tested the abilities of students in the various groups.
For example, ability to ignore irrelevant information was tested by showing a group of red and blue rectangles, blanking them out, and then showing them again and asking if any of the red ones had moved.
The test required ignoring the blue rectangles. The researchers thought people who do a lot of multitasking would be better at it.
“But they’re not. They’re worse. They’re much worse,’’ said Nass.
The high media multitaskers couldn’t ignore the blue rectangles.
“They couldn’t ignore stuff that doesn’t matter. They love stuff that doesn’t matter,’’ he said.