Time is what prevents everything from happening at once.
— John A.Wheeler
I have always been a little skeptical of the claim, made by some people, that they are able to “multi-task”: to carry on, and keep track of, more than one activity simultaneously. It seems that many people believe this is possible, judging from the number of people one sees talking on their cellphones while walking down the street or driving, or trying to carry on a conversation while listening to a music player. Yet standard textbooks on the psychology of cognition usually say that processing more than one stream of information at a time is not possible. So I was amused to read a report at the BBC News about a study done at Stanford (paper published in the Proceedings of the National Academy of Sciences [abstract]), which attempted to determine what enabled some people to multi-task effectively.
“Increasingly, people who are looking at their computer screen are frequently watching TV, listening to the radio, maybe reading print media, chatting, texting,” said Cliff Nass, a co-author on the study from Stanford University.
It turns out that the short answer is “nothing”; that is, it seems that people who think they can multi-task are deluding themselves. The researchers first divided their experimental subjects into two groups: those that frequently multi-tasked, and those that didn’t; they then used standard cognitive tests to look at the performance of the subjects in three areas:
- Ability to ignore irrelevant information
- Organization of working memory
- Ability to switch between tasks
The results were consistent with common sense and with the textbooks. The people who habitually multi-tasked performed worse on all the tests of cognition than those who usually try to do only one thing at a time. It’s particularly striking that, even in the last test, which looked at the subjects’ ability to switch to a new task, the multi-taskers did worse. To put it another way, the people that normally multi-tasked the most were the least able to do it.
What seems to be going on here is that the multi-taskers cannot stay adequately focused on any single task, even for a very short time.
“The shocking discovery of this research is that [high multitaskers] are lousy at everything that’s necessary for multitasking,” Professor Nass said.
“The irony here is that when you ask the low multitaskers, they all think they’re much worse at multitasking and the high multitaskers think they’re gifted at it.”
It’s not clear, however, whether people are drawn to multi-tasking because of their inability to pay attention, or if the practice of multi-tasking makes them unable to concentrate.
The pressing question that remains, Professor Nass said, is one of cause and effect: are those people with a dearth of multitasking skills drawn to multitasking lifestyles, or do the lifestyles dull the skills?
The Stanford University News Service also has an article on this research.
These are interesting results; if nothing else, they should give people who argue that it is perfectly safe to drive a car and talk on the phone at the same time something to think about — if they can stay focused long enough.