Media multitasking is increasingly part of work as well as leisure time
The people who engage in media "multitasking" are those least able to do so well, according to researchers.
A survey defined two groups: those who routinely consumed multiple media such as internet, television and mobile phones, and those who did not.
In a series of three classic psychology tests for attention and memory, the "low multitaskers" consistently outdid their highly multitasking counterparts.
The results are reported in Proceedings of the National Academy of Sciences.
"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.
"On the computer you could be emailing while you have three chats going on while you're playing World of Warcraft. If you look at classical psychology textbooks, people cannot multitask - but if you walk around on the street, you see lots of people multitasking," he told BBC News.
"So we asked ourselves the question, 'what is it that these multitaskers are good at that enable them to do this?'"
The three experiments undertaken by high and low multitaskers were designed to test three aspects that the study's authors believed must contribute to multitaskers' skills.
In the first, they were tested for their ability to ignore irrelevant information. They were briefly shown a screen with two red rectangles and either 0, 2, 4 or 6 blue rectangles.
The task was to determine whether, when the screen was shown again, one of the red rectangles had been rotated.
Low multitaskers were better at the task, regardless of the number of blue rectangles, whereas high multitaskers got worse at it as the number of distracting blue rectangles went up.
In a test of the degree of organisation of working memory, participants were presented with a series of letters, one at a time, and told to push a button when they saw a letter that they had seen exactly three letters previously.
Again, low multitaskers were significantly better at correctly spotting the repeated letters. Not only did the high multitaskers do worse from the beginning, they got worse at it as time went on.
Thirdly came a test of the participants' ability to switch tasks. They were first shown either "letter" or "number" on a screen, and then presented with a letter/number pair such as A7.
If the preceding screen said "letter", they were to determine if it was a consonant or a vowel. If it said "number", they were to determine if it was even or odd.
After, for example, a series of "number" tasks, the experimenters switched to "letter" tasks. Again, low multitaskers significantly outperformed their counterparts in switching to the new task.
The participants were put into full multitasking mode
"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."
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 team is actively pursuing new research avenues, such as studying the brain activity of the different groups as they go about their multitasking.
The results could be profound, Professor Nass said, potentially suggesting new means of teaching and even reporting news for those given to a multi-media feed of information.
But at the very least, he said, multitaskers should be told that they are bad at multitasking.
In my experience, those who claim to be able to 'multitask' are simply able to do three things badly at the same time! I can't imagine anyone ever wrote a best-seller or painted a masterpiece while simultaneously chatting on the phone and watching TV.
Justin, Bristol, UK
Since taking on a pivotal role within my current company, I am constantly interrupted by people, phones, chat, and messages. My natural attention span has decreased significantly so that even completing an email is usually interrupted by checking other emails, internet news sites and/or listening in to a nearby conversation.
Rick, Melbourne, Australia
Another potential conclusion from this research is that the tests they chose did not successfully measure the ability of participants to multitask.
Darren, Guildford, UK
Women make better multitaskers then most men, only because their lives depend on multitasking at home and at work...it seems the above study was just computer based, which is probably why the multitaskers didn't do so well...they were thinking of other things that they should've or could've been doing.
Wendy, New Glasgow, Canada
Surely the 'multitaskers' (myself included at times) are just people who tend to not focus their attention on one thing for very long, and are easily distracted by something new. The test seems to be checking how well people can ignore distractions to answer a question correctly, so from that I wouldn't consider these results unexpected at all. Any time I've been 'multitasking' I tend to perform slightly less well at each of the tasks I switch between, whether it's slight misspellings in an email, or something similar. I always try to focus on one thing at a time when it's very important.
Chris Bevan, London, UK
From a personal perspective, I like many other people tend to find that I am most stressed when I have many different things that all need to be done, and end up stressing about task B when I should be concentrating on task A. The best thing I have found is to calm down and relax, make a list and then complete the tasks one at a time until they are completed, whilst ignoring the other tasks until the time comes to complete them. Multitasking just stresses me out and reduces my performance. Human beings are not like computers.
Tom Michael, Birmingham, UK
This is surprising. I'm fantastic at it. Perhaps the pool didn't actually include those who are actually gifted enough to multitask.
Rem, London, UK
I don't see how this tests for multitasking ability at all. They are testing for attention, and attention span, which are two things I'd guess multitaskers show a lack of. They are constantly switching their focus thus having a test that requires focus on a single task / item, won't test for multi-tasking ability.
Andres, New York, USA
I am a multitasker. I have a conference call on mute as I type this. The advantage? Ignoring the detail allows me to focus on the big picture, ensuring my team are always realigning with the strategic objectives. I have a very competent group of focussed people. They're great with detailed tasks that require focus. They wouldn't let me near those activities as we all know I'd make mistakes. As a team we understand each other's strengths and weaknesses and it works well.
Sam, Manchester, UK