Multitasking May Not Mean Higher Productivity

A new study says so-called "heavy multitaskers" have trouble tuning out distractions and switching tasks compared with those who multitask less. And there's evidence that multitasking may weaken cognitive ability. Stanford University professor Clifford Nass explains the work.



From NPR News, this is SCIENCE FRIDAY, and I'm Paul Raeburn. Up next, a look at what seems to be an increasingly normal state for most of us: multitasking -the dreaded multitasking.

Stop for a second and think about all the things you're trying to do right now: listening to the radio - I hope you're listening. Maybe you are driving, texting. I hope you're not texting while you're driving. You could be talking on a cell phone, another bad idea when you're driving. If you're at home, we'd like to think you're giving us your complete and full attention, but we know better. You might be checking email or scanning a magazine or trying to read the directions on a microwaveable burrito. I don't know what you're doing, but I'm sure you're doing several things at the same time.

If you've got all those things going on, you are what my next guest would call a heavy multitasker. And most heavy multitaskers think they are pretty good at it. Well, wrong.

My next guest has studied the habits of multitaskers, both light and heavy, and he has found that doing more often means doing less. Joining me to talk more about it is my guest. Clifford Nass is the Thomas M. Storke Professor at Stanford University. He joins us from a studio at Stanford. Thanks for talking with us, Dr. Nass.

We have - we'll try to get Dr. Nass back.

Dr. CLIFFORD NASS (Thomas M. Storke Professor, Stanford University): Any luck?

RAEBURN: The phone number is 1-800-989-8255. Give us a call, and I think we have Dr. Nass back. Welcome to the program.

Dr. NASS: Thank you very much, glad to be here.

RAEBURN: So how do we define a multitasker? I don't know. We all know what a multitasker is in our own terms, but how do we define that a little more scientifically? How do you do it?

Dr. NASS: Well, we're talking about media multitaskers. So we're talking about people who are receiving and, you know, using multiple streams of information at once that are unrelated. So people, for example, chatting with a number of different people while working on a paper, while reading something, while listening to TV, while looking at the newspaper, etc.

RAEBURN: OK, and you have a way of sort of measuring that or defining it? Do you count the seconds somebody does something?

Dr. NASS: We're actually interested in chronic multitaskers. So what we do is we present people initially with a questionnaire that asks about different categories of media and says: How often, when you're doing this category of media, are you also using this category, also asking the amount of time. And then through various statistics, we're able to put together a profile of people who are either very, very frequently using many, many media and those who are eschewing media and using, at most, one or two at a time.

RAEBURN: And now, many of us in my business think of ourselves as great multitaskers, and we feel like we have to do it to get our work done - in many other businesses, too. And we think we're pretty good at it, a lot of us. What's going on here? This is frightening news.

(Soundbite of laughter)

Dr. NASS: Well, it is frightening. It was frightening to the researchers, too. One of the things that seems to be true is people who multitask very, very frequently believe they are excellent at it, and they're actually, as far as we can tell, the worst at it of any people.

RAEBURN: The people who think they're the best are the worst.

Dr. NASS: Correct, correct.

RAEBURN: What's going on? How can that be?

Dr. NASS: Well, we don't actually fully understand it. One possibility is that people who multitask frequently just like doing it. They like what is called exploring rather than exploiting. And because they're doing it all the time, they feel that they're good at it because it's hard to justify doing it all the time if they're not. That's one possibility.

Another possibility is there may be some other thing motivating the desire or belief that has nothing to do with their actual performance.

RAEBURN: Now, the - have computers made this a more common phenomenon than it used to be before? Did people always multitask or is it something new, as it seems to many of us to be?

Dr. NASS: They certainly didn't always multitask because it was frequently very hard to do so. One of the things the computer has done is to allow people to pull up many things at once on the screen, the notion of multiple windows enabling that. Of course, we also then have cell phones, which are now getting smarter and allowing us to do multiple applications on those. People frequently have multiple televisions in the home, so it's not just one location where they use television. Print medium, of course, are very mobile. So it turns out that the trend has been growing very, very rapidly and probably wasn't with us, you know, a long time ago, just because there wasn't access to that many media.

RAEBURN: Now, are you a multitasker yourself?

Dr. NASS: I'm actually dreadful at it.

(Soundbite of laughter)

Dr. NASS: I do do it sometimes, and it always impairs me.

RAEBURN: OK. Is that part of what prompted this study?

Dr. NASS: In a way. I was very curious because I live in a dormitory here at Stanford, and I was curious how these kids were doing so many things at once. And so I wondered, jeez, you know, what is their special gift? What is their remarkable talent that I seem to lack? And our research suggests they don't have one. In fact, they're worse at all aspects of multitasking.

RAEBURN: Your students are.

Dr. NASS: Yeah, well, all high multitaskers seem to be really bad at multitasking.

RAEBURN: Now, is there something they can do to get better at it? If they stop multitasking, will their cognitive abilities recover?

Dr. NASS: Well, there's definitely evidence that if they stop multitasking, they'll do better because of all the studies showing that multitasking impairs performance. We're not sure whether these abilities are built in the brain or whether in fact, practice makes them, in this case, not perfect, makes them worse at it. We just don't know that - that's one of the key areas. But there's no question whatsoever that multitasking, especially among those who do it the most, is at the very least ineffective and at the worst, harmful.

RAEBURN: Yeah, tell me a little bit more about the idea that it's harmful. It's one thing to be thinking you're good at it and not being very good at it, but the idea that it might actually harm your thinking ability is a little frightening.

Dr. NASS: It's very frightening to us, and I think the reason it's so frightening is we actually didn't study people while they were multitasking. We studied people who were chronic multitaskers, and even when we did not ask them to do anything close to the level of multitasking they were doing, their cognitive processes were impaired. So basically, they are worse at most of the kinds of thinking not only required for multitasking but what we generally think of as involving deep thought.

RAEBURN: Which is what?

Dr. NASS: So the three abilities we looked at were - the first is filtering: the ability to ignore irrelevant information and focus on relevant information. And I had thought, more than my other two colleagues, that that was a particular gift that high multitaskers had. But in fact, multitaskers are suckers for distraction and suckers for the irrelevant, and so the more irrelevant information they see, the more they're attracted to it.

The second ability is the ability to manage your working memory, keep it neatly organized, be able to - the way I usually think about it is, imagine having very neat filing cabinets where you carefully and quickly place things in the right cabinet, and when you need the information, you immediately know which filing cabinet to go to. They're actually much worse at that.

And finally, the biggest surprise to the two other authors of the study, Eyal Ophir and Anthony Wagner, the biggest surprise was that they're even slower and worse at switching from one task to another. You would've thought that, at the very least, would be the key gift of multitaskers, but they're actually worse.

RAEBURN: So they're really working against their innate abilities, to some extent.

Dr. NASS: Absolutely, and again, we don't know whether they're totally innate, whether they're innate plus learned, or learned. But one way or another, they're putting themselves in situations where at the very least, they're destined to do poorly, and at the worst, they are destined to permanently impair their cognitive processes.

RAEBURN: I'm sure there are listeners desperate to get through to tell us about their experience with this. We're having some problems with the phones…

Dr. NASS: Oh, really. OK.

RAEBURN: …and I can't take a call yet, but we'll hope to fix that and get to that soon. So for those of you who are on hold, stay on hold. We'll get to you as soon as we can get this problem fixed up.

Now, when we talk about multitasking, we can think of a lot of things we do in our lives; for example, being on the computer and listening to music and doing something else. But in the more literal sense, can we - if you've got five windows open at the same time on the computer, is that the same kind of problem, or is jumping from, you know, email to Microsoft Word to something else not as - not quite what we're talking about here?

Dr. NASS: No, that is exactly - and it's precisely a problem. Music, or at least instrumental music, seems to be the one modality that doesn't seem to lead to problems with multitasking. However, all the other ones you mentioned, certainly jumping from playing a game to browsing something to writing a Word document to email, that is definitely the type of activities we're thinking about that, in fact, are very difficult to do, particularly for high multitaskers.

RAEBURN: Do we know much about what's going on in the brain here? Now, I don't think this study addressed exactly what's going on in the neurons, but have other folks looked at that, or have you looked at that in other work?

Dr. NASS: Actually, no one's looked at that yet but my colleagues, Anthony Wagner and Eyal Ophir, are actually going to be doing brain scans of high and low multitaskers to try to figure out, for example: Do high multitaskers, do the pleasure centers of their brain light up when they get more and more information, as opposed to processing it? Can we find things that suggest this ability is learned or plastic or whether it's inborn?

Those are the types of questions we want to ask. They hadn't been asked before because people hadn't worried about what we call chronic multitasking. They were only looking at multitasking in the moment. In other words, when you're doing five things, how good are you at them?

RAEBURN: OK. We're going to try a call here. I'm not sure this is working, but this might be Paul from Long Island. Is that you, Paul?

PAUL (Caller): Yes, that's me. How you doing?

Dr. NASS: Hey.

RAEBURN: Terrific.

Dr. NASS: Hi, Paul.

RAEBURN: Thanks for staying with us. Go ahead with your question.

PAUL: Of course. Recently, I finished up student teaching, so I just graduated. And as I - my collaborating teacher was a woman, and I'm sure you guys know, to be a teacher, you have to multitask all the time, whether you're writing on the board or watching what the kids are doing or, you know, whatever is going on. You always got to be paying attention to five things at once.

So, you know, I had mentioned that to her and she said, yeah. You know, women are much better multitaskers than men are. So, I was curious if we - have we found anything about that with this study?

RAEBURN: Here's a good question that'll start a fight. Go ahead, Clifford.

(Soundbite of laughter)

RAEBURN: What did you find out about this?

Dr. NASS: First of all, congratulations on finishing your student teaching.

(Soundbite of laughter)

The answer is when it comes to media multitasking, the types of tasks we looked at, filtering, memory management and task switching, there is a literature suggesting there are no differences between men and women. However, there is a large literature on - for lack of better term, I call task multitasking or doing things in the real world, where we do seem to see women have advantages…


Dr. NASS: …it just doesn't seem to play out.

(Soundbite of laughter)

Dr. NASS: But it doesn't play out in media, at least. So, that's consolation.

PAUL: All right, thanks a lot.

Dr. NASS: I knew we'd cause trouble with that one. Thanks, Paul.

PAUL: All right. Bye.

RAEBURN: Now, I want to ask you a little bit, Clifford Nass, about some other research you've done that you and I have talked about before, which is human and machine interaction.

Dr. NASS: Sure.

RAEBURN: And - yeah, go ahead. Hang on just a second. We got a clip coming that's going to lead us into that.

(Soundbite of laughter)

(Soundbite of song, "Like a Rolling Stone")

Mr. BOB DYLAN (Singer): (Singing) To be on your own, with no direction home.

RAEBURN: To be on your own with no direction home. Now, you may know…

(Soundbite of laughter)

RAEBURN: …if you've been following the really big news this week, there was some talk of Bob Dylan loaning his voice for a GPS system. I think what he said was that no matter - whether he said turn right or turn left, if he was giving the directions, we'd all wind up on Lonely Avenue.

(Soundbite of laughter)

RAEBURN: But, in any case, what do you think - have you looked at GPS systems and that kind of communication and - would you think Dylan would be a good man for the job?

Dr. NASS: Yes. We have a - actually, a new lab at Stanford focusing on car-related issues. To this particular question, the research suggests that even though Bob Dylan is absolutely marvelous in many different ways, he would be dreadful for a GPS system.

RAEBURN: Oh, man, legions of fans are weeping right now as you say it.

(Soundbite of laughter)

Dr. NASS: Well, he can stay in the car on the radio, at least, or on the iPod. Just as far as directions -

RAEBURN: Just not on the GPS.

(Soundbite of laughter)

Dr. NASS: That's right. The credibility…

RAEBURN: Now, I'm betting you have a real reason, besides the fact that we can barely understand what he says sometimes, for saying that he's - wouldn't be very good at GPS.

But before you answer that, let me just remind people I'm Paul Raeburn. This is SCIENCE FRIDAY from NPR News. All right…

Dr. NASS: Okay…

RAEBURN: …so why would Dylan be a bad idea?

Dr. NASS: The problem is that our brains are built that when we hear a voice, we associate with that voice - especially if it's a person's voice we know - all the characteristics and benefits and negatives associated with that voice.

Now when it comes to navigation, we want someone who's known as being very precise, who's careful, who is alert and attentive to detail, and that's certainly not the image that Bob Dylan portrays.

So generally, in fact, the idea of using famous people - unless those people are famous for exactly the things we would want in a GPS. So, if anyone knew what Hiawatha's voice sounded like…

(Soundbite of laughter)

Dr. NASS: …that would be a great voice for a GPS. But Bob Dylan is best served in other ways.

RAEBURN: Now, tell us just a little bit more about - just briefly tick off a few of the other things you've done in machine-human communications. Then, we can talk about one or two.

Dr. NASS: Well, we have a lot of recent work in the car space, having to do, for example, showing that the voice in the car as being about Bob Dylan. But for happy drivers, they drive much better with the happy voice in the car. But depressed voice - depressed people and sad and upset people actually drive more safely when the navigation system has a subdued voice.

We've been doing work now on disagreeing with robots, one of the - and robots disagreeing with us. One of the beliefs in the robots community for a long time was robots must always do what people say. But as their abilities increase, it might be logical and plausible for robot to disagree and say, hey, you know, I think, you're doing it wrong.

So we've been doing research on how we can get people to be more accepting of that. We've also been doing research on number of voice issues, what voices are good for various activities, including navigation. And, also, a lot of work on new systems for recommendations, how can computers and Web sites more effectively recommend to people.

RAEBURN: Okay, we'll get into as many of those as we can. But we now have the phones back, ta-da. And so, I'm going to take a couple of calls now on multitasking. We're jumping around a little bit here. But let me see what we got. Jesse(ph), are you there?

JESSE (Caller): Yeah, I'm here.

RAEBURN: Go ahead.

JESSE: Just fascinating topic, super interested in this. And I got many questions, but I'll only ask one. I noticed when I was in school many, many years ago, in college, that I had trouble sitting in a lecture and trying to learn the material and take notes at the same time. And this has transferred over into the work world in meetings, you know, etc. Some people seem to be really good at this, and other folks, like myself, are terrible at it. It seems to be that even while I'm focused on this one task or project, I have a tough time, you know, keeping - while multitasking or keeping attention, I guess.

RAEBURN: Let me stop you, Jesse, because we're moving up to a break. But go ahead, Clifford Nass, give him a quick answer if you can, please.

Dr. NASS: So, the quick answer is, people who seem to be very good at, for example, sitting in a meeting and doing emails, etc., are actually very bad at it. As far as the first question, we haven't specifically studied task-related multitasking - that is, writing and learning them and taking notes. But we certainly know that people who are sitting in lectures and texting, chatting, friending, you know, Facebooking, etc., are not doing very well.

RAEBURN: Let me pause for a moment. We'll be right back after this short break.

(Soundbite of music)


We're talking with Clifford Nass, professor of sociology at Stanford University about multitasking, and machine and human communication, and all kinds of interesting things.

Let me take a call from - let's see here, we've got Brian(ph) on Long Island. Do I have you?

BRIAN (Caller): Yes, you do.


BRIAN: Thank you for taking my call.

RAEBURN: Yeah. Go ahead, Brian.

BRIAN: Dr. Nass, the question is that when people are multitasking, what is their ability to accomplish tasks successfully? Do they have a greater success rate or a lesser success rate?

Dr. NASS: They actually have a lesser success rate, which has been established numerous times. What our results are showing is that if they're frequently multitasking, not only do they have a lower success rate when they're multitasking, they actually have a lower success rate when they are not multitasking.

BRIAN: Interesting. The reason why I ask that is that I find that in multitasking, you have to kind of train the brain to be able to focus on entities and take a time slice of each piece. For example, the prior caller had talked about trying to take a lecture and at the same time, write notes. The methodology I use for that is mind-mapping, where I draw up pictures that symbolizes what's being spoken about so that the recall level works much better.

It's kind of what the filing cabinet process you had spoke about. Any comments on that?

Dr. NASS: Yes. The using of multiple media to do the same task - that is, let's say, for example, learning material - we don't actually have a clear handle on what the effects are on the brain. What we do know is that the effects when you're doing different tasks, for example, sitting in a lecture and drawing pictures about the lecture but at the same time, you know, reading something or texting or talking on the phone or chatting, or any of those other activities, those are the ones we really know about.

But you're certainly right. Mind-mapping is a well-established strategy for improving memory.

RAEBURN: Thanks, Brian.

BRIAN: Thank you very much.

RAEBURN: Let's take a call from Sonia(ph) in San Francisco. Welcome, Sonia.

SONIA (Caller): Hi. Thanks for taking my call.


SONIA: My question is in relation to whether multitasking is more prevalent in one generation compared to another - for example, with Gen Y and baby boomers -and if the implications are different for these different age groups?

RAEBURN: That's a great question. My teenage daughter used to keep about 30 IMs going simultaneously. I was amazed.

(Soundbite of laughter)

RAEBURN: Now I understand it's a problem. But anyway, go ahead, Clifford Nass.

(Soundbite of laughter)

Dr. NASS: What we're actually seeing is different patterns of multitasking in different generations. We certainly see among the Gen Yers, the teenagers and 20s of this generation, showing an enormous desire to multitask. What we're seeing among older age groups, which I find fascinating, is the - being forced upon them.

For example, in the workplace, being required to keep multiple chat windows open, etc., not by volition and choice, the way we see in the younger generation. In the really, really young, we're actually also, very surprisingly, seeing multitasking. For example, our recent research has suggested that if women are watching television while they're breastfeeding, the babies are actually spending an enormous amount of time watching TV.

And so, even at that very young age, and then as kids get older, we see kids sitting in front of the TV, but not just sitting in front of the TV, but with toys in front of them and books in front of them. And then in the - what we're seeing more and more, and another one of our colleagues, Roy Pea, is interested in this area: the social multitasking, the idea that for even very young kids, grade school kids, a lot of their social interactions are becoming, you know, four chats at once or four interactions simultaneously.

And so at different ages, we're seeing different types of things, but it seems to be a growing trend in all age groups.

RAEBURN: Thanks, Sonia.

SONIA: Thanks.

RAEBURN: Certainly I think we - can we recommend that women who are breastfeeding listen to NPR instead of watching TV? Does that come out of this research?

(Soundbite of laughter)

Dr. NASS: Yeah, absolutely. They think - I don't know what the babies will get out of it, though. That's the only problem.

(Soundbite of laughter)

RAEBURN: Now, here's a question. These people who are doing all this multitasking, even unknowingly to their own detriment, are they getting some reward out of that? Is there some reason why they keep doing it or want to do it?

Dr. NASS: Well, one of the theories we have that one of the authors on this paper, Anthony Wagner, is very interested in is the idea of a tendency towards exploration versus exploitation. Exploration refers to the desire to just gather more and more information, whereas exploitation involves the focused concentration in information.

So it very well may be that for these high multitaskers, they're getting a tremendous amount of gratification out of just receiving information. And he intends to look at that, among other ways, by looking at the neuronal structures here and looking at pleasure centers in the brain, etc., to see whether they just don't get a kick out of it.

RAEBURN: Very interesting. Jim in Washington, are you there?

JIM (Caller): Yes.

RAEBURN: Go ahead.

JIM: I was wondering if there were any similarities or differences with like, task management issues for people with ADD in the research that you're doing.

Dr. NASS: It's a great question. We haven't explicitly studied ADD and ADHD as an important area. One of the things that we can guess, at least, is if it's true that using multiple media simultaneously is causing these problems - we don't know which is cause and which is effect - then certainly the groups, individuals with ADD who are likely to be finding a great desire to do this sort of quick multitasking are probably advised to really work hard not to do it and instead, at the very least, to switch from a media task to a non-media task, be it walk around, close their eyes, etc.

But this incessant multitasking, to the extent it does, in fact, affect the way the brain works - which we have some evidence for - they would be very well advised not to make their difficulties worse.

RAEBURN: Thanks, Jim.

Now, we talked a little while ago about gender and multitasking and so forth. I'd like to get back on to some of our talk about GPS - we're bouncing around a bit today.

Dr. NASS: Sure.

RAEBURN: Now, you have a story, I think, about BMW and gender and GPS systems.

Dr. NASS: That's right. When BMW introduced their Five Series in Germany, it was an amazing technological feat. It was probably, by far, the most advanced navigation system of its kind at the time. And they put it with a female voice. And German drivers - actually, they had to have a product recall because German drivers refused to take directions from a woman. And this actually was one…

RAEBURN: Of course, American drivers are far more sophisticated than that …

(Soundbite of laughter)

RAEBURN: Since you didn't study them, we'll assume that's the case.

(Soundbite of laughter)

Dr. NASS: I don't want to engage…

(Soundbite of laughter)

RAEBURN: All right.

Dr. NASS: Cross-country comparison. But the idea was that people bring to bear all their social rules, expectations, etc., when they're using technology, particularly voices. And thus, that's why these effects happen.

RAEBURN: Now, this is a profound - is it a profound thing about people's attitudes about gender? Or is it just something about the mechanics of these machines?

Dr. NASS: Well, it's more than about gender. It's about everything. We have done studies, for example, showing that the emotion of the voice in a car matters, that the personality of the voice - if the voice of the car's personality matches yours, you're more likely to take its advice and suggestions.

We've been able to show that emotional-sounding voices by the car are different than non-emotional voices. Voices you're told are coming directly from the car are psychologically different than voices that are coming from a distant way station. So our brains are evolved to treat voices we hear as coming from humans, and applying all of the human rules and heuristics and thus, the fact that it's on a technology, we don't have an on-off switch in our head that says, up, it's technology, ignore all these social characteristics; up, it's human, bring them back again.

RAEBURN: So even if it's one of these very crummy synthesized voices that's very obviously a computer voice, to some extent we still treat that as if that were a human being?

Dr. NASS: Yes. We've done work, for example, showing that even those voices are gender stereotypes. So, for example, when a synthetic voice reads product descriptions, the males will be more trusting of the, quote, male - even though it sounds more like a Martian, I suppose, than a person - male voice and females, more to a female voice. They'll also trust male voices describing stereotypically male products more than females describing those voices, and vice versa. So we have an enormous obsession, excuse me, with the social characteristics of voice.

RAEBURN: I'm going to take another question now on multitasking from Lewis(ph) in Greensboro. Are you there?

LEWIS (Caller): Yes. I'm here.

RAEBURN: Go ahead.

LEWIS: I'm curious about the assertion of no one being able to multitask, and if that also applies to musicians, improvisational people who are able to listen and compose at the same time?

Dr. NASS: Well, first of all, our research doesn't say no one can possibly multitask at all. We're looking for general trends. There is a fundamental difference that we don't fully understand between multi - using multiple media, multiple signals to integrate towards a single goal, as in the case of improvisational musicians, as opposed to doing things.

But what you don't see is you don't see improvisational musicians reading a book and watching TV while they pick up on the score. And I think that's a big difference. It's not related things. It's unrelated things. And again, multitask - the sort of musicians and creative people who are pulling in lots of different things to bring together a single image aren't, you know, Facebooking while they're doing it.

RAEBURN: Thanks, Lewis.

LEWIS: But they may be able to carry on a conversation while still playing a song.

Dr. NASS: That - there's less evidence of that, actually. Listening to music, yes. If you're listening to instrumental music only, there's evidence that that isn't affected. But the minute, for example, there are words or you're really trying to create music, it's very likely that they were impaired in doing that.

LEWIS: Okay. Well, I'm wondering if anything could train you towards that, like Dylan playing the guitar and harmonica.

(Soundbite of laughter)

Dr. NASS: Well, you know, at least he's playing the same song. I don't know how he would do if they were different songs.

RAEBURN: Thanks, Lewis, for the question.

LEWIS: Thank you.

RAEBURN: I just - as we're getting near the end of the segment here, what are the recommendations that come out of this? What should we do? Should we stop multitasking? Do we have to go live in a cave to manage that?

(Soundbite of laughter)

Dr. NASS: Well, the first question is - especially people who chronically multitask should certainly do it much less, whether or simply because they're bad at it, they're particularly bad it, or in fact whether it's actually making them worse not only in multitasking, but dramatically affecting the way their brain operates.

As far as whether we have to go to a cave to do it, on the one hand, there's certainly an enormous and growing stream of information, the amount of bits coming and the number of opportunities to multitask is only growing enormously with the growth of, you know, now handheld devices, that you can do 20 things with.

But I think people can try to just not do it as much, very simply.

RAEBURN: Okay. And it's OK to listen to Bob Dylan. We can settle that issue once and for all.

Dr. NASS: Absolutely, as long as he's not telling me where to go.

RAEBURN: Thanks so much for being with us. I've been talking with Clifford Nass, professor of sociology at Stanford University, about some very fascinating work.

Thanks for being with us.

Dr. NASS: My pleasure. Thanks so much.




