What is multitasking?

According to Edward Hallowell multitasking is the

mythical activity in which people believe they can perform two or more tasks simultaneously as effectively as one

Very often that’s not what we’re really doing though. Often we’re just engaging in high frequency context switching - a rapid toggling among tasks rather than simultaneous processing. In other words we’re shifting our attention from one task to another and back again. Each context switch consists of two stages, “goal shifting”, which is where we decide what to do next, and “role activation”, where we switch to the set of rules required for the new task. We’re

compelled to restart and refocus

Of particular relevance today is what Linda Stone calls Continual Partial Attention. This is the phenomenon of handling multiple information sources by skimming the surface of the incoming data, picking out the relevant details, and moving on to the next stream. The number of sources we interact with is increasing and these sources are increasingly being used concurrently. According to the Kaiser Family Foundation the amount of time spent using different media concurrently almost doubled from 1999 to 2005.

Can we truly multitask?

It is possible to do more than one task at once but the tasks have to be simple and familiar, and there can’t be too many of them. For example, if you’re driving, it is possible to hold a conversation with your passenger at the same time. However, changing gear is a complex operation involving the intricate coordination of two feet and a hand, and when you’re first learning to drive you won’t be chatting whilst you’re doing it. Eventually, though, it becomes a familiar task which is performed subconsciously. Facebook and a movie though, is more complex. It’s not really Facebook and a movie at all; it’s more like Facebook then movie, then Facebook then movie, then Facebook then movie.

Certainly, most things that are unfamiliar, or that we deem creative or worthwhile, or that we call work in the post-industrial age, will suffer or become impossible when we try to include them as part of a multitasking activity. It’s also true that many simple or familiar things can be performed better when focus is applied. While it’s true that driving can easily be combined with listening to your passenger or the radio, proper, high quality driving is an active, participatory process. If you’ve ever had a track day or driven on blue lights or better yet, listened to commentary whilst being driven on blue lights, you’ll be aware of the focus, attention to detail and information processing that’s required. And yet most of us, most of the time, drive from A to B in a blur, with little to no recollection of the driving process. It works well enough; usually. Driving is one of those activities for which “good enough” is usually good enough.

What’s the problem then?

The fact remains though that sometimes sometimes “good enough” turns out not to be. You’re four times more likely to crash if you’re using your phone and interestingly experienced drivers are, in general, slower to react to brake lights and traffic lights.

So, multitasking makes us error-prone. This often manifests itself as a reduction in quality rather than discrete or complete failure. Equally important, we’re less efficient when we multitask. We lose significant amounts of time when we switch between multiple tasks and we lose even more time if the tasks are complex, often suffering up to a 40% loss in productivity.

It is certainly difficult, and possibly impossible to learn new information while engaging in multitasking. Students who engaged in more multitasking reported more problems with their academic work. We also tend to lose our ability to spot things in our periphery and it has even been shown that multitasking is accompanied by a rise in stress hormones. It seems clear then, that multitasking impairs many of our cognitive abilities.

How Is the Brain Affected?

According to Pashler multitasking causes dual-task interference through three possible mechanisms:

  1. Capacity sharing. This is when a multitude of complex tasks consume too much of a mental resource to allow other tasks to continue.
  2. Bottlenecking. This is when a single, discrete mental resource is available for use by only one process at a time.
  3. Cross-talk. This is when similar sensor inputs route simultaneous and conflicting signals to the brain. Alternatively, it’s when outputs confuse the processing of other tasks.

Demographically speaking, contrary to popular belief, there’s very little evidence of any gender differences in multitasking ability. There’s also little evidence that younger people are better at it, although they do seem to be better at filtering out which information is worthy of their attention.

So why do we bother?


If we aren’t very good at multitasking, why do we bother? The fact is, even though we can’t do it, we want to do it, we think we can do it, and we can’t resist trying to do it. Multitasking makes us look busy and capable and efficient; in short, it makes us look good. Consequently it can be difficult to admit that we’re not very good at it, or that it doesn’t work. This is compounded by the fact that it’s easy to convince ourselves that rapid context switching is in fact true multitasking. In fact, the people who multitask the most are actually the least able multitaskers. Perhaps the most dangerous aspect of multitasking is that maintaining focus is hard; multitasking gives us a great excuse to procrastinate by dealing with urgent but unimportant alternative tasks. It’s often an excuse to pursue a more interesting or fun activity.

Is There a Solution?

Whilst it is true that the brain is incapable of performing multiple complex tasks at one time, even after extensive training, it is also true that people can be trained to switch tasks more efficiently.

The most important realisation is that your ‘to-do list’ is really a tree. You have long-term life goals, which require the completion of complex projects composed of smaller sub-projects which in turn are composed of individual actionable tasks. You can’t “build an ice-cream business” but you can “Google pistachio suppliers in Wakefield”. It’s these leaf nodes, the small, independent actionable tasks, which you need to add to your attention queue. Note that these things can be placed into a queue and don’t need to be in a tree. Once they’re in a queue you can deal with them one at a time, in some kind of order. Viewing your to-do list in its original tree form makes this very difficult.

Picking the appropriate granularity for your tasks is the next step. Get a feel for how long your optimal focused time is and try to split your projects into tasks of about this length. This allows you to focus on one task to completion before switching to another or taking a break. If you want to train up your focus, you can use a timer to steadily increase the time you focus on a task before taking a break.

Building strategies for handling distractions is the final component. Always have a ‘catch’ with you, whether it be a paper notebook, a phone app or a plain text document open on your computer. Use it to catch any incoming distractions that you don’t absolutely have to deal with right now. Catch it and forget it until your next break. Your strategy should be to recognise distractions for what they are, eliminate them where possible and schedule dealing with them where you can’t eliminate them. Your last resort should be an immediate response to a distraction. Included in distractions are things like email and Facebook. Schedule time slots to handle these things and make sure you turn off notifications.

William James described the youthful mind as having

an extreme mobility of the attention [that] makes the child seem to belong less to himself than to every object which happens to catch his notice.

For some people, James noted, this challenge is never overcome; such people only get their work done

in the interstices of their mind-wandering

It turns out that the quickest way to do many things is to do only one thing at a time.