The Necessity of Multitasking

Multitasking has gotten a bad rap. Decades of studies have been conducted that point out the many costs of multitasking and the negative outcomes it can have (see Multicosts of Multitasking for a discussion of the brain regions involved).

In many of these studies, participants complete a dual-task paradigm in which performance on a primary task (task A) is compared when it is done on its own versus when it is done at the same time as a concurrent task (task B). Usually, performance on task A takes a hit when it is done at the same time as task B.

However, real-life contexts exert different types of pressures than laboratory studies. It may be true that doing two tasks separately produces the best results, if time is unlimited. But the real world often imposes time and other constraints. Suppose you only have 30 minutes to accomplish two tasks. The question then becomes: Is it more efficient to focus on task A first, and then focus on task B? Or is it better to multitask, carrying out both tasks at the same time?

The answer depends entirely on the specific demands of the tasks at hand. There is no doubt that when doing both tasks at the same time, one cannot be as efficient in each task as when doing them separately. But if we think about overall efficiency, considering the importance of the tasks and the time constraints, then the answer is not as clear.

Consider a scenario in which you are washing dishes while talking on the phone with a customer service representative. It is certainly possible that by actively washing dishes, some aspects of your phone conversation may be impacted: You may take an extra second or two to respond to a question; your responses might not be perfectly thought out; your overall conversation may take longer. But it is difficult to imagine that you will fail at accomplishing the goal you had in mind with customer service. Similarly, as you talk with the customer service representative, your dish-washing performance may suffer a bit too. You might rinse the dishes a little slower than usual, or you might take longer pauses between dishes as you shift your focus back to the conversation. But again, it is difficult to imagine that you will fail at washing dishes (for example, by breaking a dish, or leaving some dishes unwashed). Most likely, you will just take a little longer to wash the dishes than usual.

But when you think about your overall efficiency, it is likely that you will not only accomplish both tasks well (or well enough), but that you will do them in less time than if you had completed them separately. In many cases it is not only OK to multitask, but it can be a more efficient way to accomplish multiple things in a limited amount of time.

If you break down what you do throughout your day, you will find that you are very often multitasking in some way. Even when you are focusing closely on a specific task, you are also likely having spurious thoughts about your day (i.e. mind wandering), or you may have musical imagery (i.e. earworms). You might also be shaking your leg, fidgeting with your pen, or twirling your hair. Meanwhile, you are also simultaneously engaged in unconscious behaviors like breathing, blinking, and monitoring the environment and your internal bodily cues. People cannot do just one task at the exclusion of all other activities, because the human brain is an intrinsically multisensory, multitasking organ.

So why does multitasking get such a bad rap? As mentioned above, there are measurable costs to performance and reaction time when engaged in multiple tasks compared to a single task. The more difficult the tasks are, the higher the costs of attempting to do them simultaneously will be. When it is really important to do a task well (e.g. writing an important email, listening to a friend in need) and time is not a constraint, then it is wise to focus on that one task only. In a scenario where one task (e.g. driving) requires focused attention and carries high risks, it can be extremely dangerous to engage in a distracting task like texting that takes one's eyes off the road for seconds at a time. In certain important and high-risk contexts, whether driving or crossing a street, it is important to be aware of how impaired we can become when distracted by our devices.

But in many other day-to-day situations, especially when you have limited time to accomplish multiple low-stakes goals, multitasking may be the way to go.