The Multitasking Myth: Doing Everything at Once in ADHD

Some afternoons these are open on my screen: a half-finished strategy document, a data dashboard, two separate conversations, and four tabs I opened with “I'll read it in a minute.” I write a sentence in the document, answer a message, look at a number on the dashboard, go back to the document.

In those hours I feel very fast. In the evening there are three paragraphs in the document.

For a long time I described this to myself as “I'm good at multitasking.” When I sat down to a single task I got bored; when I kept five going at once I came alive. It took me quite a while to see the difference between coming alive and making progress.

The brain does not do it at once, it goes back and forth

In psychology, most of multitasking is studied under the heading “task switching,” because in two tasks that demand attention the mind does not really run in parallel. One is dropped, the other is picked up, then the reverse.

The experiments of Rubinstein, Meyer and Evans measured the price of this back and forth. When participants switched between two tasks, they were slower than when they repeated the same task. The switching cost grew with tasks whose rules were complex and shrank when the task was cued in advance. The authors explained this process with a two-stage model of executive control: first shifting the goal, then bringing the rules of the new task into play (Rubinstein et al., 2001).

These two stages felt very familiar to me. When I answer a message and return to the document, it is not enough to see the document. I have to rebuild the answer to “what was I trying to say in this paragraph?” In the glossary this is called switching cost.

Preparing does not wipe out this cost entirely. Monsell, who reviewed the task-switching research, sums up that the switching cost shrinks when there is an opportunity to prepare, but does not disappear (Monsell, 2003). So even if I plan “I'll just take a quick look and come back,” every return has a rent.

Multitasking feels like a skill. When measured, it turns into a bill.

The objection “But I'm used to it”

I made this objection to myself a lot: if I multitask constantly, I must have become skilled over time.

A frequently cited study on this found the opposite. Ophir, Nass and Wagner reported that people who use many media at once are more easily affected by irrelevant stimuli and by irrelevant information in memory, and also performed worse on a task-switching test (Ophir et al., 2009).

I have to be honest here, because the story does not end there. Wiradhany and Nieuwenstein tried to replicate this finding in two separate studies; only a small fraction of fourteen tests came out significant. The meta-analysis in the same paper found a weak relationship between heavy media multitasking and distractibility, and this relationship lost its significance once the effect of small studies was corrected (Wiradhany and Nieuwenstein, 2017). So there is not enough evidence to say “multitasking damages the brain.” But there is no evidence at all for saying “you become skilled as you multitask.”

Are there people who are really good at multitasking? There are, but very few. Watson and Strayer examined two hundred people who did a demanding mental task while driving in a driving simulator; the proportion of those who suffered no loss of performance in the dual task was 2.5 percent (Watson and Strayer, 2010). I have no data to suppose that I am among that 2.5 percent. Probably you do not either.

Where ADHD sits in this

In this part I want to separate what is known from what is not.

What is known: a meta-analysis combining studies of executive functions in adult ADHD found a moderate difference in the ability of mental set shifting. In the same analysis there were differences of similar size in inhibition and verbal fluency, and also in areas that are not counted as executive functions, such as response consistency. The authors note that the difficulties in adult ADHD may not be limited to executive functions alone (Boonstra et al., 2005).

What is not known: I could not find a strong study that directly measures, at work, within a real day, how much more adults with ADHD lose from multitasking than other people. So I will not write a sentence like “the cost of multitasking is twice as high in ADHD.”

The reasonable conclusion I draw from what I do know is this: switching itself is expensive for everyone, and in ADHD the mental tools that pay that price are already strained. The working memory that is supposed to hold the “where was I” information when I drop a task and return is easily wiped when one more message arrives along the way. I described separately how switching feels in my body in the article on difficulty with transitions; here I look at the matter more from the workflow side.

So why is it so tempting

Because a single task, especially a long and quiet one, creates a kind of stimulus hunger in me. Opening one more tab, looking at one more message satisfies that hunger for a few seconds. In the glossary it is called stimulus hunger, and in the article on stimulus seeking I explained why the arousal level is so decisive in ADHD.

The bad part is that the aliveness I feel while moving back and forth between five tasks closely resembles the feeling of really getting work done. When I get up from the screen I am tired, I have had a busy day, and almost nothing is finished.

So I no longer ask myself “how busy was I?” I ask, “which task moved forward a step?”

Reducing switching without forbidding it

A day condemned to a single task does not feel sustainable to me. The approach I find worth trying is to take switches out of randomness and make them few and planned.

One main task, one side lane. The main task is a single thing that demands attention: the strategy document, an analysis, writing. The side lane is something that does not use the same mental channel and satisfies stimulus hunger: wordless music, an object I can play with in my hand, working standing up. I take the stimulus not from a second task but from the body and the environment.

Leaving messages at the door. I open conversations at set hours of the day, one after another. In between, notifications are off. This one change reduces the daily number of switches seriously. I gathered the details of tidying notifications and tabs in the article on digital clutter.

A parking note. If I have to drop a task, before dropping it I write a single sentence: “In this paragraph I was comparing competitors' pricing, the next step is to add the table.” The second stage in the model of Rubinstein and colleagues, that is, the job of rebuilding the rules, I do when I come back not from my mind but from the paper.

A conscious jump. On some days I cannot stay on a single task, and I accept that. On those days I pick two tasks and switch between them deliberately at a set interval, for example every half hour. Going back and forth between two tasks by the clock, instead of jumping among five by impulse, at least lets me decide the number and direction of the switches.

Switch counter. For one day, draw a line on a piece of paper every time you move from one task to another. Do not try to change the number, just count. When most people see that number in the evening, they explain to themselves why the day passed so full and so empty.

The hidden multitasking on the meeting screen

Online meetings are the most insidious multitasking area for me. The camera is on, my face is on the screen, but in another window I am writing a reply to a message. Nobody sees, and I say “I'm listening anyway.”

Then someone asks me a direct question and I do not know what was said in the last two minutes. At that moment I have both missed the question and left the message I was writing half finished. I come out lacking in both tasks.

Now I am trying a rule in meetings: apart from the meeting window, only the notes file is open. If my hand wants to do something, I take notes, doodle on paper or summarize what the meeting says in my own sentences. This both meets some of the stimulus hunger and keeps attention inside the meeting. If there is something I missed at the end of the meeting, asking “could you clarify this part in a sentence?” is also far cheaper than correcting a two-hour misunderstanding.

Where multitasking is innocent

Not every doing-together is bad. If one of the two is an automated task that does not need attention (listening to a podcast while walking, talking on the phone while folding laundry), there may be no serious loss. The problem starts when two tasks that both demand thinking are run at the same time.

For me the distinction is this: if one of these two tasks does not make me think at all, I am comfortable. If both make me think, I am not actually doing them at the same time. I am just doing both of them halfway.