Is doing nothing
really a waste of time?

When I'm not doing anything, I feel a little uneasy.

A few minutes waiting for the train. The pause after finishing a piece of work. The moment after studying. Before I know it, I've picked up my phone and filled the gap.

"Time spent doing nothing is wasted." In today's life, that feeling may be completely natural.

But follow the research, and a slightly different picture appears. During rest without new input, or time with low demands on attention, researchers have reported things linked to memory consolidation, creative problem solving, and thinking about the future.

That said, it isn't as simple as "zone out for 20 minutes and it's good for your brain." The durations and conditions used in studies all differ.

1. Ten minutes right after learning stayed in memory

Let's start with a relatively clear study.

Dewar and colleagues had older participants learn a story. Afterward, in one condition they took ten minutes of wakeful rest; in the other they did a spot-the-difference task. In the rest condition, memory was better not only shortly afterward but also seven days later.^[1]

The important thing is that they didn't study longer.

After taking in new information, they stayed quiet instead of filling their heads with something else. That time may have helped them retain the memory.

This doesn't mean "rest and you'll remember anything." It was a specific memory task. Still, the idea of not jumping straight to the next input after learning has experimental support.

2. Ideas don't only come from thinking harder

On creativity, there's an interesting result.

In an experiment by Baird and colleagues, participants worked on a task thinking up creative uses for objects, then were split into several conditions: a demanding task, an undemanding task, rest, or no break.

The biggest improvement on the creativity problems they had seen before came in the group that did an undemanding task for about 12 minutes. That group also reported more mind wandering.^[2]

The phenomenon of a problem getting solved after you step away from it is called incubation. A meta-analysis by Sio and Ormerod found an overall incubation effect, but its size depended on the type of problem and on what people did during the break.^[3]

3. When we zone out, we think about the future

Mind wandering is often described as "failing to concentrate."

But look at what's in it, and it isn't just noise unrelated to the present.

Research by Baird and colleagues showed that thoughts during mind wandering are often future-oriented, and linked to "autobiographical planning": thinking about your own future goals.^[4]

For example, while walking or showering, a thought like "next, I'll do this" sometimes suddenly comes together.

Of course, not every daydream becomes a useful plan. Still, it's interesting that when the mind leaves the task at hand, it sometimes reworks the past and simulates the future.

4. A "resting" brain isn't switched off

This topic often comes up together with the default mode network.

Brain imaging research came to show that even when we aren't paying close attention to an outside task, certain brain regions are active in an organized way. In 2001, Raichle and colleagues framed this idea as a "default mode."^[5]

Later reviews summarized that this network is linked to inward-facing cognition, such as recalling autobiographical memories, imagining the future, and taking other people's perspectives.^[6]

From the perspective of education and development, too, researchers have suggested that reflective processing away from outside attention may matter.^[7]

But claims like "the DMN is active, so the brain is recovering" or "activate your DMN and you'll get smarter" are a leap.

What we can say is more modest: even when we look like we're doing nothing, the brain keeps processing internally.

5. So is scrolling your phone "rest" too?

Here we need to be clear about what the research can and can't tell us.

Dewar's memory study used quiet wakeful rest, with older adults. In Baird's creativity study, the effect appeared with an undemanding task. Neither study tested looking at social media or videos on a phone.

So we can't say "looking at your phone always cancels the effect." But we also can't say, from these studies, that "you get the same benefit from rest while on your phone."

If you want to put this into practice, a reasonable takeaway isn't a "no phones" rule, but leaving a little time when you don't keep adding new input.

6. Idle time has costs too

Reading this far, it's tempting to think "the more you zone out, the better." But mind wandering has clear costs too.

A review by Smallwood and Schooler concluded that while mind wandering is linked to creativity and planning for the future, it's also linked to errors and worse performance on the task you're doing.^[8]

And a study by Killingsworth and Gilbert, which tracked people's daily lives through their smartphones, reported that a mind wandering away from the current activity was associated with lower happiness.^[9]

In other words, idle time isn't a cure-all in itself.

• Rest quietly right after learning
• When stuck on a creative problem, step away to something undemanding
• Have time, such as a walk, that doesn't take too much of your attention

It's this kind of context that matters.

7. There's no magic in "20 minutes"

You often see numbers like "zone out for 20 minutes."

But in the key studies here, Dewar used 10 minutes and Baird used 12 minutes. At the very least, these studies didn't show that "20 minutes is optimal."

So in practice, rather than "sticking to 20 minutes," something closer to the research would be starting with around 10 minutes of low-input space.