Does having your phone nearby hurt studying? The brain drain study, checked again

An hour at the table, and one buzz after another

Picture a man training to be an electrician, with a licensing exam in nine weeks. He gets home after ten hours on a job site and opens the code book at the kitchen table. His phone lies face down next to it.

It buzzes. The group chat is arguing about a game. He answers once, then twice, then watches a short video someone sent. When he gets back to the page, he reads the same paragraph again.

An hour later he closes the book. He was at the table the whole time. He could not tell you one rule without opening it.

Two small choices shape every study session like this one. Where is the phone? And what do you do in the ten minutes after you stop? One of them has better evidence than you might expect. The other has worse evidence than the headlines claimed.

The 2017 brain drain study, and the 2022 repeat

You may have heard that a phone nearby makes you think less clearly, even when it is silent. That idea comes mostly from one paper.

In 2017, Ward and three colleagues ran two experiments on what they called "brain drain." In the second, people did tests of working memory and attention. Their phone sat on the desk, in a pocket or bag, or in another room. The authors reported that "the mere presence of these devices reduces available cognitive capacity." They said the cost was highest for people who depended most on their phones.

In 2022, Ruiz Pardo and Minda ran a direct repeat of that second experiment. It was preregistered, which means they published their plan before collecting data, so they could not tweak the analysis later. They used the same phone locations. Their verdict: "the 'brain drain' effect did not replicate."

A 2020 study by Hartmann and colleagues tested a phone on the desk against short-term memory. It also tested remembering to do something later. They "found no overall effect of smartphone presence."

So here is where it stands. One 2017 study found an effect of a phone just being there. A careful repeat in 2022 did not.

What does cost you: picking it up

The finding that holds up matters more than the headline did.

Glass and Kang (2019) ran their study in a real college course. In half the lectures, students could use laptops and phones. In the other half, they could not. The same students sat through both kinds, which makes the comparison fair.

On quick quiz questions during class, devices made no difference. Students seemed to follow fine. The cost showed up later, on the unit exams and the final. Divided attention "reduced long-term retention of the classroom lecture." And scores were lower for material from device lectures "both for students who did and did not use electronic devices during that class."

An earlier lab study points the same way. In a simulated classroom, Sana, Weston and Cepeda (2013) found that students who multitasked on a laptop scored lower on a later test. So did students who could simply see a multitasking classmate.

Notice the shape of that result. In the moment, nothing seemed wrong. The loss showed up later, on the exams. We think that is the most useful thing on this page: a session can feel fine and still not stick.

This describes study research only. If you have ongoing trouble focusing that goes beyond phone habits, talk to a health care provider.

Where to put the phone, and what to do after the block

The chapter Attention, Phones and Breaks in Stop Rereading turns this into two tools, both badged PROMISING.

The Phone in Another Room is the first.

1. Choose your block length before you start, somewhere from 25 to 50 minutes.
2. Tell anyone who might need you when you will check messages next.
3. Put the phone in another room. If you cannot, zip it into a bag out of reach.
4. Time the block with a kitchen timer or the stove clock.
5. Keep a scrap of paper for things to look up later. Write the urge down instead of grabbing the phone.
6. Check the phone during your break, not before.

The After-Study Walk covers the ten minutes after. Scrolling feels like rest, but it is new input. In a 2019 review, Loprinzi and colleagues found exercise in the period after learning helped memory, while exercise during learning slightly hurt. In a 2012 study by Dewar and colleagues, people who rested quietly for 10 minutes after hearing a story recalled more than people who played a game. A 2026 review by Parra, Zhang and Radvansky adds a caution: many studies found nothing in healthy young adults, and the pooled effect was small. So the tool is a 10 to 15 minute easy walk with no earbuds, or ten quiet minutes with your eyes closed. If you have a health condition that affects exercise, ask your doctor what kind of walk suits you.

One study often quoted for walking breaks is about something else. Oppezzo and Schwartz (2014) found walking boosted creative ideas. It did not test memory.

If the phone is not your only screen, our page on using ChatGPT to study covers the newer kind of distraction, one that does not feel like a distraction at all.