Does using your phone in class affect your grades? New trial

If you've been wondering whether using your phone in class affects your grades, the best answer so far is yes, a little. A randomized trial of 16,683 college students, published in Science in October 2026, found that collecting phones at the start of every lecture for a semester raised grades. The average gain was modest. Students who were struggling or in their first year gained noticeably more.

Two details matter for what you do next. The gain came from physically taking the phone away, with a box at the front of the room, so nobody had to rely on willpower. And it didn't shrink students' overall phone use. It protected lecture time and nothing else.

What the trial did with 1,000 wooden boxes

The study, by Sungu, Choudhury and Bjerre-Nielsen, ran across 10 higher education institutions in Odisha, India, where more than 70% of people aged 15 to 29 own a smartphone, according to the Science paper. Students in the ban group handed in their phones at the start of class. The control group carried on as usual.

The scale is what makes it unusual. It involved 742 teachers, more than 2,300 courses and about 1,000 wooden deposit boxes made from recycled materials, used at every lecture from February to May 2024, as The Educator reports. Randomization happened across 420 department-and-year groups, according to an appraisal by Nabu Science.

It wasn't absolute. A few students with emergency needs, such as caregiving, were allowed to keep their phones, as Greg Ashman noted on Filling the Pail.

So, does using your phone in class affect your grades?

Standard deviations are hard to feel, so the authors offered benchmarks from earlier meta-analyses, reported by The Educator. A typical large-scale education trial produces about 0.05. The median education trial produces about 0.10. The gap between an average and a very good teacher over a year is about 0.20.

So boxing phones did a bit better than most big education programmes, and delivered a little over a third of what a year with a much better teacher would. That's a respectable result for an intervention that costs a wooden box. The grades were also mostly based on externally marked exams, so lecturers being nicer to phone-free classes is an unlikely explanation.

Struggling and first-year students gained the most

The gains were larger, and statistically significant, only among students with lower prior grades and first-year undergraduates, according to EurekAlert!/AAAS and the SSRN working paper. Higher performers, postgraduates and STEM students saw minimal effects. As a result, the grade gap between students narrowed.

Attendance didn't change. Students weren't turning up more often, so the authors put the gain down to better attention and classroom dynamics during the lectures themselves.

Students liked the ban more after living with it

Students who went through the ban became more supportive of phone restrictions and less keen on unrestricted access, The Educator reports. The main downside was a small rise in fear of missing out, mostly among male students.

Plenty of things stayed flat. The SSRN abstract reports no change in overall wellbeing, academic motivation, overall digital use or online harassment. Students also didn't feel they were learning more, even though their grades say they were.

Classroom spot checks found less chatter and disruption, less phone use and more engaged teachers in ban classrooms. Oddly, students there "appeared more distracted" to observers, while not reporting feeling more distracted. These checks were exploratory, so I wouldn't read much into either direction.

Why the result is solid but a bit fragile

This is a well-designed, very large trial, and the Nabu Science appraisal rates the main result "Supported". It also calls it "fragile". The reasons are worth knowing before you quote it at your lecturer.

• The lower bound is close to zero. The confidence interval runs from 0.003 to 0.144, so the true effect could be tiny.
• The test choice isn't explained. The paper uses a one-sided statistical test without saying why, according to the appraisal.
• The subgroup findings are softer. The bigger gains for struggling and first-year students come without formal interaction tests or corrections for running many comparisons.
• The survey is a slice. Attitude and wellbeing results come from 2,557 of the 16,683 students (15%), and about half of the 5,109 responses were filtered out, as Pedro Bem-Haja points out in his eLetter in Science.
• It's one place and one level. The trial ran in one Indian state, and the researchers stress it covered higher education only. Schools need their own research, says the University of Copenhagen.

The appraisal's overall verdict is fair: the trial credibly shows a modest gain, and whether it holds outside Indian universities is the big open question. The full paper may answer some of these points in detail, and I'd treat the subgroup numbers as a strong hint more than a settled fact.

How to run your own phone-free lecture

Most lecturers won't hand out wooden boxes. You can copy the part that seems to matter, which is the phone being out of reach for the whole session. You may have read that a phone's mere presence on the desk drains your thinking. This trial didn't test that idea. It tested access, so access is what to remove.

1. 01
   Put it out of reach

   Zip it into a bag pocket or your coat, which is the closest match to a box, instead of leaving it face-down on the desk.

2. 02
   Start where it pays most

   If you're in first year or your marks are slipping, that's where the trial found the gains, and if you're already doing well, expect little change in your grades.

3. 03
   Give it a few weeks

   Students in the trial warmed to the rule after living with it, so judge it after a month of lectures, not one awkward hour.

4. 04
   Schedule your check

   Pick the break or the end of the lecture as your phone moment and tell anyone who might need you urgently when that is.

5. 05
   Keep real exceptions

   If you have caregiving or other emergency duties, keep the phone with you, as the trial allowed.

If you take notes on a laptop, the same logic applies to the browser. Course pages and messages can be useful in a lecture, while a Reels or Shorts tab rarely is. If short videos are your usual escape, this look at short-form video and attention span is a good place to start.

For lecturers weighing a policy, one big trial now suggests that collecting phones is cheap, modestly effective and more popular with students once they've tried it. The biggest beneficiaries are the students most at risk of falling behind.