Less mobile internet, better attention in a trial.
A two-week block improved attention-test performance, but only a quarter met the study’s adherence target.
The 30-second takeaway
Blocking smartphone internet for two weeks improved sustained attention and self-reported well-being in this trial. Calls, texts and internet on other devices remained available. The practical catch is substantial: only 25.5% of participants kept the block active for at least ten days. This demanding intervention is not the same as simply silencing a few notifications.
Adherence and follow-up were incomplete. Attention-test and questionnaire changes do not establish a clinical treatment effect or a lasting benefit.
What researchers found
Standardized attention change
A small average test-score change, scaled to variation between participants’ changes. Pooled before/after estimate (d_z); not a 23% improvement or the randomized between-group effect.
Met the adherence target
119 of 467 participants kept the block active for at least 10 of 14 days.
What the experiment tested
An app blocked both mobile data and Wi-Fi on the phone. Attention was tested directly; well-being came from questionnaires.
A promising result with friction
Randomized timing strengthens inference, but incomplete participation limits how broadly the result applies.
The original publication
Blocking mobile internet on smartphones improves sustained attention, mental health, and subjective well-being
Noah Castelo et al.
PNAS Nexus · 2025
- PubMed ID
- 39967678
- Record checked
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