Credit: Pexels
University of California, San Francisco investigators measured smartphone app activity during school hours among US adolescents and reported an average of 1.16 hours of use, with social media apps taking up the most time.
Adolescents aged 13 to 18 years are estimated to spend more than 8.5 hours daily on screen-based entertainment. Smartphone use has been associated with poor physical health, mental health, and academic outcomes.
Nearly all US public schools have a smartphone policy, but compliance is difficult to enfo…
Credit: Pexels
University of California, San Francisco investigators measured smartphone app activity during school hours among US adolescents and reported an average of 1.16 hours of use, with social media apps taking up the most time.
Adolescents aged 13 to 18 years are estimated to spend more than 8.5 hours daily on screen-based entertainment. Smartphone use has been associated with poor physical health, mental health, and academic outcomes.
Nearly all US public schools have a smartphone policy, but compliance is difficult to enforce and objective evidence about use during school hours has been limited. Few investigations have measured app activity during school using passive sensing technology rather than relying on self-reports.
In the study, "Smartphone Use During School Hours by US Youth in the Adolescent Brain Cognitive Development Study," published in JAMA, researchers used passive sensing technology to measure smartphone usage in schools in a diverse sample of adolescents.
The sample included 640 adolescents around the age of 15 years. Male participants accounted for 59.2%, and female participants accounted for 40.8%. Data were collected using the Effortless Assessment Research System phone app.
Adding up the app minutes
Adolescents spent a mean 1.16 hours using smartphones during school hours. Social media, video, games, communication, and entertainment ranked as the top five app categories, with the greatest time spent on social media apps at around 30 minutes, followed by video apps such as YouTube for around 15 minutes, and games for about another 15 minutes.
Researchers conclude that US adolescents, on average, spent more than an hour using smartphones during school, with social media use accounting for most of that time.
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More information: Jason M. Nagata et al, Smartphone Use During School Hours by US Youth in the Adolescent Brain Cognitive Development Study, JAMA (2026). DOI: 10.1001/jama.2025.23235
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Citation: Smartphone use cuts into school hours, with social media leading the way (2026, January 7) retrieved 7 January 2026 from https://phys.org/news/2026-01-smartphone-school-hours-social-media.html
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