STUDY FINDS TEENS SPEND A THIRD OF SCHOOL DAY ON SMARTPHONES, LINKED TO WEAKER ATTENTION AND IMPULSE CONTROL

A new peer-reviewed study published in JAMA is adding weight to the growing debate over smartphones in schools.

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Researchers found that middle and high school students spend roughly one-third of their school day actively using their phones, with frequent checking behavior linked to weaker attention span and reduced impulse control.

Rather than relying on surveys or self-reported estimates, the study used real-time tracking data collected hour by hour over a two-week period. That methodology allowed researchers to isolate patterns of repeated phone checking and examine how those micro-interruptions correlated with cognitive performance.

The results suggest that it is not just screen time in aggregate that matters, but the behavioral rhythm of constant digital interruption.

A PATTERN OF CONSTANT INTERRUPTION

Students in the study were found to check their phones dozens of times throughout a typical school day. These interactions were often brief — a notification glance, a short scroll, a quick reply — but they accumulated into substantial time on device.

On average, about one-third of school hours involved active phone use. Social media and entertainment apps accounted for more than 70 percent of that activity, according to lead author Dr. Eva Telzer. Messaging platforms, short-form video apps, and social feeds dominated usage patterns.

The research team emphasized that the structure of smartphone engagement — frequent, fragmented, notification-driven — may disrupt sustained attention. Each glance or swipe represents a cognitive shift away from the classroom task. Even if a student returns quickly to the lesson, the mental cost of task switching can linger.