Social media apps are the main content. The effect of state laws governing phone use at school “remains to be seen,” says the paper’s senior author.

U.S. adolescents spend more than one hour per day on smartphones during school hours, with social media accounting for the largest share of use, according to research published today in JAMA. The findings have relevance for educators, parents and policymakers. 

The study reflects the behavior of 640 adolescents ages 13-18. They and their parents had consented to have software placed on their Android cellphones that allowed use to be passively monitored. Usage was measured between September 2022 and May 2024.  

“These apps are designed to be addictive. They deprive students of the opportunity to be fully engaged in class and to hone their social skills with classmates and teachers,” said Dr. Dimitri Christakis, the paper’s senior author.  He is a professor of pediatrics at the University of Washington School of Medicine and practices at Seattle Children's Hospital.