What research says about screens and kids, in plain language.

Japanese researchers analyzed the US Adolescent Brain Cognitive Development study, which enrolled 11,878 children at ages 9 and 10. They used data from 10,116 children at the start and 7,880 two years later. Children reported their screen time across TV, video games, and other devices. Parents rated ADHD-related symptoms, and teachers added ratings for a smaller group. Longer screen time predicted more ADHD symptoms two years later, even after accounting for how severe symptoms were at the start. Heavier screen users also showed subtle differences in brain structure that partly accounted for the link.

Researchers at Children's Hospital of Philadelphia analyzed 10,588 children in the national ABCD study. At age 12, children who owned a smartphone had higher odds of depression (1.31 times), obesity (1.40 times), and insufficient sleep (1.62 times) than those who didn't. Each year earlier a child got a phone was linked to about 10% higher odds of obesity and short sleep, though not of depression. Among 12-year-olds without a phone, those who got one in the next year had higher odds of clinical-level mental health problems and insufficient sleep at 13 than peers who still had none, even accounting for the prior year. Results held after adjusting for demographics, income, other devices, puberty, and parental monitoring.

Researchers pooled every study they could find that compared college students taking lecture notes by hand versus typing them. Students who took and reviewed handwritten notes scored higher on tests (effect size about 0.25). Typing produced much longer notes (effect size about 0.92), yet those extra words did not translate into better learning. The authors estimate handwritten notes would be expected to produce higher course grades, and conclude they are more useful for studying and remembering material.

UNESCO's 2023 global report concluded there is little robust evidence of digital technology's added value in education. Products change every 36 months on average, faster than they can be studied. Only 7% of UK ed tech companies had run randomized trials, and in a survey across 17 US states, only 11% of teachers and administrators asked for peer-reviewed evidence before adopting a product. Only 16% of countries guarantee student data privacy in education by law. The report says technology should complement, never replace, face-to-face teaching. It also credits accessible technology with opening doors for learners with disabilities.

This Japanese study followed 7,097 mother-child pairs. Parents reported screen time at age 1 in four groups, from under 1 hour to 4 or more hours a day. Development was then assessed at ages 2 and 4. More screen time at age 1 was linked to higher rates of delay in communication and problem solving, with risk rising step by step as screen time increased. At age 4, children with 4 or more hours a day at age 1 had nearly twice the odds of a problem-solving delay. Personal and social skills did not show the same pattern.

In 2023, the Surgeon General issued a formal advisory, a statement reserved for urgent public health issues. Up to 95% of teens ages 13 to 17 use social media, and more than a third say they use it almost constantly. Teens who spend more than three hours a day on social media face double the risk of depression and anxiety symptoms, while the average teen spends 3.5 hours a day. Nearly 1 in 3 teens report using screens until midnight or later. The advisory also notes benefits: 58% of teens say social media helps them feel more accepted, and 80% say it helps them stay connected to friends.

Facebook launched at Harvard in 2004 and spread to other colleges in stages before opening to the public in 2006. Researchers compared student mental health before and after Facebook arrived at each campus, using about 430,000 responses to a national college health survey. Facebook's arrival worsened student mental health, including a 7% increase in severe depression, and made students more likely to report that poor mental health hurt their schoolwork. The longer students had Facebook, the worse the effects. Evidence pointed to unfavorable social comparisons as the main reason.

Researchers at Norway's University of Stavanger pooled experiments comparing children ages 1 to 8 learning from the same story on paper or on screen. When a digital book was simply a digitized copy of the paper book, children understood the story less well on screen. Reading print books with an adult who talked with them was more effective than children using enhanced digital books on their own. Digital books did outperform print when their enhancements, such as animations, closely matched the story. Built-in dictionaries helped vocabulary but did nothing for, or hurt, story comprehension.

Gaming disorder is now a recognized diagnosis in the World Health Organization's disease classification. This meta-analysis pooled prevalence studies from 2009 to 2019. Worldwide, about 3.05% of people studied met criteria, falling to 1.96% in the studies with the most rigorous sampling. Rates were about 2.5 times higher in males than in females, and adolescent samples showed higher prevalence. Which screening questionnaire a study used explained most of the variation between studies.

Across 59 reports and 122 independent effects involving children ages 0 to 6, learning was lower from video than from face-to-face presentations by about half a standard deviation on average. The difference decreased with age and varied by learning task. Live versus prerecorded video did not explain the difference across studies. The authors identified study-quality and publication-bias concerns.

This review pooled studies of children 12 and under that measured both screen use and language skills. More hours of screen use and more background TV were linked to weaker language. Two things were linked to stronger language: educational programs and co-viewing, where a parent watches along and talks about it. Children who started using screens later also had stronger language skills.

Researchers from J-PAL, MIT's poverty and policy research center, reviewed only the most rigorous studies of education technology, mostly from developed countries. They grouped them into four categories: access to devices and internet, learning software, text-message nudges, and online courses. Programs that supplied computers and internet alone generally did not improve K-12 grades and test scores, and in some cases hurt achievement, though they did improve computer skills. Learning software built to help students practice specific skills at their own level showed real promise, especially in math. In four of six studies that directly compared online and in-person courses, students did worse online.