The attention audit
What scientists disagree about
One view. Some researchers, such as Jonathan Haidt and Jean Twenge, argue that the spread of smartphones and social media around 2012 is a major cause of the rise in teen anxiety and depression since then, and call for later phones and phone-free schools.
Another view. Others, such as Candice Odgers, Amy Orben and Andrew Przybylski, point out that in large studies the average link between screen time and wellbeing is small, that the studies mostly cannot show cause and effect, and that other changes happened at the same time. They argue for focusing on specific harms and on the teens who are hit hardest.
What both sides agree on. Sleep matters, so a phone that keeps you up at night is a problem. Heavy use that crowds out sleep, exercise and time with people is worth watching, and the kind of use matters, not only the total.