Here's yet another study showing that kids who get smartphones earlier have worse mental health as teens.
So what's the right age for a first smartphone? I'd say its whatever age you want them to cut back on sleeping, reading, exercise, and socializing. I advise not doing that before 14, at the earliest.
Let's make that a new norm, to break out of the collective action trap together. Some parents may then wait even longer. But lets try to get all kids through middle school in the real world, before exposing them to the many harms of adolescence lived on a phone.
Note that this research use the ABCD study, which is the highest quality longitudinal study going.
It confirms an earlier finding by
@sapien_labs that found the same thing
nytimes.com/2025/12/01/well/…