We shouldn't confuse observation with cause. If the OP genuinely observed such changes in behavior, then that's different than ascribing a direct cause to scre

We shouldn't confuse observation with cause. If the OP genuinely observed such changes in behavior, then that's different than ascribing a direct cause to screen time. Perhaps some children respond differently. Perhaps other factors play out by means of screen time. Perhaps what their kids are doing on their phones is different (we shouldn't forget the affect of the content on the screen). Who knows, and from a parenting point of view, it may not matter all that much when deciding what to do. If reducing screen time improves symptoms, then that's a good start, at least.