One other possible explanation is that phones are everywhere, regardless of most any other factor. Take any teenager, anywhere, in any walk of life, age, or social group, nation, etc. They very, very probably have a phone. Guess what’s also mostly everywhere, regardless of other factors?

None of these are perfect explanations, obviously, but I’ve seen what phones do to my kids (even in the limited amount of time they have) and others. It’s absurd to ignore it. Sure, I can’t prove that phones are the cause, but my son goes from the sweetest kid to an anxious, angry mess as soon as he has a phone in his hands (and before you ask, yes, sometimes it’s inevitable, I live in a capitalist society that expects me to both work my ass off and to take care of my kids at the same time. Also, I don’t have the illusion that I can stop him from ever using one, so I’d better be around and teach him how to deal with it the best way possible).