I'm noticing this among my cousins, at least among social health. I've got one cousin who just entered 7th grade this year, and might be the only person in her class without a phone. One of her best friends just got one at the beginning of the year. Those two are among the only two who actually know how to talk and have a conversation; other kids have no clue how to read tone of voice to tell jokes, or have any clue how to read facial expressions, etc. They honestly say what they want, when they want, without regards to people and then can't interpret that someone is upset.

I've noticed it especially in regards to my 11 year old cousin, who's now had his phone for 3 years. He doesn't pick up on tone in jokes, and so unless the joke has an obvious punch line, he doesn't really get it. He has a lot of one-word conversations, often in a brusque tone, because he just wants to watch Minecraft videos. Often, the first thing he'll do when he gets to my grandmother's from school is go to her bedroom, lock the door, and just watch videos. No interaction whatsoever, and good luck trying to get him to talk.

I also see it to a much more dangerous degree among my high school students. The lengths they will go to to be on their phones during class (and not even to chat; merely to be on them) is, quite frankly, alarming. I fear for our future, and am looking at dumb phones for myself now (I'll keep my dual sim smartphone for when I travel outside the country and exercise because music)