I think I actually failed to respond properly in this comment. You were talking about smartphone use while the article was talking about social media use. I thi

I think I actually failed to respond properly in this comment. You were talking about smartphone use while the article was talking about social media use. I think Haidt and implicitly both of us were conflating the two, but they are separate topics. I did a search for the effects of smartphones, trying to avoid meta-analysis describing only "overuse", and [0] came up. This seems to indicate somewhat larger effects of smartphones on anxiety. I can't access the article easily right now, but from the titles of other studies, it seems like sleep disruption might be a factor. [0]: https://onlinelibrary.wiley.com/doi/abs/10.1002/smi.2805 https://onlinelibrary.wiley.com/doi/abs/10.1002/smi.2805