Its a pity the data is so out of date in the article. Remember, things start, but they also stop. Sounds dumb but in context its insightful. Lets take the hy

Its a pity the data is so out of date in the article. Remember, things start, but they also stop. Sounds dumb but in context its insightful. Lets take the hypothesis as true that as as smart phone use goes up 10% per year, the "Z" measure goes up 0.5. Whatever a "Z" is? Regardless, cell phone use started going up coincidentally at the same time Z started going up. Thus is astrology proven. No wait seriously the point is cell phone use can only go up to near 100% one time. So what happened to the annual 0.5 increase in "Z" after cell phone use topped out at 80% or 90% or 100% or so? Sorry, no data provided. Another interesting idea: There's a deeper level to phone or social media use. Perhaps its Facebook. I know my kids generation has pretty much abandoned FB, so if its a FB specific problem it should reflect in "Z" levels. Or online dating. Or onlyfans as a job market. Another interesting idea long the lines of astrology where coincidences prove cause and effect: Peak legacy style TV viewing hours per day was around 2010. Perhaps enormous amounts of professionally produced propaganda had a sedative effect on teens, or professionally produced propaganda in TV form is more effective than social media form.