> Academic achievement (n= 2,020) was obtained from administrative records providing the end-of-grade standardized test scores for reading and math for the 2014–2015 school year.
> School belonging (n= 2,104) was assessed with the six-item Psychological Sense of School Membership23 self-report scale of school membership (e.g., I feel like a real part of my school; People at my school are friendly to me; [0] Not at all true to [5] very true), α= 0.84.
> Conduct problems (n= 2,103) were assessed using the 26-item Problem Behavior Frequency Scale24 of behavioral aggression and violence in the last 30 days (e.g., In the last 30 days, how many times have you …skipped school; stolen something from another student; [0] Never, [1] 1–2 times, [2] 3–5 times, [3] 6–9 times, [4] 10–19 times, and [5] 20+ times). This scale was converted into a count of reported problems (binary for each item rated >1 then summed).
> Psychological distress (n=2,104) was assessed using the six-item Kessler Psychological Distress Scale25 to measure the frequency of participants’ feelings of distress over the past month (e.g., During the past 30 days… about how often did you feel worthless; about how often did feel restless or fidgety? [0] None of the time to [4] all of the time), α= 0.66.
> General physical health (n= 2,097) was assessed with an item from the Add Health General Health and Diet survey26 (i.e., In general, how is your health? [0] Poor to [4] excellent).
I find it not surprising that having a social media account is not statistically related to the results of these measurements. And I suspect for example, being exposed to online sexual contents will also not affect as well. When talking about these things, I tend to be skeptical of behaviorism and feel like a more nuanced methodology should be taken.