You're inventing a plausible-but-probably-irrelevant cause when a more likely cause is mentioned in the study: students were not using their phones a lot in school before the ban.

> they did not control for medication or supplements

The only way this would matter would be if phones were banned and then also those other interventions were withheld in order to perfectly counterbalance the expected effect of the phone ban. Do you have some evidence that Iceland suddenly decided to reduce these interventions between 2018 and 2023?

This point isn’t even mentioned in the limitations section of the study, so why are you making it? There are more significant potential limitations to this study that they did describe, including the fact that “we also lacked objective measures of in-school smartphone use and therefore could not determine whether bans reduced actual phone use”. (Though that doesn’t exactly matter either, since if the bans aren’t actually stopping phone use, then they are still ineffective, just in a different way.)

> Alternate interpretation: when it's dark for half the year your mental health isn't dominated by phone access.

This is a nonsensical interpretation that seems to me to betray a lack of understanding of statistics. The planet doesn’t experience any more or less sunlight in the winter between 2016 and 2023, so has no bearing on whether or not there would be a detectable effect from an intervention.

The narrative says that phone use was already banned during classroom instruction in many of the schools that later instituted school-wide bans. The impact on students would've been minimal because realistically the only time they would've been able to use phones beforehand was passing between classes or at lunch/recess.

Though this is still relevant to policy-makers who are thinking of instituting district-wide bans. It's sorta like all the heat around critical race theory: banning something that doesn't actually happen much in schools.

> Improve grades, improve classroom behavior, maybe. What about those?

Isn't that partly the goal with the ban? Fewer distractions.

I actually read it as "They're no more unhappy without than with them" . Kinda occam's razor of if they're not unhappier without their phone, then there's no harm taking it from them.

It's amazing what you manage to not find when you try really hard to not find it.

Reminds me of a scene from the movie "Thank you for smoking" where Big Tobacco's lead scientist has managed to find no link between smoking and cancer for 30 years. It's a miracle!

We do most of our communicating via phones on platforms that encourage flip, nuance-free takes, are hotbeds of disinformation, and so on. Nothing about the environments we exist in foster positive, meaningful communication that collectively benefits us. Everything we used is designed to divide.

Our inability to collectively get along ramped up exponentially as smartphones took off. Phones, and the platforms within that people have become dependent upon, are the root.