> Just going full Amish on them until they’re 18? 25?

Seriously false dichotomy. You understand that you can access FB/IG from a computer, right? You don't need a smartphone to do that. Could be a desktop, with shared accounts for multiple userd. And if you do have a smartphone, you can turn it off at night, or put it on the table.

And you can use social media without taking and posting selfies. Or at least, doing so excessively.

> Look at all the Baby Boomers and older Gen X’ers that got on the Internet in the past ten years and instantly had their brains rotted despite decades of life experience. Should there be some kind of emotional intelligence ...

But that's only the highly visibly subset of them who don't resist social-validation, confirmation bias, mindlessly forwarding viral crap, slurs and gossip. The other X% that behave reasonably and refrain from 24/7 ideological foodfights, we don't notice. Certainly, the big social media with quantified vote-counts, followers, shares, and in the absence of fact-checking, are incentivizing the death of civil discourse based on, uhh, facts.

It's pretty obvious one of the main necessary habits is skepticism: inquiring for the precise source and attribution of claims, checking facts, scrutinizing your own susceptibility to want to believe a specific claim (or source) without objective proof. And by extension, picking the group of people you associate with online to be like that.

Haidt also documents how socialization and playing among children [in the US] has stopped being face-to-face and moved online within that decade. This is something that can be reversed at ages 8, 12, 14 etc. Coordinated action by schools, classes and parent groups would be great.

> there’s no truly safe age to start using social media as it currently exists.

*Only as it currently exists post-2016, not as it used to be pre-2012*, which is the exact point Haidt repeatedly hammers home. People didn't complain about MySpace, Friendster, et al: why? The culprits Haidt mentions in passing: making counts of likes, upvotes, followers visible (let alone prominently showing them like as if they're the defining thing), and the (artificial) pressure to constantly post (selfie image) content that juices them, and to compare to other people's. Also, (for adults) retweeting other people arguing. We (= US Congress) can easily mandate switching FB/IG back to a 2012 interface. (Of course, they'd lose lots of advertisers and users, boo-hoo. Push the financial incentive to them to suggest solutions.)

Consider also how widely US COPPA law [0] is flouted in allowing under-18s or under-13s to register a profile and self-certify a fake age over 13 or 18: imagine if that had to proven in person with ID, just like buying alcohol or tobacco, or driving, or buying a gun. But can anyone remember a criminal prosecution of either a parent, or a social network which knew or had reasonable knowledge that one of its users was under-13? Where is basic enforcement? COPPA doesn't appear to have criminal penalties.
Why shouldn't COPPA have criminal penalties, on both the parent and the social-media company (gasp)? (in conjunction with mandating changes to remove the pressure for likes, upvotes, followers).
Or, less drastically, social-media can monitor its individual users' use patterns and suggest them when that becomes unhealthy or excessive ("You've been looking at influencers for the last 4 hours. Time to disconnect and do something else?").

[0]: https://en.wikipedia.org/wiki/Children%27s_Online_Privacy_Pr...