It's not exactly what the article is talking about but: I have a 2 year old niece. Her family have an attitude of "let her learn for herself" that I've found pretty interesting. They keep a very close eye on her and try to warn her verbally and with demonstrations but don't really stop her from doing anything.

So instead of physically separating her from a hot kettle they just go "it's very hot!" and demonstrate by touching it carefully and then pulling their hand away. They let her play with matches.

She could pick up on these cues long before she could understand words. But it does look exhausting. And there have been some moments (once she was trotting around holding scissors pointing up in the air) where I've thought "no that's too risky and no amount of careful supervision can prevent injury here". She has also burned herself, but only once.

So overall I am pretty impressed, at least in principle, and if I have kids I'll definitely endeavour to try and curb my overprotective instincts.