Earlier quoted context omitted.
It's shocking to read opinions that kids would not «have that level of self-control». Children can display self-control... And of course they can. (Just a tiny example: in many countries, we have them study since the age of five, sometimes earlier. They already have a sufficiently working anterior cingulate gyrus at and before that age; they have understanding of tradeoffs at and before that age.) -- Ooooh, hitters t…
Does that explain why most societies don't permit children to drive cars? Perhaps that's not based on development, but just being too short? I kid, but clearly we don't let children drive, vote, drink alcohol, have sex etc. because of general observations about their limits, including self-control.
We don't let children damage themselves because it is plain indefensible. If they want to, they must have passed said formal threshold.
These are not matters of self control.