The invention of Childhood

"Nothing wrong with that except that children are essentially not in this category and we would not attempt to treat them as such otherwise the prisons might be further crowded and there would a lot more empty schools."

Funny. Many historians don't see that civilization was a failure back when Men and Women of 17 were expected to be well along their paths as productive adult members of society. It was a sign of poor character if an adult refused to accept responsibility, refused to accept a job, refused to participate. There might be some extended circumstances for those who were well along the path whose acknowledged duties to society ( say a military career ) precluded some other aspect, ( such as marriage for a cadet. ) But on the whole, the present life of a 17 year old child would have been deemed ruinous of his or her character and ability to act as a citizen.

The substance of 17 year old hasn't changed. We've just invented them as children.

How about 15? Or 12? Or 9?

There's nothing wrong with recognizing incapacity where it exists. There's everything wrong with presuming it. And once presumed, not only will the confirmation always be found, but the conditions to breed more incapables will be created.

"No less happy"

Much of what passes for juvenile rebellion and anger ( enough that its assumed that being antisocial is a necessary phase for teens to go through ) is what you see in any adult who is incarcerated or enslaved. Being antisocial is not a necessary consequence of being a child, but it is the obvious outcome of treating a person as if they were not a person.

Dante