A good point, and in fact some modern societies do place the effective age of majority (if not the legal one) that low. I have a friend from Thailand who told me about his frustration with living in the US when he immigrated here at 16 to live with his aunt. Back home, he had moved out of his parent's home at 12 to attend a secondary school in Bangkok and was living on his own as much as any American college student does: still financially and socially tied fairly closely to his parents, but effectively independent. He had his own apartment, bought his own food and cooked his own meals, took care of his own transportation, bought his own clothes, etc.. When he came to the US he felt like he was a prisoner because he went from being an adult to a child in the matter of a single flight.