There are always traditional markers for growing up in every culture. Ithink some of the most iwportant ones in American culture are things like being able to vote or drink alcohol. Or it could be when you get a real job or when you move out from living with your parents.
I think that society defines adulthood with things like age (usually 18 or 21.) I think age isn't really that important in growing up, it really depends on the person. Some people have to grow up earlier so they can help support their family just so they can eat a good amount of food. Other people live in better situations and they don't have to grow up as fast.
It sounds strange when you hear about people growing up in other cultures. You hear about people working, driving , and even going into the army when they're our age. Like I said before I don't think age shoulb be such a landmark for growing up because it will always be different for everyone. Everyone is in a edifferent situation and I think that this is an important part of how soon people wil grow up.