I'm 14, and I'd have to say 13-16. There seem to be quite a lot 'youngsters' but not people who are so young they act ignorantly and don't spell correctly etc., without knowing it. However everyone who's posted in this thread seems to be 18+, so perhaps my theory goes out the window.
Where are all these people who seem to be between 10 and 12? Perhaps they are in General, a place i dotn often go but a lot of members call everyone but themselves immature. I sometimes wonder if we arent all 11, it certainly seems that was by what people are saying about others.