I'm 17, and I've taken part in quite a few younger age oriented roleplays (I play Free Realms, and am a guild leader there). What I find is that, given the opportunity and given exposure, kids of younger ages come to learn the "do's and don'ts" of roleplay and become actually pretty mature people, and most of the time the leaders of the bigger RP guilds are actually the oldest (even if they are not aware that they are the oldest)