Adult has always been defined depending on age for hundreds of years, 200 years ago you were an adult at 12 or 13, now its 18 or 21 depending on what country or culture you come from. Back hundreds of years ago, childhood was never really seen as a different part of life, the sooner you got down the mines and started working the better. Childhood has always been a social construction. Adult is merely the age that society tells you, you must take more responsibility. To me, being a kid/adult has nothing to do with age, its to do with how you feel in yourself, im almost 18 (infact 18 next month) and i feel nothing like an adult. So in my view even when im 18 (which is when my country tells me im an adult) i still wont be an adult, because i do not see myself as an adult. Catch my drift? Its not like when you turn 18 you're magically more mature and sensible and more responsible, its not a magic day that transforms you into an adult.