At what age does a child become and adult? Do you think there is some magic age when a child should be considered the appropriate age to make inportant educational and medical decisions on their own? And what age should that be? You see at 18 you can join the military and at 48 inches you can ride most adult rides. At 13 you pay adult prices at the most movies theatres yet you can not get into an R rated movie until you are 17. You can drive a car at 17, vote at 18 and drink at 21. Seems confusing , huh? What's you opinion?