After teaching English in both the Korean and the Japanese public school systems for years, I honestly have no idea where these stereotypes come from. The kids in this part of the world don't have as many bad influences outside of the classroom and they do spend a lot more time with their heads in the books but they're equally as zany, off the wall and out of control as their Western counterparts. They still skip class, smoke and get into all sorts of other trouble outside school, especially here in Westernized Japan where the precursors to gang/swarming behaviour are already taking route. The main difference between the UK, Canada and Korea is that kids spend so much time studying and are under so much more pressure to perform on academic tests that they really don't have time to be silly.