I think it is high level of "human capital" plus an understanding that your society is a cooperative venture. I am not sure, but I would hazard that most Japanese are highly literate, brought up to behave well, and that there is actually a social contract in force. I am willing to bet just a little bit of money that your average high school grad (i.e. "working class") Japanese person would rival our state college educated class for both high levels of good behavior and knowledge. I bet there would be similar behavior in the Scandinavian countries.

And, interestingly, everyone would expect the students at a state college or better to behave just like the Japanese.

Really, the fact that there is such widespread poverty, thuggery, and low educational levels in the US is just plain embarrassing. That you can't trust the people you live around is the weird thing, not that you can.