Probably too late to see this, but I (and my teachers) think of "culture" as basically "training". So if you can get a lot of great character training without ever being exposed to, say, Mozart, you would still be in my "high human capital" bin. In the US, I think usually character and education are correlated, mainly because being of high character opens up educational avenues for you (for which it is economical rational to pursue), while being a punk-ass closes off these doors.

There are lots of exceptions, of course; rural areas might be a case (I am rather fond of so called rednecks myself).

Also, I said that high school grads probably had the training of a mediocre college grad in the US -- I didnt say anything about high years of education in Japan being the cause of good behavior.