> Compare that to boys who are supposed to be raised as more independent and tough. Is it possible that the way we raise boys versus girls is what's causing more boys to have trouble paying attention? Self control, willpower, and the ability to pay attention are all non-cognitive skills. If "attachment" and "dependency" are the things that develop a child's non-cognitive skills… could this be why more boys have ADHD than girls?

No, please read some research, please, for the love of god please stop, no. This conjecture is thoroughly questionable, there is copious research to show these traits developing essentially from birth. The same behavioural differences exist in effectively the same way cross-culturally (including in Japan).

There's more to it, schools in japan place a lot of responsibility on the kids. They are responsible for maintenance of the school (the non-dangerous kind), and later somewhat responsible for governing aspects of the school, among other things.

I can't remember a time in a Canadian public school where I was asked to do something useful for somebody. I think more of that would have helped a lot in terms of motivation.