[csa]

As someone who has lived in Japan and China, I can say that I have seen this happen.

I have also seen a similar phenomenon at Ivies (at the undergrad level) if you exclude the athletes, so it’s not even a race or national culture thing.

Imho, the short answer is that it is the way a large portion of that sub-population is raised - lots of study, very limited socialization (esp. wrt the males), very few positive male role models who are like them in home life or in popular culture.