It makes sense that people of different ethnicities/countries/etc would have some differences in their art. When you're around people you pick up their ideas and habits and other things. That's why fashion is different throughout all these things too.

yeeeah usually it's very visible whether the art is by asian or non-asian artists. there are differences between jp, kr, and chn artists too, now that i think about it.

Trends, man.

I think it has more to do with the education of an artist than their ethnicity, though there are certainly cultural connotations to any art education.

I think it has a lot to do with how closed many Asian countries are. Culture of west and east part of the glove were developing separately. And even now, in era of globalisation and multicultural exchange on the internet, many Asian countries, such as Japan, prefer visiting Asian sites created in their mother tongue. For example, Japanese usually choose Pixiv over Deviantart. I believe this close environment in which they operate and are inspired is influencing their style a lot.

Yeah, I agree that it's a matter of trends, and artists from the same communities influencing eachother.

Just like a certain cartoonish, lineless style with a crayon-ish brush is currently trending with american artists.

In the german manga scene I see less of a stylistic trend, but apparently the excessive use of white ink for highlights is by far not as common with other artists?