Adjective order in academia: "Italian young adults" It's always been my understanding that age precedes nationality in standard adjective order (see, for example, The Royal Order of Adjectives); thus, it should be "young Italian adults" rather than "Italian young adults". 

However, I'm revising a demographic study and decided to double check this by searching Google Scholar. To my surprise, I found 539 uses of the latter vs. 217 of the former. Regular Google delivers 88,700(!) vs. 1830, and I get similar results with various nationalities and also from Google Books (though not from the news).

I don't think such a large discrepancy could be ascribed to overall misuse, and the "incorrect" order occurs mostly in academic texts. So, my questions:


Is there some reason why the order of age and origin adjectives
should be reversed in academic (specifically demographic) texts? 
Is that really the standard?
I speak English only as a second language, and I don't do research that involves young adults, but my guess is that it's because "young adults" is a fixed expression that is very close to a compound word. So it feels weird to split it with an adjective. This would be a good question for English.SE, but I think that we are in the middle of a linguistic process where this expression is transitioning to become a true compound word.

Anyway, it is a common saying that "the international language of academia is broken English", so you shouldn't take academic texts as an example of style. For most academic writers English is a second (or third, fourth...) language, and many write by translating word-by-word constructs from their native language. It shouldn't be surprising to find the wrong word order.