I'm an academic from Europe and routinely tell my PhD students to "be more American" or "write like the Americans" to mean don't be shy exaggerating and presenting their work like much more important than it really is (or perceive it to be).

Because indeed, the American academic culture is full of BS (perhaps the most glaring example being that the cornerstore of hiring is the recommendation letter, which to me is essentially overt nepotism - and in a recommendation letter, every candidate is the best ever, Gauss incarnate, the Chosen One to break the frontiers of knowledge, because if you say even the slightest bad or ambiguous think they're not going to get hired. But everything is like that).

The thing is that in academia everything is competitive (grants, conference acceptances, etc.) so we Europeans must be Americans as well if we want to be successful, because it's hard for a paper, proposal, etc. to get chosen if you're being realistic while some of your rivals are exaggerating everything. This is something I realized when I worked in the UK (not America, of course, but more "American" than the rest of Europe) and then even more when I worked with actual Americans, and I consider this realization to have boosted my career considerably.