There are linguists who quantify and measure this, of whom the most prominent is Deborah Tannen:

http://www.deborahtannen.com/scholarly-articles

("Prominent" here meaning "writes popular books as well as academic ones".)

One of the things that jumps out is that "culture X" is rarely as broad as an entire country (except perhaps a microscopic one). There are always cultures within the country, defined by gender, age, religion, wealth, location, ethnic heritage, etc etc etc.

There genuinely are cultural groups who will speak less directly ("Would you mind passing the salt?") and those who will speak more directly ("Pass the salt.") It's not just more-and-less; you still have to hit the correct level for the specific instance.

Tannen is perhaps most famous for writing about the different styles that men and women use (in different groups; it's very much taught by culture, not biology). I found it immensely helpful for understanding not just what women say but also what I say. I highly recommend her books.

I'm sorry I don't have direct links to scholarly articles that provide exactly what you're looking for, but that's where I'd start looking for them. It's entirely possible that they exist -- but they almost certainly don't come down to "The Dutch are more direct."

This isn't a pissing contest, it's simply the social standard here which sometimes accidentally leaks out to people who do not appreciate it, or wrongly interpret it as rudeness.

For us as practitioners of this behaviour, intended rudeness is actually easy enough to spot.

The point is that there are many cultures of which people claim "they are so direct". I've heard it said about Bangladeshis and Israelis too.

It may be true. A significant part of the world may be outside the "always lie to avoid offense" way of conducing yourself.

I would also say that "being direct" and "saying difficult things" are often not be the same. The former may just be "saying whatever pops into your head" whereas the latter is much more carefully considered.

> This isn't a pissing contest, it's simply the social standard here which sometimes accidentally leaks out to people who do not appreciate it, or wrongly interpret it as rudeness.

Well, as in any other country: there exists rude people in The Netherlands as well ;)

So, the next time when someone says "Oh boy, I talked to this Dutch... he was rude!", what are the chances of that Dutch being a) straightforward, b) rude, or c) both?. I find c) happens most of the time.

Oh yes plenty of rudeness to go around here. And I get what you mean, there's a perfect example in one of the other comments[1] of what can happen when the true intent is unclear.

Although not always easy, not letting yourself feel offended, assuming positive intent, and just walking away with a smile is a guaranteed win under most circumstances.

[1] https://news.ycombinator.com/item?id=27190514

The book The Culture Map goes through that and lot of other "Culture X is more Y than Z" in a readable level of detail.

Are you sure you were in the proper position to define rude, mature, or productive? I don't mean this as a diss but those are all defined by either implicit or explicit standards or goals.