In what way?

there's an obvious correlation between population density and civic honesty (as well as pretty much every other QOL metric)

I have to ask which way, because China and Poland have roughly the same population densities but are on other ends of the scale.

The Asian countries score high on these (Japan isn't listed in the table but would have been high). That sort of makes this conclusion not fact-supported.

Why would that be? And do you have any data about this?

Switzerland is 25% immigrants yet it is also top of the leader board.

Lots of brown ones, evidently: //en.m.wikipedia.org/wiki/Switzerland

I think the issue is that if you create an economically and culturally hostile environment, it prevents assimilation. It doesn't matter what your race, religion etc. is at that point. Recall the state of Irish immigrants in the early U.S., that's where the meme "paddy wagon" results from.