I don't think this expectation is a consequence of race or ethnicity, but a consequence of seeing it work in one's own local society. (Privilege, in a generic sense of socio-economic status, probably does play into that. It's easier to have high trust when nobody is desperate.)
Indeed it's not a question of race and ethnicity per se, but it's also true that historically such communities that demonstrate a bit of a privileged mindset are mostly white (with some rich Asians here and there).
Privilege stems from community as you alluded to. Many people's worst problem was to ask a new neighbor to turn down the music 1-2 times until they learned to be a good citizen of the neighborhood and that was that. Some of us however had to deal with much worse situations -- on a regular basis -- and for people like myself I really find it difficult to sympathize with OP because coldly and mathematically speaking, they simply did not cover their bases, and they had signs and signals that they should have done it.
