Largely matches my experiences as a long-term visitor to the US. Particular points that made me nod my head:
But the rejoinder "you're welcome", which once greeted almost any expression of thanks in America, is in retreat.
In its place is a sort of wordless acknowledgement, halfway between a grunt and a hum, "mm-hmmm". It is a sound that acknowledges your thanks but implies that no great joy has been found in helping you either.
I'd almost forgotten about this, but on my first day in the US I thanked a hotel clerk for some service and got an "mmm-hmm" acknowledgement and it felt incredibly rude. I suppose I don't even notice it any more.
For some reason, I always thought this phenomenon was imported from Europe. I lived in a European tourist mecca for a few years, and whenever I would thank a European for something, they wouldn't say "you're welcome" or even an "mm-hmm". Usually they just smiled and nodded.
I can see how it might appear a little brusque though. Americans, particularly here out west, tend to put on an air of stoicism, so our "mm-hmm" probably comes without a smile or even a glance in your direction. But I've interpreted that to mean that I am being helped as a matter of course, not for the sake of propriety or some sense of obligation.
But the rejoinder "you're welcome", which once greeted almost any expression of thanks in America, is in retreat. In its place is a sort of wordless acknowledgement, halfway between a grunt and a hum, "mm-hmmm". It is a sound that acknowledges your thanks but implies that no great joy has been found in helping you either.
I'd almost forgotten about this, but on my first day in the US I thanked a hotel clerk for some service and got an "mmm-hmm" acknowledgement and it felt incredibly rude. I suppose I don't even notice it any more.