A couple of questions/observations as someone born in the UK who emigrated to the US at 25. 1. I wonder when this "difference between culture-driven emotions"

A couple of questions/observations as someone born in the UK who emigrated to the US at 25. 1. I wonder when this "difference between culture-driven emotions" fades away. I've been in the US for 35 years now, and I still sometimes sense that I'm viewing interactions the way a British person would (less often than I used to) 2. I wonder how the "noise" of differences between individuals compares in "amplitude" to the ability of culture to shape emotion. Any given population of any significant size will likely contain fairly wide variations of introversion, sociability, communication comfort, positivity, etc. etc. To what extent does or can cultural factors create any sort of coherent pattern "on top" of that variation? 3. Some US habits can be seen as having nothing to do with the relationships between individuals, and everything to do with creating certain social moods. The reason that US retail interactions are studded with "Have a nice day" is not, in general, because anyone actually cares that much about whether your day is nice or not, but because having people behaving in that way creates an easy going, affable mood in which people's anger, disappointment and sadness of the moment is not really appropriate to bring to the surface. It can seem grating and "fake" on early encounters with it, but after a while (maybe a long while), you can appreciate it as a communal, non-coercive effort to "make nice" because everyone benefits from that, on average and over time. 4. US English really needs to re-acquaint (no pun intend) itself with the word "acquaintance" as an alternative to "friend". The almost universal use of "friend" to describe anyone you know (even from the most singular and minor of interactions) really robs verbal behavior about the social environment here of so much subtlety.