It was from an episode of QI. Here's the clip if anyone is interested: https://youtu.be/E9PSg0sQyfs
My observation was that when you go into a shop in SF, you'll get greeted to a lesser degree, but more cheerfully.
In Berlin, you were greeted almost every single time, but more perfunctorily.
In that regard, I preferred the Berlin approach, even though it required me to respond more often. But I could simple acknowledge the greeting and keep going. It was more intrusive, but less demanding.
This (and the studies in the OP) should be taken with a grain of salt; there is a replication crisis in science, and psychology is one of the worst-affected fields.
https://en.wikipedia.org/wiki/Replication_crisis#In_psycholo...
In some attempts at replication less than 50% of studies were reproducible, indicating that they were either p-hacked or simply badly designed. Priming results seem to be particularly flimsy.
I had culture shock going to stores in the rural areas, because the friendly customer service attitude appeared to be much less fake. People didn't feel as rushed. They took a little extra time to have genuine communication. It drove me crazy, because I was accustomed to the efficiency of city retail, but I've come to appreciate it.
It is a cultural shift though that seems alien initially, but then you really get used to it, and it really does make people feel better when they encounter it literally at every store. Positivity also disarms people and makes them more likely to purchase goods.