[toomanyrichies]

Genuine question as an American- why would niceness be off-putting? What would you prefer? I'm guessing neutrality or formality, as opposed to outright rudeness... is it because it feels too familiar, and a bit of arms-length distance is more your custom?

Again, genuinely curious as an outsider.

[zkmon]

In most cultures, smiling at someone means, you know them personally. So, when you smile at a stranger, the stranger gets confused. They might think you are crazy. Also it could make them uncomfortable about how to respond. If they smile back, it means they know you, which is not true. Infact, if you smiled at a stranger of opposite gender, it could lead to other complications depending on who are with them, and they could get angry as well.

[AaronAPU]

The phrase “low trust society” comes to mind.

[zkmon]

No. It is lack of reason. Not long ago, if you went for morning jog in a village, you might be stopped and asked - I don't see a dog chasing you, why are you running? Same, if you give away some useful thing for free.

[IncreasePosts]

Some societies think the default position between strangers is seriousness, not niceness. The usual example is Russia if you would like to read more. In Russia, if a stranger smiles at a Russian, stereotypically the Russian would think either the stranger is crazy, or is planning some evilness and is happy about it.