I don't know whether this really counts as "body language," but that reminds me of something my brother noted when he went to New Delhi with his wife. In India (and various other countries, at least in Asia), there's this practice of charging foreigners a lot more than local people. In order to avoid being charged "foreigner's price" while visiting the Red Fort, my brother and sister-in-law tried to pretend to be Indian by randomly jabbering in their respective languages while standing in "line" to get tickets (I think). However, people could easily tell they weren't from India because they were too polite
; they were just patiently standing there. If they were from India, they would've been pushing and shoving.
Anyway, Indian body language. There's the well-known one with the wobbly head (in fact, I believe there's a whole YouTube video on how to use that particularly body language effectively in an Indian context). And the (probably even better known) hand-folding and bowing thing, but I'm trying to think of other ones.
Well, here are two things I just thought of:
1. It seems that if you cry in public among Indians without any prior explanation, they will often assume that someone died (or else something similarly horrible must have happened) and cry with you.
2. Among scientifically oriented Indian men (mostly engineers), I've noticed this habit of putting their hand in a certain position while trying to make a point during a conversation, and then keeping
it there, frozen in that position, for at least two minutes (sometimes as long as five) even though the conversation has already moved on from the aforementioned point. IIRC, when I asked my dad about it, he claimed that the purpose of this was to establish/maintain the point that was raised.
One more thing that I think may be specific to (fairly conservative) Malayalees: If two or more people who are considerably older than you are having a conversation, you are allowed to listen but not to participate unless one (or more) of those people asks you to.