Have you wondered if the subtle and not so subtle differences in the way people, say from India and USA, conduct themselves? Differences in facial expressions, walking, use of emoticons in writing...
I have wondered often. Cultural influences contribute to many of our physical expressions and the way we perceive expressions that other wear. Indians would shake their heads from side to side in agreement and invite you to do the neck dance with them. Italians would build spires with their hands (the Duomo's influence, surely). And, American emoticons would cause Japanese ones to wrinkle their brows and bow repeatedly.
Read Cognitive Daly for a nifty note on emoticons and how they differ between people in US and Japan.
The neck dance? Do elaborate.