I have been familiar with the Indian headshake or “wobble” for many years and so much that whenever I go to India, I actually start doing it. It is contagious and useful. I even keep doing it for a bit back in the Western world after returning from my travels in India.
For those not familiar with it, it might even be a bit hard to do the headshake naturally. I have a friend who was trying and he just looked awkward and silly.
I think that the headshake is a big characteristic of the Indian culture and communication, though some say that it is more common in the South of India than in the North.
“The film presents an array of headshakes and shows how subtle variations in velocity, vigour, and amplitude of wobble denote different meanings, including: “yes”, “no”, “maybe”, “what’s up?” and “carry on”. Mathew admits that his headshakes have been somewhat exaggerated for comic effect, but maintains that it’s a true picture of a national trait. ” (BBC)