Why do Indians nod the way they do?

I was in LA for the weekend, visiting people at USC. Now because USC is not in a very safe area, they have this thing where you can call up a cruiser and someone will drop you home or some place, for no cost. I was with a friend and we called the cruiser cos we didn't want to walk. As soon as we get into the car, the person who was driving said she wanted to ask something about Indian culture. She wanted to know why Indians nod the way they do - in practically every direction! She said that Americans nod from up to down for a 'yes', and left to right for a 'no'. I was laughing in my insides! Yet another American confused with our nods! The reason she asked this was because, before I got into the car, someone had nodded at me (the Indian way) and I had understood the nod!

   To me this was a refreshingly honest question - probably the first of its kind in America! When she said Indians nodded this way so that Americans wouldn't understand them I was in splits :) She was joking, of course. So me and my friend, we tried telling her how to decipher the nod, you know, look at the face, and not the direction. And then I decided it was my turn! I asked her if Americans actually meant it when they say "how are you doing" or some other similar phrase. She said, "Almost never", confirming my hypothesis. This was something that had puzzled me for ages, lol.

I remember reading about Americans' confused interpretations of the Indian nod sometime back. I believe its more common now because of the IT industry and all the junta flocking here. But does anyone have any idea why us Indians nod the way we do? I for one don't!

As I expected, people have blogged about this too. This is an interesting post and here is a forum where people actually discuss how to master the nod!