[forferdet]

I think it's because of the cows! In India, the cows roam around freely, and if you have ever been on the road with a cow in front of you, it does not give a shit and will basically just stand there, eventually move when it feels like it. The obvious action to alert something/someone hindering you is to use the horn, "you are in my way", but that does not work for cows that well.

Over time, this weird culture developed of honking. Often honking in reply to each other, like a rhythm almost.