The head bob is a ubiquitous and often mysterious Indian gesture. I have heard it can have many meanings including:
-I don’t know
-Okay – I hear you. Keep going.
-You’re pissing me off, but I’m not ready to fight with you quite yet
-I’m not so sure about that
-That was kind of funny, but not funny enough to actually laugh
Below is a dramatization of events. This is an actor and not a real life situation.