I think interruption comes in at least two modalities: 1. To stop the flow of conversation. This is definitely rude. A manager shutting you down, for example

I think interruption comes in at least two modalities: 1. To stop the flow of conversation. This is definitely rude. A manager shutting you down, for example. 2. To facilitate the faster flow of conversation. This is The Church of Interruption; the point of the interrupt is to move the conversation to the next point with less waste. Some folks when they are speaking perceive these as one and the same, but they are actually quite different. In fact, to one who aligns with The Church of Interruption, drawing out a talking point feels rude -- as if the conversation partner were giving a speech and the rest of us are merely here to listen. My wife is Caucasian (Polish/Italian) and I'm Asian (Taiwanese) and definitely both of us fall into the latter. I think the high density of Italian, Indian, and Asian immigrants here in NY/NJ might have something to do with it as well!