I'm an American, and have never understood why others cheer or clap in movies. There are neighborhoods where loud comments on the movie in progress are not unex

I'm an American, and have never understood why others cheer or clap in movies. There are neighborhoods where loud comments on the movie in progress are not unexpected for discouraged. On the other hand, it was in an upscale movie where the guy behind me wanted to narrate Ed Harris's Jackson Pollock movie--sotto voce, but far from inaudibly.