well, slapping isn't really the meaning. Myth is, that because only whites can blush, only they feel shame, and therefore only they are human. Others would be just closer to animals with their morals for example.
I think one good document about NOISE CULTURE is the dvd "PEOPLE WHO MAKE NOISE". I have seriously watched it twice. It is amazing documentary about certain moment in Portland (US) noise scene. In a way, you simply can worship the extreme goofiness of veterans like SMEGMA, but also I can tell, that if you happen to have any company whatsoever while watching this, simply prepare for stomach muscle aching bursts of laughter. It is not funny all the time, but it is, a lot of time.
There is good stuff there too, but most of all extremely funny. Mostly unintentionally.