Earlier quoted context omitted.
> trigger an immune response, which is not something you generally want to do to your readers In general, you expect readers not live «immune response[s]». It is called "sensation", and you either expect readers to be mature and having learnt to manage it as much as they learnt all other physiological and emotional and intellectual control, or if not mature you want to expose them to the world of serious adulthood fo…
Depending on what you're writing, sensation might well be the entire purpose of the writing. So words that trigger the wrong sensation should absolutely be avoided, and not used to test the reader's maturity or anything like that. However, these sensations are extremely cultural. As a non-American, it's funny to see Americans trying to impose their cultural sensitivities on other countries and cultures. Like criticis…
Ah this is an old internet rumour. Either a) no footage of it survived to be on the internet or b) it was always a rumour.
Here's some discussions respectively from 2015 (trying to find it) and 2000 (stating a slightly different version of it):
https://old.reddit.com/r/AskReddit/comments/2bf9fw/black_peo...
https://everything2.com/user/iain/writeups/Why+I+don%2527t+u...
If you can find a video source of it, I'd be curious to see it.