I think that's the kind of a thing that most people know in principle, but which is very hard to actually stick to when you have a raging hissy person in front of you, so it's good to be reminded of it every now and then.
Yes, indeed; that's one big part of it, the tendency to give in to hysterical behavior because it's unpleasant to be subject to it and for a moment you put aside whatever conflict you have with the person in order to get them to calm down; you don't feel that pressure when you're engaged calmly and rationally. That's something that affects people of all levels of intelligence and rationality.
When expressing concerns about the target audience of this message, I was perhaps focusing on the other half of it, the one which is skewed by intelligence/rationality...
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.