FWIW, I asked Claude for its opinion today. It thought that new communication media/dynamics (A7, B14, B15 along with B8 & B9) were likely to blame, and that survivorship bias (A12) probably also plays a role.
Claude also suggested I add “The collapse of shared epistemic authorities” as another hypothesis, similar to but distinct from B15: “It’s not just that gatekeepers died; it’s that there’s no longer any institution or process that a broad majority accepts as capable of settling factual questions. When people disagree about facts, there’s no court of appeal. This makes all disagreement look like stupidity from the other side’s perspective, because there’s no shared standard by which to adjudicate it.”
I was under the impression that emotions affecting people physically is considered very normal and ordinary: anger making the blood rush to your head, fear making you quake or your hair stand on end, shame making you blush, etc. All of those things I consider to be part of the standard vocabulary of emotions such that if I describe someone as <having stereotypical physical reaction> to <associated emotion> I assume the person I’m describing it to will get it most of the time. Indeed, it’s hard for me to distinguish an “emotion” from, say, an “assessment” without there being something akin to physical symptoms going on.