> I also feel like the hedonic adaptation hypothesis leads to this kind of absurd conclusion that people are unaffected by anything regardless of severity. That is, it doesn't matter what we do to others because it's their fault how happy they are.
I wouldn't say that this is an absurd conclusion, as long as you divorce "is happy" (as in, "frequently experiences happiness-qualia") from "has utility" or "is functional" or basically any other measure of QALYs.
Pretend that instead of talking about "happiness", we were talking about "sneezing." It'd make sense that how often you sneeze isn't a reflection of your long-term emotional state, right?
Well, why would you expect "how often you smile" or "how often you experience qualia of contentment" to be a reflection of your long-term emotional state? What privileges those physiological facts as telling you something about yourself, over the fact of how often you sneeze?
Consider: people cry while watching sad movies. This is an short-term emotional state evoked by the movie. It doesn't outlast the movie. Would you expect someone who experiences more movie-cry-sessions to have a lower long-term emotional state/utility?
> So you see recurring time series patterns with, e.g., Christmas because the positive language is part of what is socially entrained, even though it's disconnected from changes in your mood.
You suppose here that mood is a fact about our internal experience, rather than a fact about our linguistic rationalizing self-narrative of that experience.
If the "me" that tells you that there's an invisible dragon in my garage, and the "me" that goes into my garage anyway because I don't expect to get eaten, are essentially different people (one living in a land of social narrative; one living in a land of causal prediction and goal-directed action) which one of those selves would you expect to have a "mood"?
(It's not a trick question; I'm not really sure either. But it's worth pondering, I think!)