A separate comment so you can downvote this one. Have you ever written about the link between HSP and autism? I couldn't find this topic using the search box. And how is it going with scientific recognition of high sensitivity as a personality trait?
I have mixed feelings about the HSP concept, because it filled a gap at a time when autism was underdiagnosed. I feel betrayed by doctors who claimed that autists didn't feel empathy - because I felt too much to do anything useful with it. Nothing made me understand myself better than diagnosing myself as autistic. There are more traits and correlations I recognized than just the diagnostic criteria, from IBS to indifference about certain gender norms.
I read your post differentiating HSP from introversion, shyness and social anxiety. I could write pretty much the same about autism. The medical community moved towards defining one autistic spectrum, where Asperger's isn't seen as a separate condition anymore. High sensitivity could be one end of the spectrum then. I would explain the many different symptoms of autism as unconscious coping strategies for dealing with overstimulation. The main difference I see here within the autistic community is between seeking or avoiding a structured life. Some insensitivity might play a role too, e.g. ignoring social cues, but I think this is overestimated.
Yes, I actually wrote a piece about High Sensitivity and the Autism Spectrum (and Aspergers, in particular) a long time ago, but ended up pulling it down because of the constantly fluid nature of how "The Spectrum" keeps getting redefined. Which is a polite way of saying that I got tired of answering messages from annoyed people saying "That's not what we call it, anymore!"
I do believe there's a high degree of overlapping, and because there are so many formal studies being done now, there's constantly a better understanding coming to light.
Perhaps we also have to consider the tendency of modern society to "medicalize" aspects of the human condition that once upon a time were merely considered to be within the frame of "normal experience," rather than a condition.
Yes, I can imagine the naming debates would get tiring, I even see debates on Twitter about "person with autism" or "autistic person". This is a community which has extreme disagreements about the importance of names, not just about which names to use. And then there are do-gooders or parents of one autistic child who think they can speak for us.
I'm still interested in your perspective, though.
Resisting medicalization is something I also hear from people who'd say "Just act normally!" (not you), so that makes me suspicious. There are real medical issues when you can't stand being touched or when small talk stresses you out, for example. Issues that would be easy to deal with when others accept that you're different. Simply convincing my family that I really can't drink coffee although I'd love to was a struggle that took years.
I do think it's unfeasible for everyone to get a medical diagnosis. Personally, I refuse to go through that process, since it would involve the doctor talking with someone who knows me well about my behavior.
Btw, congrats with 20 years of blogging! That's impressive.