^ In the book, that excerpt is from a section discussing Jung, and his definitions of function attitudes both before and after that excerpt. So it is unclear how she defines her labels of introversion and extraversion BUT seems to lean on Jung to do it. The gist of what's she's saying is that 30% of extraverted people (ie people who get their energy from being around other people) are HSP's. This is how she explains what an extravert is.
Honestly, who knows what anyone is arguing here. You and mal keep using the wrong word to describe the trait anyway, since hypersensitivity is not a word I have found used in the HSP or Jung circles, but you seem to have latched onto it since it is listed on mal's introversion questionnaire. You quoted Jung's "hypersensibility" which means more to respond to emotional or artistic stimuli. Hypersensitivity is more physiological in nature. Just say sensitiveness or "innate sensitiveness" or my glorious made-up word, ultrasensoriousness. It's a moot point perhaps, but I think it best to avoid the use of that word. It gives me a rash.
As for HSP = "innate sensitiveness", the following is likely closer and generous too: HSP ≈ "innate sensitiveness" - it loosely fits, at least Aron seems to want it to fit in the book, and her later research seems an effort to suss out why it doesn't really fit or make it fit better. The problem lies in that Aron's research shows a closer correlation to other factors than introversion to be an HSP, notably being female and having a difficult childhood. Do you have a difficult childhood because you are HSP or does being an HSP precipitate a difficult childhood? To what extent does the infant experience color our childhood and subsequent development? I don't doubt we are born with innate traits, and do believe we all have an internal set-point for what we find over-arousing. There is much research to be looked at studying sensitive babies, yet I don't know if there's any widely accepted answer to that question either.
So, the following statement is true to my investigations performed so far: HSP ≠ introversion. Problematically however, from what I understand of Jung's text, introversion = "innate sensitiveness" making HSP ≈ "innate sensitiveness" even more tenuous. The paper linked above to Aron's 2004 study doesn't appear to account any further for the differences, but I'll read it more throughly when I have free time. Interesting.
My caveat: I have not performed the appropriate level of research on this topic so am not making a formal argument. To me, this is an open-ended conversation, I am not here to prove one way or the other, only share information and discuss. If I was putting together an argument, I would be much more structured, would research this deeply, and assemble something far more bullet-proof.
I have still drawn no conclusions on typing Lily Flower's son. I'm not swayed on the arguments from Jim or mal as they offer little to further define type.
If I were to speculate based on how this feels to me, I do think he seems an introvert, he's likely more intelligent than the IQ test would indicate, and way back at the beginning of the thread, I provided links to read about ITP and INJ children, as found on personalitypages - so that's an indication of what immediately comes to my mind. We all tend to see what our filter lets through, so if he is NT with two "feelery" parents he would seem quite distant and almost "backward" to them from a social standpoint, which they then could easily extrapolate to other areas, such as intelligence. He needs fuel to bring out the side of him that will want to learn to be more socially aware. People can be the conduit through which he can gather more data and this will open him up to the value of that interaction. And, I still think the Dx of dyslexia is a possible avenue of further exploration for assessing whether he has any mechanical difficulties with eyesight. A high %age of kids, speculated as many as 50%, actually have a vision problem, not dyslexia.