As a kid I was identified as gifted-lite (the diet coke of giftedness: just one calorie, not gifted enough :) after taking the CTBS/CCAT tests. Apparently I was at or above giftedness cutoff on two of the parts but below it on the third part.
But I showed them: my assessed quasi-giftedness was no match for my persistent lack of motivation.
From your perspective, as someone sitting mid-way between the two, I can appreciate how that distinction might not seem as clear-cut. It's something I hadn't considered before; thank you for that.
Which is to say, it's really silly to draw much of anything meaningful from an internet poll.
"However, according to McCauley and Myers, this is not necessarily related to intelligence; rather, it is related to the match between the academic characteristics of IN types and the content of aptitude tests. When gifted adolescents are compared to general high school students according to their preference for intuition, they are more likely to enjoy solving new problems and dislike doing the same thing repeatedly. They also are conclusive, impatient, and interested in complicated situations. They might be more interested in novelty according to the type theory."
My take: they've become bored as hell, conditioned over the years of idiot level race-to-the-bottom schooling to hate doing what they're assigned the way they're supposed to do it because they don't require as much repetition as other people apparently do in order to "get" things. To get any intellectual enjoyment, they had to find interesting stuff on their own.
I'd also suspect that the introvert part comes about mostly because of the various social stigmas against doing well in school; later in life, a lot of people that were silent outcasts in school really come out of their shells once they're around people that value skills other than throwing balls around.
In other words, my take is that there may be a causal relationship here, in that "giftedness" (whatever that really means) tends to force people towards a certain personality type in most high school environments.
I'd be very curious to see if these results continue to hold in cultures where there is less teaching to the bottom and more respect for academic talents.
Some of the dumbest people I've ever had the displeasure to interact with were in the gifted program, and a couple of the smartest ones were not; it's a rough measure, certainly, but that doesn't mean it's altogether meaningless. It probably has a decent but not overwhelming correlation with actual intelligence, whatever way you may wish to define that.
Edit: It's also worth noting that more and more districts don't have gifted programs any more, due to an increased emphasis on getting the lowest scoring students past thresholds for NCLB.
I'd be curious to hear what others here thought of these programs if they were available - the one that I was a part of actually pulled us out of school one full day per week, and let us choose and work on our own projects, so I found it very valuable, far more than the missed schooldays would have been, but I know there's a lot of variability in these things.
What of the non-gifted student? Is he deaf, or is his muse mute?