I went through this when I first entered type, because for one thing, I was dealing with a so-called "expert" who tended to go around saying a lot of people were "mistyped", and the tack was always to push people who thought they were T's to F, and from TiFe to FiTe. Even if you didn't understand the theory quick enough, you must be a slow-witted FP (in contrast to quickwitted TP's), and if you did not get the social vibe fast enough, you were a self-absorbed FP as opposed to a selfless FJ); and "liking" a particular type was even tossed out there at me as "Fi" as well.
And when I first arrived here, this sort of thinking seemed to be prevalent. Look at the early "Mistyped Members" thread and you can see some of this.
But "liking" is not a product of Fi; it's a product of
the ego. Fi would be more attention to things you like, and determining what is wholesome, and using thi sense to make judgments.
Oversimplifications like this are why these misunderstandings occur.
OK, that's good information regarding the early climate of the forum I witnessed and described, and the problem we're discussing. (I had never even heard of this "iNtuitive Central" before, and assumed it was perhaps the influence of the expert I mentioned).
[MENTION=15773]greenfairy[/MENTION], what I find another thing that seems to blur T/F for INP's is the Interaction Style, and particularly that it embodies two possible temperaments, one classic one, and another that is newly discovered.
The typical INTP would fit this corresponding temperament in this other system:
http://www.pastoral-counseling-center.org/Temperament-Area-of-Inclusion/phlegmatic-inclusion.htm
While INFP (And the ISF's who are also the same Interaction Style) might fit:
http://www.pastoral-counseling-center.org/Temperament-Area-of-Inclusion/supine-inclusion.htm
This last one is the new one, recognized only in that system. (So the ISF's basically fit "Phlegmatic" by default, as that was the closest thing in four temperament systems).
But what I find, beginning in my own experience, and some others I've discussed this with, such as [MENTION=7]Jennifer[/MENTION] and [MENTION=10653]SuchIrony[/MENTION], is that when an INTP falls into that latter temperament,
they take on some traits that have become associated with INFP and the ISF's, or even Fe in general. The biggest thing is that Supines have a
higher people-focus and need for inclusion by others, which we associate with F, where Phlegmatics are really more moderate and can “take 'em or leave'emâ€, which would better fit the traditional INTP interaction.
Supine INTP's thus end up with T/F uncertainty, thinking they might be F, but eventually settling on T.
But this based more on
traits; some of them overgeneralized, (like the "liking" things or "emotions" stuff) than functions, so
they tend to strongly identify with Ti, but have these traits that have become associated with Fi, (somewhat largely mistakenly, but then other factors such as "right-brain alternatives" or shadow dynamics can explain things too).
On the flipside, you have [MENTION=6561]OrangeAppled[/MENTION], who's an INFP Phlegmatic, and also had the same T/F uncertainty, but went the other way, from T to F.
So that you could look into as well.