Yeah, I think that's part of it. I think that's also part of how people get into dominant-tertiary loops. Insufficient extroversion, i.e. focus on the ego and unwillingness to go outside one's comfort zone, underdevelops the auxiliary function.
I actually thought about this on my walk today, and I think the thing about my auxiliary function is that it takes conscious effort, whereas my dominant function seems to come naturally. I guess whether or not you use conscious effort depends on whether or not you have the will to use the function. This makes me wonder if there are some types that are less willing to use their auxiliary function, because the dominant and tertiary provides them with a lot of what they need.
I often find that, if I don't use intuition, there is nothing for my dominant function "to do" that it hasn't done before (si? ), and so I get bored. I wonder if some types are more "internally fueled" and so don't find it as useful to "go out of their comfort zone" ( as you put it) and extend the conscious effort.
Ni is more abstract than Fi in my opinion because it incorporates all perspectives and multiple dimensions. Not being an Fi user I can't 100% say what it's like, but it seems to me to only deal with a couple of axes- that of one's relationship to the environment, and valuable vs. non-valuable- so in this way it is more linear and concrete. Ni sees from all sides, including inside out, to see an entire structure, and so it would include at least 3 dimensions.
I really don't have a handle on Fi at all. I know what Se is, I just happen to suck at it. It's always at the bottom of my function tests. I sometimes wonder if my difficulty with understanding what Fi is can be related to the fact that it's actually very simple... this is good, this is bad. Not sure, really.
I'm starting to get a handle on introverted intuition, and I can definitely see how it relates to the INTJ stereotype of planning for every contingency. It's really Ni that allows them to do that, less than Te. ISTJs don't seem quite as prepared for the "unexpected", which makes sense, given how much of Si is related to experience.
Looked at this way, Ni is actually kind of cool, but I can also see how it would impede discussion when it's too "married" to Fi. Fi seems to take people requiring explanations as signs that someone mistrusts them. (I've noticed NFs discussing this phenomenon, so it's not just something I made up to explain why my ex annoyed me.)
Ti-Si..... "that'll never work. It's not worth trying because I've seen it fail too many times before"
Ni-Fi.... "What... you think I'm lying about this, and that I haven't actually thought about this a lot?"
Could this be the root of the INTP/INTJ conflicts? It seems like in both cases, the tertiary is really "pulling" the dominant in a certain direction (the weight of the unconscious?) but the person isn't aware that the dominant isn't actually calling the shots.
Edit: I just thought of something else. Fi seems to be very good at understanding others' feelings, so it contains a very "watery" quality because it flows into others' perspectives. This adds some amount of abstraction. But once again it is along a continuum of other people vs. me, and it all relates back again to the self; so I think overall it still contains fewer dimensions than Ni (Ni being more than three I suppose). But it's true that they have a lot of similarities. Ultimately I think a judging function has to be less abstract than a perceiving function, because it's always going to organize things along a continuum, where a perceiving function will only go so far as to relate things to each other.
Hmmm... yes. I can see Fi doms explaining how they "got there" now. It's just that it looks nothing like the way Ti doms do it, so I assume that they don't do it at all.
I just thought of something which might contradict this. This shows my N bias. in terms of abstraction N>S, N>F, but is S>F? Se seems like the least abstract function. Sure it's less organized than Fi, but it should really be the most concrete of the functions. So I guess judging functions are more organized, not necessarily more abstract.
If I am to rank them in order:
Ni-Fi-Ti-Ne-Si-Fe-Te-Se
If this is true, this makes INTJs more abstract than INTPs, I would think, despite the fact that INTPs seem more outwardly "dreamy".
Although, there is the Te all the way at the other end of the scale. I suppose whether or not an INTJ make conscious use of Te will make a very big difference. This is actually very much in line with what I had already speculated. I hypothesized that the extreme variation in how my discussions with INTJs go is related to the auxiliary.