Reading through this thread I've found the overall feeling to be an attempt at understanding how we perceive antithetical dominant feeling functions, and I think everyone here has a well rounded understanding of IF and EF.
Just to shed a little more light, I'll just quote from Carl Jung on Introverted feeling and Extraverted feeling in how he views it.
Introverted Feeling:
"Introverted feeling is determined principally by the subjective factor. This means that the feeling-judgment differs quite as essentially from extraverted feeling as does the introversion of thinking from extraversion. It is unquestionably difficult to give an intellectual presentation of the introverted feeling process, or even an approximate description of it, although the peculiar character of this kind of feeling simply stands out as soon as one becomes aware of it at all. Since it is primarily controlled by subjective pre-conditions, and is only secondarily concerned with the object, this feeling appears much less upon the surface and is, as a rule, misunderstood. It is a feeling which apparently depreciates the object ; hence it usually becomes noticeable in its negative manifestations. The existence of a positive feeling can be inferred only indirectly, as it were. Its aim is not so much to accommodate to the objective fact as to stand above it, since its whole unconscious effort is to give reality to the underlying images. It is, as it were, continually seeking an image which has no existence in reality, but of which it has had a sort of previous vision. From objects that can never fit in with its aim it seems to glide unheedingly away. It strives after an inner intensity, to which at the most, objects contribute only an accessory stimulus. The depths of this feeling can only be divined they can never be clearly comprehended. It makes men silent and difficult of access ; with the sensitiveness of the mimosa, it shrinks from the brutality of the object, in order to expand into the depths of the subject. It puts forward negative feeling-judgments or assumes an air of profound indifference, as a measure of self-defence.
Primordial images are, of course, just as much idea as feeling. Thus, basic ideas such as God, freedom, immortality are just as much feeling-values as they are significant as ideas. Everything, therefore, that has been said of the introverted thinking refers equally to introverted feeling, only here everything is felt while there it was thought But the fact that thoughts can generally be expressed more intelligibly than feelings demands a more than ordinary descriptive or artistic capacity before the real wealth of this feeling can be even approximate presented or communicated to the outer world. Whereas subjective thinking, on account of its unrelatedness, finds great difficulty in arousing an adequate understanding, the same, though in perhaps even higher degree, holds good for subjective feeling. In order to communicate with others it has to find an external form which is not only fitted to absorb the subjective feeling in a satisfying expression, but which must also convey it to one's fellowman in such a way that a parallel process takes place in him. Thanks to the relatively great internal (as well as external) similarity of the human being, this effect can actually be achieved, although a form acceptable to feeling is extremely difficult to find, so long as it is still mainly orientated by the fathomless store of primordial images. But, when it becomes falsified by an egocentric attitude, it at once grows unsympathetic, since then its major concern is still with the ego. Such a case never fails to
create an impression of sentimental self-love, with its constant effort to arouse interest and even morbid selfadmiration. Just as the subjectified consciousness of the introverted thinker, striving after an abstraction of abstractions, only attains a supreme intensity of a thought-process in itself quite empty, so the intensification of egocentric feeling only leads to a contentless passionateness, which merely feels itself. This is the mystical, ecstatic stage, which prepares the way over into the extraverted functions repressed by feeling. Just as introverted thinking is pitted against a primitive feeling, to which objects attach themselves with magical force, so introverted feeling is counterbalanced by a primitive thinking, whose concretism and slavery to facts passes all bounds. Continually emancipating itself from the relation to the object, this feeling creates a freedom, both of action and of conscience, that is only answerable to the subject, and that may even renounce all traditional values. But so much the more does unconscious thinking fall a victim to the power of objective facts."
Extraverted Feeling:
"Feeling in the extraverted attitude is orientated by objective data, i.e. the object is the indispensable determinant of the kind of feeling. It agrees with objective values. If one has always known feeling as a subjective fact, the nature of extraverted feeling will not immediately be understood, since it has freed itself as fully as possible from the subjective factor, and has, instead, become wholly subordinated to the influence of the object. Even where it seems to show a certain independence of the quality of the concrete object, it is none the less under the spell of traditional or generally valid standards of some sort I may feel constrained, for instance, to use the predicate 'beautiful' or 'good', not because I find the object 'beautiful' or 'good' from my own subjective feeling, but because it is fitting and politic so to do ; and fitting it certainly is, inasmuch as a contrary opinion would disturb the general feeling situation. A feeling-judgment such as this is in no way a simulation or a lie it is merely an act of accommodation. A picture, for instance, may be termed beautiful, because a picture that is hung in a drawing-room and bearing a well-known signature is generally assumed to be beautiful, or because the predicate 'ugly' might offend the family of the fortunate possessor, or because there is a benevolent intention on the part of the visitor to create a pleasant feeling-atmosphere, to which end everything must be felt as agreeable. Such feelings are governed by the standard of the objective determinants. As such they are genuine, and represent the total visible feeling-function.
In precisely the same way as extraverted thinking strives to rid itself of subjective influences, extraverted feeling has also to undergo a certain process of differentiation, before it is finally denuded of every subjective trimming. The valuations resulting from the act of feeling either correspond directly with objective values or at least chime in with certain traditional and generally known standards of value. This kind of feeling is very largely responsible for the fact that so many people flock to the theatre, to concerts, or to Church, and what is more, with correctly adjusted positive feelings. Fashions, too, owe their existence to it, and, what is far more valuable, the whole positive and wide-spread support of social, philanthropic, and such like cultural enterprises. In such matters, extraverted feeling proves itself a creative factor. Without this feeling, for instance, a beautiful and harmonious sociability would be unthinkable. So far extraverted feeling is just as beneficent and rationally effective as extraverted thinking. But this salutary effect is lost as soon as the object gains an exaggerated influence. For, when this happens, extraverted feeling draws the personality too much into the object, i.e. the object assimilates the person, whereupon the personal character of the feeling, which constitutes its principal charm, is lost Feeling then becomes cold, material, untrustworthy. It betrays a secret aim, or at least arouses the suspicion of it in an impartial observer. No longer does it make that welcome and refreshing impression the invariable accompaniment of genuine feeling; instead, one scents a pose or affectation, although the egocentric motive may be entirely unconscious. Such overstressed, extraverted feeling certainly fulfils aesthetic expectations, but no longer does it speak to the heart ; it merely appeals to the senses, or worse still to the reason. Doubtless it can provide aesthetic padding for a situation, but there it stops, and beyond that its effect is nil. It has become sterile. Should this process
go further, a strangely contradictory dissociation of feeling develops ; every object is seized upon with feeling valuations, and numerous relationships are made which are inherently and mutually incompatible. Since such aberrations would be quite impossible if a sufficiently emphasized subject were present, the last vestige of a real personal standpoint also becomes suppressed. The subject becomes so swallowed up in individual feeling processes that to the observer it seems as though there were no longer a subject of feeling but merely a feeling process. In such a condition feeling has entirely forfeited its original human warmth, it gives an impression of pose, inconstancy, unreliability, and in the worst cases appears definitely hysterical."
With that quoted, there's definitely understanding for why IF's feel EF's are flakes and why EF's feel like IF's are selfish, when either have fallen into their imbalanced or "worsed" states.
My IN EF while I'm at work is sometimes comical in knowing exactly what to bring someone, or reading a situation others have difficulty communicating. Given what little experience I have with IF, I usually enjoy most FP's and their amazing ability to create something out of nothing. I view IF to be a much more artistic/creative force than EF, but EF to be a much more personable/giving force than IF, but what do I know.