4. Vulnerable function
The vulnerable function is also called the Point or Place of Least Resistance (PoLR) or sensitive function. The element in this function creates a feeling of frustration and inadequacy. A person does not understand the importance of this element entirely, and it can easily lead to painful consequences if not adequately considered.
However, to directly engage this function creates feelings of insecurity and distress.
One reason why the vulnerable function is so difficult to engage is because three other conscious functions come before it, making this one the most difficult to comprehend. Often an alternative approach may be found from the view of the mobilizing function. Because of the psychological disincentives to using the vulnerable function, people usually try to ignore information related to it, and in extreme cases do so even in situations where it is most relevant. Even with a theoretical understanding of how this element works, it is difficult to turn it into practical norms of behavior. One can "develop" the vulnerable function by recognizing that it is actually important in certain real-life circumstances. Even if the subject recognizes this, he will still usually try to avoid taking responsibility for it himself, or develop a minimalist or non-traditional approach (possibly using other functions) that is enough to satisfy one's own needs. The presence of a dual usually dissolves any concern there might be about how to approach matters of the vulnerable function.
A type with PoLR Fe (ILI and SLI) does not see the point of activities revolving around excessive displays of emotion or behavior that does not reach a concrete or tangible outcome. They would rather keep conversations serious and to the point, for he/she is overwhelmed by such emotional expression, making it quite difficult to express themselves. In social interactions they will make a serious effort to reduce their level of emotive expressiveness such as being too joyful or sad, believing that showing these signs will make them vulnerable to be influenced by others. They don't hold quite a high standard for how people as a group feel about something (even if outnumbered by many when making a personal decision), and instead value situations where they can speak their own subjective opinions and feelings freely.
(Does this sound like Fucking Fe inferior and valued?)
A type with PoLR Ne (LSI and ESI) has a difficult time understanding ideas that seem new or novel, especially when it has no tangible effect on their lives. Leaving little to chance, they are able to plan out their lives for years ahead of time. This results in difficulties handling unexpected problems in their lives that put a halt on their usual pursuits, and they tend to fear all the possible "what-if's" when those problems prevent them from seeing a clear future. When unsure about something, these types can either avoid making any changes at all or making too quick and reckless of a decision, either of which resulting in missed opportunities.
(Does this sound like Ne Inferior/valued?)
A type with PoLR (EIE and LIE) has little patience for sitting back and focusing on how they can physically better themselves in the moment, especially if they are involved in what they view as a very important matter. They would much rather try to act on their long-term priorities instead of their physical comfort, resulting in problems such as an inability to be aware or care about present realities, failure to realize the physical or mental strains they are placing on themselves, and being generally unable to relax and take the focus off of their long-term pursuits. (Does this sound like Si inferior/valued?)
A type with PoLR (SEI and IEI) tends to reject facts given from a source which they are personally unfamiliar with, firmly believing they can make their own decisions that are solely based on their own perspective and reasoning about it. They will tend to become defensive when questioned about their rationale or efficiency, pointing out that there is no such thing as objective "fact". Also, these types experience a significant level of stress in tending to day-to-day must do's and responsibilities in life (like routine maintenance or working productively), manifesting itself as a general laziness or hyper-diligence.
(Oh, look, it's you. This doesn't sound like a valued inferior either, I'm afraid)