*draws a demonic circle and kills a chicken on skyrim to revive the thread*
So, lately I've been studying this thing a lot. It started cause a friend asked me to explain it to her but I figured in order to do so I had to dive deeper into it...and dive I did!
Ignore the 16personality quiz that we have all done in this thread. It's very popular, but it's also very bad at getting accurate results in many cases.
The thing is the 4 letters are actually just a synthesis of cognitive functions which every type uses in different ways
introverted intuition(Ni) vs extraverted intuition(Ne): the first is about putting things together and creating patterns and forming a vision, while the other is about taking things apart and looking at diverging possibilities
introverted feeling(Fi) vs extraverted feeling(Fe): whereas the former is about prioritizing personal values and self directing one's emotions, while the latter prioritizes the needs or opinions of others before one's own
introverted sensing(Si) vs extraverted sensing(Se): Si is about relying on known experiences and familiar knowledge and customs, Se is about living in the moment and being able to address things with immediate reaction
introverted thinking(Ti) vs extraverted thinking(Te): where Ti is about going through long internalized monologues to form decisions, while Te is about organizing the mind in very structured ways to optimize one's efficiency
The way they are stacked(dominant, auxiliary, tertiary, inferior - alternating between introverted and extraverted functions)can give some incredibly accurate personality assessments of a person.
Mind you, this has no clinical value and psychologists will kill you over it, but this is still immensely useful at least for people like me. As an aspie I've always had extra trouble when trying to understand others and why they do what they do - now that I've studied the functions I find myself a lot more capable of navigating through other people's minds and reasons, it has made me more perceptive, less dismissive(though I still have nothing but contempt for stupid people - it's part of being INTJ!)and more appreciative of people that have different minds from mine(but not for ESTP). I'm even pretty good at "typing" people from simple observation now!(I do it with many fictional characters for fun).
For a quick reference at how every type is stacked in terms of functions:
Dom-Aux-Ter-Inf: the dominant function is how the mind is wired by default and the primary focus of the type; the auxiliary is how the main function is supported; the tertiary is the comfort function normally used as support but becomes very *** and transforms into dominant when the person is under stress; the inferior is a function that is used either improperly or becomes abused and it's very difficult to balance until the person becomes more mature in life
ISTJ
Si-Te-Fi-Ne
ISFJ
Si-Fe-Ti-Ne
INFJ
Ni-Fe-Ti-Se
INTJ
Ni-Te-Fi-Se
INTP
Ti-Ne-Si-Fe
ISTP
Ti-Se-Ni-Fe
ISFP
Fi-Se-Ni-Te
INFP
Fi-Ne-Si-Te
ESTP
Se-Ti-Fe-Ni
ESFP
Se-Fi-Te-Ni
ENFP
Ne-Fi-Te-Si
ENTP
Ne-Ti-Fe-Si
ENTJ
Te-Ni-Se-Fi
ESTJ
Te-Si-Ne-Fi
ESFJ
Fe-Si-Ne-Ti
ENFJ
Fe-Ni-Se-Ti
I could go more in depth about each type but unless someone gives a damn I'll leave it like this for now.
Reading back I had to delete a comment where I jokingly(and I insist I was joking)said I was looking to date an ENTP. Knowing better now I would probably punch the ENTP at the first argument.