AnalyticalEngine wrote: ↑Thu Feb 09, 2023 6:26 pm
The question is, therefore, how much of your temperament is fixed and how much of it was caused by the environment?
If you "believe" in MBTI, temperament is a bit more complicated than a linear combination of nature and nature. Personhood starts by developing the dominant function first and it gets developed by using it. As it gets more developed, it gets used more, and it quickly becomes the preference. (You get good at what you practice.) The dominant stage starts once personhood starts, that is, usually around age 3, post-toddler, or so when humans enter the "autobiographical" stage and begin to be able to tell stories about themselves (as a person) and construct their own idea-space and (self-)reference back to those constructs.
This dominant function will be either introverted or extraverted. Likely set by brain chemistry. For example, mine is Ni.
In order to connect the brain with the world, it will gain auxiliary support from another function that will extraverted or introverted---the opposite of the dominant function. Mine is Te. This is support function develops during school age. (The primary function keeps developing but it might not be as "interesting anymore"(*).)
Brain first, then world ("think before you talk") will become introverts. World first, then brain ("just do it") will become extraverts.
How do I know I'm a Judger and not a Perceiver. This has to do with which function leads and whether you're introverted or extraverted. Is the leading function a perceiving function (N or S) or a judging function (T or F). If you're an extraverted judger, you lead with the judging function; extraverted perceivers lead with their perceiving function. Introverts are the other way around---they keep their primary function for themselves: brain first, then world.
As the person grows older or more accurately matures more, the tertiary function becomes interesting. This can happen between, say early teenage years or even late, like middle age. In my case Fi. Since my emotions are mainly centered around NiTe, I became interested in ethics, morals, ... systems for doing the right thing. For example I started questioning the validity of religion at age 13 and ultimately decided it was not for me. If my tertiary had been centered around something else, I might have developed feelings centered around humans or friends or relatives instead. As it is, I have a stronger emotional reaction to principles than other humans. It is sadder to me when a principle dies than when a human dies. This is somewhat unusual cf. most humans.
Maturing more, we come to the inferior function. For me it's Se. It's the only one left in the stack (the other ones are already taken). It is the opposite version of the dominant function---otherwise there would be too much competition. In my case it's expressed as sports and physical activities.
Why do people appear to test differently from time to time? Doesn't that mean they change their temperament. Well, not according to the theory. This happens insofar people start focusing a lot on a given function; say due to nurture. Lets say I develop a strong interest in my inner emotional space. I go to therapy or somesuch talking about my feelings. Given how much I focus on F-type perspectives, this takes over my general behavior; and now I start testing as an INFP ... because NiTeFiSe was rearranged to FiNiTeSe (<- this is not a type). And now we have confusion. This is where the P and J preferences become weak and people start getting X's in their results. In my case, studying math meant a lot of Ti practice, so I have a strong Ti which comes out in my behavior, except I don't really have a preference for it. It's basically the same problem when so many Americans test as extraverts because unless you're "fun and outgoing", there's something wrong with you in US culture.
(*) For example, one reason I tested eNTJ (TeNi...) on my first test may be that school and interests focused heavily on Te interests while the F dimension was mostly ignored.
Somewhat rarely, people will get interested in their shadow and develop the dispreferred functions. That's just the temperament with e and i flipped. @daylen put out a conjecture than Kegan2~first two functions developed, Kegan3~4 functions developed, Kegan4~6 functions, and Kegan5~all 8 functions. That is a strong assertion but very interesting.
Add: Another way to think about it is to use the CAR model. In this case personality develops from the driver to the spouse ... and then on to the children. Mature individuals may end up with an 8 person minibus. However, while, say, the 10 year old may be put in charge in a given situation, the seating order ostensibly doesn't change, that is to say, the original order just seems more right even if the 10 year old spends a lot of time behind the steering wheel, say. Another way of saying it is that insofar temperamental changes are possible, they takes many many years to unfold. What usually happens as people mature is that they become more mellow... capable of using more functions and applying them appropriately.