Introduction
Determining Type Dynamics
Type Development
Link to Table Format
The INFJ-List discusses type dynamics and type development from time to time. Though these theories are very important to type theory, most popularly available books don't discuss these topics. I suppose the authors consider them "advanced" topics.
There is a fair bit of debate about type development theories and some debate over type dynamics too. I will explain the commonly accepted theories and leave the variations for some other time.
First type dynamics. In a four letter type code, the two middle letters are the most important. These are the two functions that you use most. The outer two letters help us to understand the orientation of the middle two letters.
The first letter (E/I) is the orientation of the dominant function. It has something to say about which world you "live" in. The second letter (S/N) is the perceiving function, which is how you go about gathering information. The third letter is the judging function (T/F) and is how you go about drawing conclusions. The last letter (J/P) was added by Myers and Briggs (the rest came from Carl Jung) to specifically help with type dynamics. The J or P indicates which of the middle two letters you extravert, the judging function or the perceiving function.
Your top two preferred functions show up in your type code, and the rest are interpolated from that. The first function is called the dominant, the second favorite the auxiliary, the third favorite is the tertiary function and the fourth is the inferior.
There are a total of four functions (S, N, T, and F) but there are two orientations to each function, introverted and extraverted. So there are a total of eight combinations when you put it all together. The common short hand used in type circles is to capitalize the function letter with a lower case subscript. Extraverted feeling would be Fe, introverted feeling would be Fi, and so on.
Type dynamics describes four functions for each person (dominant through inferior) but does not address the other four functions. There are a large number of theories that address this and none has emerged as a dominant one. Everybody has all eight functions and uses them at some time, but there's no agreement on where the four "neglected functions" fall in a person's hierarchy of functions.
There is a step by step procedure you can go through to determine the type dynamics for a given type. I'll start with INFJ:
1. Determine which function is extraverted. The last letter tells you this. In this case J. That means the judging function is extraverted: Fe in this case.
2. The other function has the opposite orientation from the other. So the N is Ni (introverted).
3. The first letter tells you which of the functions is dominant. In this case I, which means the Ni is the dominant function.
4. The auxiliary is the other middle letter, in this case Fe.
5. The tertiary is the same type of function as the auxiliary, but the other type. There's a raging debate about it's orientation, some say the orientation is supposed to be the same as the auxiliary, some say the opposite, and some say it could swing either way. Jung's original theory says that the psyche seeks balance and so each camp claims that the tertiary oriented one way or the other would balance the psyche. I will denote the orientation with a '?'. In this case the auxiliary is Fe, so the tertiary is the same type of function (a judging one), which would be T?.
6. The inferior is opposite to the dominant in orientation and the same type of function as the dominant (but the opposite one). Since the dominant is Ni in this case, the inferior is Se.
7. The function order then comes out as Ni, Fe, T?, and Se.
8. Ne, Fi, one side of T, and Si are left out of the mix. Pick a theory to how they get integrated.
The dominant function is the one that is most conscious to you and the inferior least conscious. The inferior rears up and takes over sometimes. This is often called "the grip". When in the grip we're a bad caricature of our opposite. Everything negative and none of the good attributes. If you consciously work on the inferior function, you can lesson grip reactions. Though exercising the inferior function always takes energy, while exercising the dominant will build energy.
As another example, I'll do ENFJ:
1) Extraverted function: Fe.
2) Introverted function: Ni.
3) Dominant function: Fe (first letter is E).
4) Auxilliary: Ni
5) Tertiary: S?
6) Inferior: Ti
7) Function order: Fe, Ni, S?, Ti.
As you can see, even though ENFJs are only one letter different from INFJs, the function order comes out quite differently.
Type development is a theory about when these functions develop. In an ideal situation, a small child will develop the dominant function first, then the auxiliary as a teenager, then the tertiary in their late 20s and early 30s, then the inferior at mid-life crisis.
There are many reasons why this scenario doesn't usually play out this way. For one, introverts need to develop an extraverted function (their auxiliary) at a fairly early stage in life. Adults are going to worry if they don't extravert "something."
Family and cultural influences can have an effect too. F men and T women are not culturally acceptable, so they're going to have cultural pressure to develop the opposite function from an early age. Even if it's their inferior.
See this information in table format.
"It is with logic that one proves;
it is with intuition that one invents."
Henri Poincare