Background
Myers Briggs codes are 4-letter combinations that categorize the 16 personality types. Each of these codes can be translated into a corresponding "process" or sequence of "cognitive functions." There are 4 functions and they are divided into two categories:
(J) Judging Functions: T = thinking ; F = feeling
(P) Perceiving Functions: N = intuition; S = sensing
The "aspect" of a particular function indicates whether it is extraverted (e) or intraverted (i). So, for example "Fe" would represent "extraverted feeling." With 2 aspects and 4 functions, this means there are 8 total possible combinations of function and aspect:
Te, Ti, Fe, Fi, Ne, Ni, Se, Si
According to MBTI theory, everyone uses all 8 of these functions. However, the personality type determines the *order* in which they are used. Here is a step-by-step process for doing this.
Step-by-step procedure
Begin with the 4-letter MBTI "type" code. The possible letters in this code are as follows:
letter 1: I or E
letter 2: N or S
letter 3: T or F
letter 4: J or P
1. Letter 1 fully determines the sequence of aspects, which alternate.
letter 1 = I (introverted): aspect sequence is [i e i e e i e i]
letter 1 = E (extraverted): spect sequence is [e i e i i e i e]
2. If letter 4 is P:
letter 2 is the first extraverted function
letter 3 is the first intraverted function.
3. If letter 4 is J:
letter 3 is the first extraverted function
letter 2 is the first intraverted function
4. Steps 2 and 3 together define the first 2 functions. The third function is the the dual opposite of the second. The fourth function will be the dual opposite of the first.
5. Functions 5 through 8 are the same sequence as functions 1 through 4.
Example: INTJ
Step 1. letter 1 is I, so the aspects are [i e i e e i e i]
Step 2. letter 4 is J. So, the first e function is T and the first i function is N. Based on the sequence in Step 1 we know that the first i function (N) comes before the first e function (T), so the first two pairs in the function sequence are: N, T, ...
Step 3. does not apply.
Step 4. the third function is F, the dual opposite of T; and the fourth function is S, the dual opposite of N. The first 4 functions are thus: N, T, F, S, ...
Step 5. the remaining 4 "shadow functions" are the same sequence repeated.
So the full sequence of functions is [N, T, F, S, N, T, F, S]. Combining these with the aspects in step 1, we have: [Ni, Te, Fi, Se, Ne, Ti, Fe, Si]
Example: ESTJ
Step 1. letter 1 is E, so the aspects are [e i e i i e i e]
Step 2. letter 4 is J. So, the first e function is T and the first i function is S. Based on the sequence in Step 1 we know that the first e function (T) comes before the first i function (S), so the first two pairs in the function sequence are: T, S, ...
Step 3. does not apply.
Step 4. the third function is N, the dual opposite of S; and the fourth function is F, the dual opposite of T. The first 4 functions are thus: T, S, N, F, ...
Step 5. the remaining 4 "shadow functions" are the same sequence repeated.
So the full sequence of functions is [T, S, N, F, T, S, N, F]. Combining these with the aspects in step 1, we have: [Te, Si, Ne, Fi, Ti, Se, Ni, Fe]
