I've known I was INTJ for nearly two decades. I took my first MBTI test around 1993. I've found personality theory interesting ever since, though I never pursued it the way some members here have. INTJ fit me well, so I never really doubted my type.
I've been an active member here for a couple of months now, though I've done more reading than posting, and I've learned a lot more about personality typing. My background before joining this forum was mostly Keirsey, but if cognitive functions are the best way to determine type -- or even a remotely valuable tool for determining type -- then I'm not INTJ after all.
That's kind of hard to give up, because it's been part of my identity for a long time. There's very little doubt I'm a T, and none at all that I'm an introvert. But my N preference isn't terribly pronounced, so I initially considered ISTJ. That doesn't really fit, either. Going by cognitive functions, there is basically no way I'm not INTP. Descriptions of INTP fit me well enough to be plausible, and my judging preference has never been overwhelming, but if I retype myself as INTP, I'm really just putting faith in the functions. Ti > Ne > Si > Fe sounds right to me. In fact, I don't think any of the other 15 combinations is even credible.* But P still doesn't seem right to me.
I realize self-reported tests need to be taken with a grain of salt, especially because I know enough about MBTI to manipulate my own results, but I always test J. I'm sure I've tested P at some point, but I usually come back with a discernable judging preference. My three most recent results, all from the last six months:
44 I, 38 N, 25 T, 67 J
I 9, E 5 / N 9, S 5 / T 10, F 4 / J 10, P 4
Introverted (I) 73.53% Extroverted (E) 26.47%
Sensing (S) 54.29% Intuitive (N) 45.71%
Thinking (T) 63.16% Feeling (F) 36.84%
Judging (J) 55% Perceiving (P) 45%
When I joined this site, I wrote in my introductory post that my judging was "probably at an all-time high now". I tend to prefer planned events and sometimes have strong adverse reactions to the unexpected. I like to know the where and when of things.
Am I putting too much faith in functions here? That's basically the whole basis for questioning my INTJ designation. Maybe it's a mental trick I've been playing on myself, but I generally feel most in tune with INTJ posters here. I'm relatively new to the forum, but some of you may know me a little bit by now. If anyone has feedback, I'd appreciate it. FWIW, my enneagram type is either 5w6 or 6w5. Does anyone have opinions? Questions?
I feel confident that we only need to consider INTP, INTJ, and ISTJ.
* Scrambling the order, maybe, but I'm definitely not ISFJ, ESFJ, or ENTP.
** Goodness, lots of INTJ/INTP uncertainty recently.