Myers-Briggs Type Indicator and Cognitive Theory

I've been meaning to write on this subject for a long time now (and in general to post content more frequently!) but my lingering insecurities, combined with excessive perfectionism, have made it difficult for me to get motivated enough to produce content of sufficient quality (as determined by my self-judgment) to warrant publication in a publicly accessible location (even despite my self-professed informality at the outset of my blogging adventures back in 2013). Luckily for me, I recently fortuitously discovered a fantastic blog written by a gentleman who calls himself Eevee (after the cute and fluffy Pok√©mon creature of the same name) and whose interests and writing style intersect with mine to a non-trivial extent. I was initially directed to his blog by my manager at my day job, who shared Eevee's highly detailed and informative post on the myriad things wrong with the PHP programming / web scripting language in our #random Slack channel. Since this discovery I have continued following Eevee's blog and hungrily devouring his excellent writing on various subjects (mostly related to programming, since that is his main area of expertise), going as far as to support him on Patreon (a useful site for supporting content creation, despite their unfortunate recent hack).

So what motivated me to write this post? The second post so far that I have commissioned Eevee to write (the first having been on the thorny but fascinating subject of the War on Drugs) was dedicated to the Myers-Briggs Type Indicator, a "personality test" (a term with which I take some issue) that places people into one of 16 categories that indicate certain broad patterns of thinking and behavior specific to each type category. I had already done extensive research on the subject, having rekindled my interest in the subject this past spring while in the process of looking for a job and working with a talented Arlington County career counselor to this end, but I was curious to get Eevee's take on this subject given my strong suspicions that he, like me, is an INTP. I was pleased (but not surprised) that he produced a solid (and humorous, as is his trademark) post on the subject, and after reading it I couldn't help but comment on it and offer my own thoughts on the theory behind the MBTI (essentially a semi-brief and informal summary of my research findings). My comment on his post follows below (relevant links and formatting added after initial "publication").
Thanks for indulging me in what was honestly mostly a fishing expedition on my part to get you to cough up your own type to confirm my suspicions (I was 95% sure you would test as an INTP given your writing / discourse style). I have spent an inordinate amount of time studying MBTI theory, buying several e-books in the process (of varying quality) and devouring them in a relatively short time span this past spring. Oh, and I also read a bunch about socionics, which is the Russian take on MBTI that introduces a bunch of wacky new stuff that sort of meshes with MBTI in most places but seems to diverge a bit in others. Suffice it to say that socionics makes the MBTI cognitive stack theory look like it was written by a toddler, in the sense that it goes way more in-depth and actually proposes an ordering of 8 (!) functions instead of just 4, although it still manages to come up with the same(-ish) 16 types due to some fairly complicated theoretical calculus that does not allow certain combinations (because obviously there exist considerably more possible ways to arrange 8 distinct things than just 16).
OK, so back to MBTI itself. It tends to get a bad rap because it gets frequently misunderstood / misused (especially by corporate folks, as other commenters have pointed out) to put people in boxes (as you mentioned in your post). I totally get that, and I don't think it's fair to deny someone a job (or anything really) just based on their type (which can often be misrepresented by the actual MBTI instrument since people's general mood / affect at the time of taking the test can have an impact on their responses and hence their computed type). That being said, I have consistently been impressed with the predictive capabilities of the theory, in that certain types have tendencies to think and act in certain ways, in accordance with the ordering of their cognitive functions. I've made it a personal sport to try to guess at the types of the people I interact with regularly (and even the types of fictional characters from movies / TV shows), and not just make wild guesses but actually examine their outward behavior and theorize about what that implies about their inner cognitive preferences (and why).
I think that the superficial "horoscope" approach does the theory a great disservice, because it tries to boil down what is actually a pretty nuanced theory into generic-sounding personality profiles that may or may not match up with a person's experience in his / her own life. The problem is that MBTI is more of a high-level blueprint of how a person makes decisions (Judging) and takes in information from the world (Perceiving), which can manifest wildly differently in people based on the sum total of decisions they've made along the way in their lives and the specific experience they've had just living life, rather than a concrete and rigid explanation of every facet of a person's personality (which is most definitely not the goal of MBTI).
Experienced MBTI practitioners / researchers who actually know their stuff will in most cases shy away from calling it a personality typing system and instead describe it as a system for teasing out a person's cognitive preferences. This approach leaves a lot more leeway for personal differences, since preferences (whether influenced by nature, nurture, or more likely an interplay between the two) can manifest very differently based on idiosyncratic and environmental factors. Obviously the same falsifiability criticism still applies, since we still don't know why or how the theorized cognitive functions (Ti / Te, Ne / Ni, Si / Se, and Fe / Fi) actually come about and what they mean in terms of a person's actual neurological make-up (e.g. whether they correspond to specific neural networks that can be discerned in a lab setting).
For what it's worth, I really identify with my own type (surprise, surprise, I'm an INTP too) and am almost creeped out by how well Dr. A. J. Drenth's e-book on INTPs (oh yeah, he's an INTP too) describes my inner mechanisms and what they entail in terms of strengths and weaknesses (yes, weaknesses). The fact that a complete stranger can have this insane amount of insight into how I think and behave is a big part of why I'm a believer in MBTI, because without some predictive validity to the theory the chances of this happening are infinitesmally small (since getting so many things right by pure chance / guessing is highly unlikely – think of the whole "monkeys with typewriters eventually writing Shakespeare's works" thought experiment).
Not only that, but I have developed a pretty good "INTP radar", sniffing them out based on the almost immediate intellectual kinship I feel with them based on written or oral expressions of their ideas and theories. A couple of my friends are INTPs (not to mention my French teacher and mentor in high school), and the level of discussion about pretty much anything that I can have with them is virtually unmatched in the amount of intellectual satisfaction it provides (versus having similar conversations with people of other types). This is not to say that all INTPs are necessarily geniuses or anything, because I'm sure there are plenty of "dumb" INTPs out there, but the ones I've interacted with have generally been consistently insightful with regard to a wide variety of topics I care about (and plenty that I don't care that much about).
There's something magical about having my Ti and Ne interface with that of another person, whether via written medium or verbally. As Dr. Drenth puts it in his INTP book: "One of the beautiful things about written works is they can be carefully selected to match the INTP's current concerns and interests. Books may do for INTPs' Ne what new sexual experiences might for STPs or music for Feeling types." Of course this can be expanded to any piece of writing, like well-written and researched blog posts, which at least to some extent explains my ready willingness to buy a lot of books and just generally financially support the creation of quality content (e.g. via Patreon) from authors whose intellectual authority I trust.
Anyway, I could go on and rant about this stuff a lot more, because it is infinitely fascinating to me, but I guess my point is that there's a lot more depth to MBTI than most people realize, and I don't think it's fair for people to write it off as just another horoscope analogue, because it's so much more than that. It is certainly problematic, though, that lots of people have thoughts on MBTI, not all of which do the actual theory justice, and also that the theory itself is in my opinion not fully developed yet and can't really ever gain an aura of scientific acceptance until we figure out the underlying mechanisms by which these magical cognitive functions actually come about (e.g. by creating artificial intelligence / neural networks that process information in a way that approximates how people do it using their MBTI cognitive functions). Still, at least for me it's fun to think about this stuff and try to use it to better manage my real-life relationships with others based on a deeper understanding of how types interact with each other, understanding the limitations of not just other people's types but also my own and trying to work around them to develop more harmonious and fulfilling relationships with others (something that will always be a work in progress, of course).
I have a lot more thoughts on the MBTI and socionics, most of which will probably never see the light of day (such is the way of the INTP), but I think this is a decent enough approximation for now, not to mention that Eevee's post is already chock-full of information that I'm not going to reproduce here, for the sake of avoiding unnecessary redundancy and also sending him some web traffic (ha, just kidding, he gets way more traffic than I do since he's a way more prolific writer and a better programmer than I am). In any case, I will continue to refine my understanding of MBTI theory and apply it to my own life, and hopefully the theory itself will continue to be developed and maybe even validated scientifically (wouldn't that be nice!) at some point in the future.