Two Birds in a Tree: Glossary: Meyers–Briggs Type Indicator (MBTI)

A personality typing system by Katharine Cook Briggs and Isabel Briggs Myers based on Jung’s theory of the four functions of the psyche. There are 16 different MBTI types in total based on the following dichotomies: introversion/extroversion, sensation/intuition, thinking/feeling, and judging/perceiving (rational/irrational). From the beginning the MBTI has been especially popular in the world of business; Meyers herself worked with the personnel manager of a major bank who went on to found one of the first consulting firms in the US.

It’s important to remember that one’s “type” is simply one’s preferred method of dealing with the world; this is a type indicator, not some destiny determined by the stars. It only suggests a type. We should be careful to avoid labeling ourselves or others. Jung developed his typology as a way to organize our thinking while exploring the infinite complexity of human psychology; labeling people, even with Jungian concepts, makes that impossible as it reduces that complexity to a single four letter caricature. Even if we get our “type” right, we need to remember that it’s a preference, not a result. And it’s a preference which should, ideally, change throughout one’s life as one proceeds along the path of individuation.

What’s my MBTI type?

The easiest way to find out your type is by taking one of the many free personality tests online (I've listed several sites that offer these at the end of the post). Beware when taking the tests that you don’t base your answers simply on the last incident that happened. You need to think about what you would typically do in such a situation, not what you happened to do in one particular instance. When in doubt, ask someone who you feel knows you well what they think you would do. It's probably going to take some time to work out; I’ve been working on this subject for years and I’m still learning new things about myself and about Jung’s typology.

Personally, I feel that the best way to figure out one’s “type” is to get a firm grasp of the various dimensions of the personality (intuition, sensation, introvert, extrovert, etc.) One helpful thing to do is to figure out which are your weakest functions, and which, in particular, is your inferior function. Just as it’s fairly clear what your two strongest functions are, it’s also generally pretty clear what your two weakest functions are; they’re the two areas of your life that always trip you up. To figure out which one is your inferior function ask yourself where you feel the most shame.

As an INTP, both my thinking and my intuition are fairly strong, so much so that at first I wasn’t sure which one was my primary function and which the auxiliary function. This was especially true because I was trying to figure this out later in life, and as you grow psychologically you often move more strongly into your second function as the first one gets worn out and boring. I’ve always suffered failure in the areas of sensation and feeling; I always struggle to take care of my most basic needs, and I’m constantly embarrassed by my social faux pas. However, while I’m embarrassed by my dirty apartment and inability to keep my finances in order, I’m terrified of and humiliated by my social difficulties, to the extent that I’ve literally wanted to die after having embarrassed myself. That simply doesn’t happen when my sloppy housekeeping or lack of financial acumen come up. This kind of over the top affect is an excellent indicator that the inferior function was touched, as our inferior function is the wound that never heals. And once you know what your inferior function is you can figure out the rest.

Understanding the MBTI Code

The MBTI code notes an individual’s attitude and their two strongest functions; the first letter, the “I” or the “E”, denote whether the person is introverted or extroverted. The two letters following the I or the E denote the two main functions, without indicating which is the primary and which the auxiliary function. Determining one’s attitude and main functions in the MBTI is fairly straightforward. Determining which function is one’s primary function is a little more complicated, especially if one is an introvert, due to the MBTI’s somewhat convoluted method of notation.

In the MBTI the last letter that shows which of the two functions is extroverted; the J or the P (for “judging” or “perceiving,” or the rational and irrational functions). The important thing to remember is that this last letter shows which of the two functions is extroverted. In an extrovert it’s easy; the extroverted function is the extrovert’s primary function. An introvert, however, by definition introverts their primary function. This is what makes them an introvert. Therefore, the J or the P indicates which of the two functions is the auxiliary function.

… Extroverts turn their primary function towards the external world; when you meet an extrovert you can quickly make out their primary function because that is the one with which they will greet you. Introverts turn their primary function inwards; the function they turn to the world is actually their auxiliary function. For example, if you meet an extroverted feeling type who secondarily relies on their sensation, you will see a feeling type. But if you meet an introverted feeling/sensation type, you will initially perceive their auxiliary function, sensation. This is because introverts rely on their auxiliary function to get through life. Introverts hide their primary function (in this case, feeling), unless they get to know you well. This makes introverts seem a bit awkward because they're generally using their second best function when dealing with the world.

- Glossary: Auxiliary Functions

As the MBTI code tells you which of the two functions is extroverted, and introverts extrovert their auxiliary function, the last letter for an introverted MBTI type indicates the introverts auxiliary function, NOT their primary function. Below are some examples

ESTP = Extroverted Sensation Thinking, primary function sensation (“P” means perceiving, which is MBTI for irrational, which are the sensation and intuition functions, hence the primary function is sensation, the perceiving function).

ESTJ = Extroverted Sensation Thinking, primary function thinking (“J” means judging, which is MBTI for rational, which are the thinking and feeling functions, hence the primary function is thinking, the judging function).

ISTP = Introverted Sensation Thinking, primary function thinking (“P” means perceiving, but since this person is an introvert the function indicated by the P – sensation – is the auxiliary function, so thinking is the primary function here).

ISTJ = Introverted Sensation Thinking, primary function sensation (“J” means judging, but since this person is an introvert the function indicated by the J – thinking – is the auxiliary function, so sensation is the primary function here).

If this seems completely counterintuitive and ridiculously complicated you are not the only one. This is literally the thing that took me years to get. The thing to remember is 1) if you’re an extrovert, the last letter indicates your primary function but 2) if you’re an introvert, the last letter indicates your auxiliary function.

Once you’ve figured out your MBTI type have fun exploring the internet for information on your type, and that of others as well. While it’s not good to pigeonhole people (yourself included), you can discover valuable insights into your and your loved ones’ personalities. The MBTI is a tool and as such should be your helper, not your master. But if you know how to use it it’s a very useful tool, and one that should be explored by anyone who’s interested in people and why they do the things they do. If Jung’s theory of typology is the only thing, out of all of Jung’s concepts, that you ever master it will still help you enormously in understanding yourself and others.

Typological analysis determined by written tests can be helpful, but it can also be misleading. Such tests are collectively based and static; that is, their validity is statistical and time-specific. They may give reasonable picture of one’s conscious predilections at the time of the test, but in ignoring the dynamic nature of the psyche they say nothing about the possibility of change.