What does “MBTI” mean?

Introduction

“MBTI” refers formally to the test developed by Myers and Briggs. I use the word informally for a theory that encompasses Jung’s initial work about cognitive functions (thinking, feeling, sensation, intuition) and attitudes (extraversion, introversion) with later additions, extensions and paraphrases (like Myers and Briggs).

History

A few landmarks:

1921: Jung publishes “Psychological Types”. It contains Chapter X that describes the four cognitive functions and their associations with the two attitudes.
1937: Van der Hoop publishes “Conscious orientation: a study of personality types in relation to neurosis and psychosis” based on Jung’s work. It is close to Jung.
1923 – 1930: Briggs reads Jung and publishes two articles about it.
1939 – 1945: Briggs and Myers design the test and start to collect results from subjects (like students). They are probably aware of Van der Hoop’s work at this time, as well as Jung.
1962 – 1975: Myers publishes the first manuals for the test. Briggs dies in 1968.
1980: Myers dies. Posthumously, her main book “Gifts Differing: Understanding Personality Type” is published. So far, the MBTI has not gained much popular attention.
1983: Harold Grant publishes “From Image to Likeness: A Jungian Path in the Gospel Journey” based on the work of Jung, Briggs and Myers where he introduces what is now called the “Grant stack”.

The theory and the test are pretty old but their fame is recent. Nowadays, the many ways it is taught to non-specialists are far from Jung, but also far from Myers and Briggs. Most popular internet websites are heavily simplified. Nevertheless, some people active on the internet do a good job at making it accessible, for example Alexis Kingsley, whose videos are above popular presentations.

Myers and Briggs

Jung introduced the auxiliary function shortly. He did not say anything about its attitude. But we have two hints:

He suggests several times that the attitude opposite to the conscious attitude rules over the unconscious of an individual. For example, an introverted thinker represses F into his unconscious, meaning that F will be ruled by extraversion.
The auxiliary function is essentially conscious

It is thus natural to assume that the auxiliary function has the same attitude as the dominant function (according to Jung). For example, an introverted thinker whose auxiliary function is N would “use” Ti and Ni. We can guess that Jung never inquired about it and assumed it by default. He never said anything explicit about it.

At some point, probably very early in their work, Briggs and Myers came to the assumption that the auxiliary function had the opposite attitude to the dominant function. It is very unclear if they justified it by quoting Jung. Most likely, they didn’t, but extrapolated things loosely related to it. In a way their reasoning could be summed up as “If compensation happens at the inferior level, it likely also shapes the auxiliary.”

They justified their choice by a personal idea. Paraphrasing it: “look at an introverted thinker. He cannot interact with the outer world using T (because T is introverted). What can you see about him? Not much of T. He must interact with another function and since the second in command is the auxiliary function, it must be it. If it is intuition, then this introverted thinker interacts with N, meaning he uses Ne”.

Whatever they read in Jung does not support this claim and the personal argument they use is not a real argument. Nobody really knows how they came to this. Was it a practical observation? Was it an intuition? Was it caused by misreading Jung? But in the end one thing matters: they happen to be right. It is, for me, their most important contribution to the theory. Why do I think they are right? I look at people.

Now, I don’t mean to praise Myers and Briggs as being smarter or more perceptive than Jung in general. Overall, their take about functions is not as good. It has the advantage to be more accessible but it is also less accurate.

Grant

Grant went further. Let’s imagine an introverted thinker with N as an auxiliary function. According to Jung:

F is heavily repressed and extraverted
N being pretty strong, S must thus be repressed, but not as much as F

The functions appear in this order of importance: Ti > N > S > Fe. Since Grant admitted the claim of Myers and Briggs about the auxiliary function, we have Ti > Ne > S > Fe. And finally, if we admit that opposite functions have opposite attitudes in a given individual, S would be introverted as opposed to N. The stack is then: Ti > Ne > Si > Fe. It goes the same for all types. We write this stack IEIE / EIEI for introverts and extraverts respectively. So far, the MBTI manual has not adopted the Grant stack and assumes the stack to be IEEE / EIII without insisting on it as a certainty.

Further than this, Grant assumed the existence of a “shadow” part of the stack, made of four next unconscious functions having reverse attitudes. In our INTP example, it would be Te > Ni > Se > Fi. The first four functions and the last four ones are called the “8 functions model”. Later, John Bebee associated archetypes names to each of them: hero, parent, trickster, daemon… and the “8 functions model” usually refers to his ideas. I’m not into it.

When talking of the “Grant stack”, people often refer to the first four functions only. It’s what I do. For the four first functions, my observations tend to confirm the Grant stack is correct.

What I call the MBTI

Finally, the name “MBTI” means for me: Jung’s theory + the four first functions of the Grant stack + various modern changes in the description of functions (but not all of them). It’s overall consensual. My approach is closer to Jung than Myers and Briggs in the sense:

Some references to Jung’s original work, none to Myers (but implicitly via mainstream ideas)
More focussed on combination of function/attitude: Te, Ti, Fe, Fi…
Staying away from interpretations of J/P as much as possible

But Jung is not the only author worth reading. Many persons write good things and the modern culture around the “MBTI”, including random individuals on the internet, brings valuable addition to Jung. For example, Jung saw F mainly as feeling and valuing, while the modern understanding has enriched it with values, interpersonal ethics, good/bad and narratives. Jung saw T as intellect in general (which made sense for the meaning of “intellect” in 1920), while the modern take has refined it.

Overall, if focussing only on serious authors like Jung or Van der Hoop, or even Myers, the understanding of the “MBTI” is good. While it is mainly rejected by academics, Jung and Van der Hoop constitute a substantial academic work. There is not such a wide gap between popular understanding and reality, provided we don’t go as far reading popular websites (16personalities, personalityjunkie…) too seriously. Moreover, some enthusiasts who are not especially scholars (Alexis Kingsley, Juan E Sandoval…) provide some good resources, accessible by a casual learner, helping to bridge the gap between Jung and practical meaning. Michael Pierce is not bad; I just dislike his way of rambling.

Compared to the Enneagram, the MBTI has a solid ground of textual references and rather clear explanations. For someone wanting to study it a bit seriously, it is less of a maze.