Exploring Type beyond the Four Letters

About the MBTI® Instrument 


Exploring Type beyond the Four Letters

The Dynamic Nature of Type

The 16 MBTI® types are not static labels; they are 16 unique and dynamic systems, that hold complex information about how each type accesses and uses the eight functions- in-attitude, or psychological types, created by Jung.

The Parts before the Whole

When most people are introduced to MBTI® type, they are introduced to the four letters that make up their MBTI® type code. This information, in and of itself, has proven so valuable to so many, that the MBTI® personality assessment remains the gold standard of type instruments. Quite often, however, people do not have the benefit of learning at a deeper level to grasp what their type really means; they miss the richness that MBTI® type has to offer. This richness is unveiled through what is termed, “Type Dynamics.”

The Principles of Type Dynamics

There are three overarching principles of Type Dynamics:
  • Each type accesses and develops the eight mental functions in a different hierarchical order; this order determines the nature of each type
  • Each type is different in its ability to maintain balance between extraversion and introversion and judging and perceiving
  • Type is a system of energetic movement between the mental functions

The Hierarchical Order of the Functions

Myers’ J-P dichotomy completed the structure for Jung’s psychological types; it provided a formula for identifying our dominant and auxiliary functions. The formula also established a preference order for use and development of the four basic functions within each of the 16 types, and the attitude in which each function appears within a type. In other words, Myers provided us with a theoretical order for how we prefer to use each of Jung’s functions – how we naturally distribute our energy between these eight mental functions to operate in the world. Although we use all eight, we will concentrate on the first four – keeping in mind that we can use and do use all eight.

The Dominant Function

The dominant (or leading) function is the first of the eight mental processes (Functions-in-Attitude) in the type hierarchy of each of the 16 types. It appears as one of two middle letters of the type code.
The dominant function is the mental process that guides the personality; the one that we habitually use more than the other seven mental functions. The dominant function provides the overall direction to the personality and is the way in which we most comfortably adapt to the world; we rely on it the most to guide us through life’s situations, especially during the first half of life.
We use our dominant function in our preferred world of Extraversion (the external world) or Introversion (the internal world):
  • Someone who prefers Extraversion will have one of the four extraverted functions as a dominant function. An Extraverted Type will put his or her best foot forward for the entire world to see.
  • A person with a preference for Introversion will have one of the four introverted functions as a dominant function. People will not necessarily be able to see the dominant function of an Introverted Type, because it is used internally.  Therefore, people with a preference for Introversion are often misunderstood.
We use all of our other functions (auxiliary, tertiary and inferior), “in service of” our dominant function; our other functions provide our dominant with alternative perspectives to guide us through the world.

The Auxiliary Function

The second function in the type code hierarchy is the auxiliary (or supporting) function. It is represented by the other middle letter in the type code. The auxiliary function guides the dominant function; it is the function we use the most after our dominant. The auxiliary also provides balance for the dominant in both function and attitude.

The Tertiary Function

The tertiary function is opposite the auxiliary on the same dichotomy; it is used in either the same OR the opposite attitude of the dominant function. The tertiary function does not appear in the four letters of the MBTI® type code.
Theoretically, our tertiary function is easier for us to access and use than our inferior function, but harder to access and use than our dominant and auxiliary. We use the tertiary function, like the auxiliary function, to help the dominant function navigate in a different direction.

The Inferior Function

The inferior function (also known as the fourth function) is opposite the dominant function on the same dichotomy and is in the opposite attitude of the dominant.
We have a harder time accessing, using and becoming comfortable with this function than we do with the other three mental processes in our type hierarchy. The inferior function can be the most problematic of the functions in our type code as it is inherently contradictory to the dominant function that is leading the personality. When we are stressed or tired, the inferior function is the one that is bound to “erupt,” causing us to become “out- of- sorts” or unlike ourselves, or “in the grip” (Naomi Quenk). The inferior function does, however, have its purpose, which is to provide us with an entirely different perspective than is afforded by our dominant function. The inferior function can teach us valuable life lessons, and is considered by Jungians to be the function that bridges the personality to the world of the unconscious.

The Principle of Balance

Myers extended Jung’s theory to incorporate the auxiliary function because she felt it was implied in Jung’s theory (download this PDF on Type Dynamics and Development). She interpreted Jung’s brief mention of a secondary function to mean that two Perceiving functions and two Judging functions cannot pair together; we all need a primary way to take in information (Perceive) and a primary way to evaluate that information (Judge); otherwise, we would always be either gathering information and never deciding, or making decisions based on no data. Thus:
  • A dominant Perceiving function(Sensing or Intuition)will have a Judging auxiliary function (Thinking or Feeling), and;
  • A dominant Judging function (Thinking or Feeling), will have a Perceiving auxiliary function (Sensing or Intuition).
Additionally, Myers, like Jung, noted that we must all be able to operate successfully, or adapt to, both the world outside of us (extraverted) and the world inside of us (introverted). It was important to identify an auxiliary function that is in the opposite attitude to our dominant function, otherwise, we would not be able to contribute to society, or have a way to be with ourselves. Thus:
  • An Introverted auxiliary function (Introverted Sensing, Intuition, Thinking or Feeling) will balance an Extraverted dominant function (Extraverted Thinking, Feeling, Sensing or Intuition), and;
  • An Extraverted auxiliary function (Extraverted Sensing, Intuition, Thinking or Feeling) will balance an Introverted dominant function (Introverted Sensing, Intuition, Thinking or Feeling).
The dominant and auxiliary functions are the most accessible, or conscious functions. In combination, they provide us with a way to gather information and make decisions in both the outer and inner worlds. It is this back and forth between the dominant and auxiliary functions – the movement in and out of our favorite mental processes – that create balance in the personality.

The Principle of Dynamic Movement between the Functions

The MBTI® four-letter code does not box us into using only the functions that appear in our code. (Download Type Dynamics – the Way Out of the “Box” PDF) Everyday life requires that we use our tertiary and inferior functions, as well as the other four mental functions that are not in our type code, even though we may not use them as well. Essentially, each of the 16 types is a dynamic system between the flow of psychic energy from mental process to mental process and from our conscious to our unconscious mind. In essence, type is personality in motion. Although we are at home with using our two favorite mental functions, we can, and do, move in and out of the mental functions that are required and appropriate for the situation.

Understanding Type Development

“The goal of type development… is not equal development and use of all of the functions, but rather the ability to use each mental process with some facility when it is appropriate.”Myers and Kirby, Introduction to Type Dynamics and Development
According to Jungian theory, we continue to grow and develop throughout the course of our lifetime. Our MBTI® type can be a compass for the path on our journey toward growth and development. All of us have strengths and weaknesses and quite often they are associated with the mental functions; those that are easy for us to use, and those which are harder to use because they remain more or less in our unconscious mind.
If we have the proper support from our environment to be who we are, we will naturally tend to develop our dominant function first, and then our auxiliary function. We don’t ever change our innate type, but as we move through life, we will continue to grow and develop by learning to use and become more comfortable with our less favorite mental processes. Myers’ hierarchy of functions provides us with a way to understand our innate or natural path for growth and development; we develop each of the functions, starting with our dominant, throughout life.
The more we are aware of our unique type pattern for growth, the more we gain valuable skills that allow us to appropriately use our strengths as well as develop our weak areas.