The following is adapted from Gary Hartzler and Margaret Hartzler, Facets of Type: Activities to Develop the Type Preferences (Telos Publications, 2004) *Used with permission.
Carl Jung's model of the personality (he called it the psyche) incorporates a model that describes how we collect information and make decisions and what attitude we prefer to use as we interact with the world. In this typology he defines four functions, Sensing, Intuiting, Thinking, and Feeling, and two attitudes, Extraverting and Introverting. Sensing and Intuiting are the functions that relate to perception, collecting data/information. Thinking and Feeling are the functions related to evaluating and making decisions. Extraverting and Introverting describe where the psyche is focusing its energy.
Jung stated that people have an innate pull to develop two of the four functions and one of the attitudes more than the others; over one's lifetime all the functions and attitudes can be developed to some extent, but no one ever develops them all equally well.
When Isabel Myers and Katharine Briggs expanded Jung's theory, they added an attitude pair that they believed Jung implied in his writing but did not explicitly name. Briggs and Myers named this new attitude pair Judging and Perceiving.
In summary, there are four pairs of opposites:
One side of each of these four pairs of opposites will be innately preferred over the other. This means that people will be drawn to and choose to use those preferred functions and attitudes. The skills and characteristics of the non-preferences will not be as attractive. An analogy: A person who prefers chocolate ice cream, when given a choice between chocolate and vanilla, will generally choose chocolate, but in certain circumstances will choose vanilla.
Given that we each prefer one side of each of the four pairs of opposites, there are sixteen possible combinations of preferences. These are the sixteen psychological types that are indicated by the MBTI®instrument and other type instruments. The results of these instruments are four-letter codes called type codes.
You should always confirm your type code by a self-verification process in order to make sure it is the best-fit type for you. If you do not have access to an instrument, you can read definitions of the preferences and characteristics associated with each type and decide which type best describes you.
A caution: Too often when people get their four-letter code they begin to think of themselves as having four separate preferences. However, these four preferences interact in a dynamic pattern. Each type has a function, used in either an extraverted or introverted way, that is the superior (dominant) function, an auxiliary function (generally the next most used function), a tertiary function (occasionally used), and an inferior function (generally consciously used in very selected situations and often not used with conscious control). In other words, a type is more than the sum of its four preferences, so when making a selection of a best-fit type, you need to read type descriptions that outline the interaction of the preferences and explain the dynamics of the functions such as those provided in several of the books in the References on page 48.
For more information related to the dynamic patterns of the types, read Introduction to Type® and the Eight Jungian Functions: Applications for Work and Life, Introduction to Type® Dynamics and Development, or Understanding Yourself and Others®: An Introduction to the Personality Type Code
In 1985 Kathy and Peter Myers developed a team of type experts to consider what additional information could be gleaned from the various editions of the MBTI® instrument that had been published. A factor analysis was conducted and data collected on a new edition of the MBTI® instrument, called Form J, which included every question that had ever been asked on an MBTI® questionnaire.
The factor analysis identified five subscales for each of the four MBTI® scales. Each subscale was then described by defining the facets at each end of the subscale. These facets are, therefore, each associated with the corresponding end of the MBTI® scale in which the subscale fit.
For example, the Receiving Facet is one end of the Receiving/Initiating subscale, a subscale of the Introverting/Extraverting scale of the MBTI® instrument. See below for a table showing the four MBTI® scales, the twenty MBTI® Step II subscales, and the forty Facets.
When we are born we have very few mental skills available for use. The potential to use these skills exists in what Jung called the unconscious. In order to develop them we have to make them conscious. This means that we all have in our personality a variety of skills and abilities, but only if we put forth effort can we use these skills and abilities in a controlled, conscious way. A skill is considered "controlled" when we can use it in a way that the conscious part of our personality can call it up from unconscious or get it from the external world, process it, and decide whether or not to use the information provided. If we don't make a function conscious, it can be active but in the unconscious. If this function has enough energy in the unconscious it may begin to take over, acting without control of the conscious part of the personality. In these cases the results may be interpreted as "positive," but often they are perceived as "negative." (Positive and negative tend to be defined by our culture.) For example:
On the other hand, consciously using the mental skills associated with the functions and attitudes means that we can choose to use the appropriate skill to deal with any situation. This will make our lives more effective and fulfilling. Jung would have said we will be more whole, balanced people.
Environment and life circumstances also play a part in this developmental process. Usually people will develop more skills related to their "innate" preferences in the first twenty to thirty years of their lives and then seek balance by developing the opposite of their preferences for the rest of their lives. This means that most of us will believe we are better developed in the four preferences that are in our type code than we are in the four that are not in our code. However, generally we have certain skills related to our preferences that aren't as developed as much as we would like and we actually have a few skills related to our non-preferences that are developed.
While our type preferences are assumed to be innate, our development of the mental skills associated with our preferences and non-preferences will be influenced by our reaction to our environment and life circumstances. These circumstances can affect development of skills related to typology in many ways. For example:
In summary, this theory suggests that most of us will be more consciously able to use skills related to our preferences, especially if given environmental support, and that we have the capability of developing skills related to all eight preferences. Developing skills related to our non-preferences generally takes longer than developing skills related to our preferences. We need to allow our preferences to guide our personality, but we also need to develop enough of their opposites so we do not become one-sided. Balance is very important in this model of the personality. Thus if you use and trust Sensing as your primary information-gathering function, you still need to develop enough Intuiting so that the information this function provides can be used to cross-check and supplement the information gained from using the Sensing function.
In the following chapters, we will define each of the eight preferences as they are currently understood in the type community and define some mental skills that you can choose to focus on developing.