Personality Type Theory & In-Depth Overview


Personality preferences are similar to left- or right-handedness; individuals are born with and develop certain preferred ways of thinking and acting. 

Fundamental to the MBTI is the theory of psychological type as originally developed by C. G. Jung, who proposed the existence of two dichotomous pairs of cognitive functions. 

• The "Rational" (judging) functions: Thinking and Feeling
• The "Irrational" (perceiving) functions: Sensing and Intuition

The terms "rational" and "irrational" are not value judgements and as such do not imply "good" and "bad" or "logical" vs. "illogical." They are neutral terms meant to capture the nature of the functions. 

Jung suggested that these functions are expressed in either an "Introverted" or "Extraverted" form. From Jung's original concepts, Briggs and Myers developed their own theory of psychological type, on which the MBTI® is based.

Type Theory

In the same way that writing with the left hand is hard work for a right-hander, so people tend to find using their opposite psychological preferences more difficult, even if they can become more proficient (and therefore behaviorally flexible) with practice and development.

The MBTI® sorts some of these psychological differences into four opposite pairs, or "dichotomies," the various combinations of which result in 16 possible psychological types. None of these types is "better" or "worse"; but Briggs and Myers recognized that everyone naturally prefers one overall combination of type differences. 

The 4 dichotomies are:

• Extraversion/Introversion (the E-I Scale)
• Sensing/iNtuition (the S-N Scale)
• Thinking/Feeling (the T-F Scale)
• Judging/Perceiving (the J-P Scale)

The various combinations of the above types result in 16 overall "Types." For example:

• ESTJ -  Extraversion, Sensing, Thinking, 
• INFP -  Introversion, iNtuition, Feeling, Perceiving

...And so on for all 16 possible type combinations.

It is important to understand that the terms used for each dichotomy have specific technical meanings relating to the MBTI® that differ from their everyday usage. For example, people with a preference for Judging over Perceiving are not necessarily more "judgmental" or less "perceptive".

Nor does the MBTI instrument measure aptitude; it simply indicates a preference for one style over another. Someone reporting a preference for Extraversion over Introversion cannot be correctly described as "more extraverted."

Since the MBTI® is based on type theory, it should not be confused with tests that measure traits, in which "quantities" are measured. Though the MBTI does return a "score" (the Preference Clarity Index or PCI), the number is only meaningful inasmuch as it tells us the likelihood that the preference is accurate, it does NOT tell the degree of the preference. In other words, the direction of the preference (for example, E vs. I) is more important than the degree of the preference (for example, clear vs. slight).

The 4 Scales: E-I, S-N, T-F, and J-P

The "Attitudes:" Extraversion (E) / Introversion (I)

The preferences for Extraversion (thus spelled in Myers-Briggs jargon) and Introversion are referred to as "attitudes." Briggs and Myers recognized that each of the functions (Sensing, iNtuition, Thinking and Feeling) are sometimes focused in the external world of action, people and things (extraverted attitude) or the internal world of ideas and reflection (introverted attitude). The Myers-Briggs Type Indicator sorts for an overall preference for one or the other of these.

People with a preference for Extraversion generally draw energy from the outside world; they tend to act, then reflect, then act further. Extraverts desire breadth of experience and are action-oriented, If they are inactive, their level of energy and motivation tends to decline. 

Conversely, those whose preference is Introversion become energized from their internal world. The often prefer to reflect, then act, then reflect again. Introverts desire depth of experience. People with Introversion preferences need time out to reflect in order to rebuild energy. 

It is very very important to understand that a preference for E or I does not imply that a person does not use the other. Everyone uses both attitudes and the theory of "Type Dynamics" helps to explain when and how people do use their less preferred attitude.

The "Functions:" Sensing (S) / iNtuition (N) and Thinking (T) / Feeling (F)

Jung identified two pairs of psychological functions: the two Perceiving functions, Sensing and iNtuition (thus spelled in Myers-Briggs jargon to distinguish it from Introversion); and the two Judging functions, Thinking and Feeling. Although each person uses one of these four functions more dominantly and proficiently than the other three, all four functions are used at different times depending on the circumstances.

Sensing and iNtuition are the information-gathering (Perceiving) functions. They describe how new information is understood and interpreted. 

Individuals who prefer Sensing are more likely to trust information that is in the present, tangible and concrete, that is, information that can be understood by the five senses. They prefer to look for details and facts. For them, meaning is in the data, in observable experiences in the here and now. They may often extrapolate from observable data out to the big picture.

In contrast, those who prefer iNtuition tend to trust information that is more abstract or theoretical, that can be associated with other information (either remembered or discovered by seeking a wider context or pattern). They may be more interested in future possibilities. They tend to trust flashes of insight from the unconscious mind. Those preferring iNtuition may often interpolate from theories and patterns to practical applications. 

Thinking and Feeling are the decision-making (Judging) functions. The Thinking and Feeling functions are both used to make decisions, based on data received from their information-gathering functions (Sensing or iNtuition). 

Those who prefer Feeling tend to come to decisions by associating or empathizing with the situation, looking at it "from the inside" and weighing the situation to achieve the greatest harmony, consensus and fit, considering their needs or values. 

Those who prefer Thinking tend to decide things from a more detached standpoint, measuring the decision by what seems reasonable, logical, causal, consistent and matching a given set of rules.

People with a Thinking preference do not necessarily "think better" than their Feeling counterparts; both are considered rational decision-making processes (in any case, the MBTI assessment is a measure of preference, not ability). Similarly, those with a Feeling preference do not necessarily have "better" command of their emotions than their Thinking counterparts.

Although people use all four cognitive functions (Sensing, iNtuition, Thinking and Feeling), one function is generally used in a more conscious and confident way. This dominant function is supported by the secondary (auxiliary) function, and to a lesser degree the tertiary function. The fourth and least conscious function is always the opposite of the dominant function. Jung and Myers called this the inferior, or shadow, function.

The four functions operate in conjunction with the Attitudes (Extraversion and Introversion). Each function is used in either an extraverted or introverted way. A person whose dominant function is extraverted intuition, for example, uses intuition very differently from someone whose dominant function is introverted intuition.

"Orientation to the Outer World:" Judging (J) / Perception (P)

Myers and Briggs added a fourth scale (J-P) to Jung's typological model by identifying that people also have a preference for using either the Perceiving function (Sensing or iNtuition) or the Judging function (Thinking or Feeling) when relating to the outside world (Extraversion).

Those who prefer the Judging functions (Thinking or Feeling) prefer the decision process and are classified as "J", while those who prefer the information-gathering process are said to have a preference for P (Perceiving) and are sorted as "P." According to Myers, Judging types prefer to "have matters settled" while Perceiving types may like to "keep their options open." The J-P scale gives us the fourth and final letter of the MBTI type.

A person's Orientation to the Outer World (their preference for J or P) also determines how their functions are oriented. For example, types with a preference for Judging show the outer world their preferred Judging function (Thinking or Feeling) and tend to introvert their Perceiving function (Sensing or iNtuition.) 

An example of this is a person with a preference for Thinking (T) and Judging (J) - in other words "TJ Types" might appear to the world as a logical, decision-making doer. While a person with a preference for Feeling (F) and Judging (J) might appear to the world as an empathetic doer. 

In contrast, a person with a preference for Perceiving, tends to show the outer world their Perceiving (information-gathering) function. For example someone with a preference for Sensing and Perceiving - an "SP type" - might appear to the world as someone who pursues new sensory experiences. In contrast, a person with a preference for iNtuition and Perceiving - an "NP type" might be someone who likes to develop and impart theories and ideas. 

[There is far more to the theory of the dynamics and it extends far beyond the scope of what we can explain and summarize here. If you are interested in learning more, we suggest reading the MBTI Manual, 3rd Edition.]

Whole type

As you may have noticed from the above explanations, the expression of a person's psychological type is more than the sum of the four individual preferences, because of the way in which the preferences interact through type dynamics and type development.

If you're interested in seeing brief descriptions of each type, click here

Format and administration of the MBTI

The current North American English version of the MBTI® includes 93 forced-choice questions. Forced-choice means that the individual must choose only one of two possible answers to each question. 

Choices are not literal opposites but rather "psychological opposites" chosen to appeal to the appropriate type. For example, to sort along the E-I scale, the opposite of "outgoing" would not be "shy," rather it would be "reflective" because that word would likely appeal to someone whose attitude reflects a preference for Introversion. Furthermore, participants may skip questions if they feel they are unable to choose.

Using psychometric techniques, such as item response theory, the MBTI® will then be scored to attempt to identify the preference, and clarity of preference, in each dichotomy. 

Before giving the results of the MBTI®, qualified administrators help their subject conduct a self-assessment of type. That self-assessment, together with the instrument, is used for a subject to determine their own "best-fit type." The best fit type is not always what the MBTI® indicates and it is important for people to understand that they are the only ones who can confirm their type!


Important considerations when administering and interpreting the MBTI® are:

Type not trait: The MBTI® sorts for type; it does not indicate the strength of ability. For example, the indicator may show your preference for thinking as a judging function, but not your ability to think! Type preferences are polar opposites: a precept of MBTI is that you fundamentally prefer one thing over the other, not a bit of both.

Self-determination: You are considered the best judge of your own type! While the MBTI questionnaire provides a Reported Type, this is considered only an indication of your probable overall Type. This is why we must go through the best-fit process described above. 

It's ALL good: No preference or type is considered "better" or "worse" than another - they are all valuable and necessary. If you find yourself "uncomfortable" or wanting to change your type, this may be an indication that A) you need to explore other types to identify a better fit, B) maybe that there are social or environmental pressures that are inhibiting your natural type or C) you need to keep in mind that types indicate only a preference, not ability, skill or worth. A qualified administrator may help you work through the self-identification process. 

Voluntary: It is considered unethical to compel anyone to take the Myers-Briggs Type Indicator. It should always be taken voluntarily - even (especially!) in the workplace.

Confidentiality: The result of the MBTI and best fit type are confidential between you and the administrator and not for disclosure (even to your boss or HR department) without your explicit permission.

Not for hiring, promoting, screening or selecting: Because the MBTI measures preferences instead of aptitude - and because there are no right or wrong types - it is not appropriate for purposes of employment selection. SSI tables (Self-Selection Index Tables) show us that all types can be successful at all levels in all professions. 

Importance of proper feedback: Individuals should always be given detailed feedback from a trained administrator and complete a Best-Fit exercise to check their Reported Type. 

Types in the General Population

click image to enlarge

Above are the estimated percentages of the 16 types in the American population.

It should be noted that because some types are more likely to take the MBTI than others (such as the INFP), there is an element of sampling error. For this reason, CAPT has provided ranges within which the actual percentages probably lie.

Type Dynamics & Development

The interaction of the various preferences is known as type dynamics, and it explains which a preference for any of the functions will manifest differently depending on the combination of letters. For example, an ENTP type will likely differ from an ENTJ in more ways than just a preference for P over J.

In addition, the unique type dynamics for each type will also influence when and how each preference is developed. 

Myers and Briggs asserted that for each of the 16 four-preference types, one function is the most dominant and is likely to be evident earliest in life. A secondary or Auxiliary Function typically becomes more evident (differentiated) during teenage years and provides balance to the Dominant. In normal development individuals tend to become more fluent with a third or Tertiary function during mid life, while the fourth Inferior function remains least consciously developed. 

The sequence of differentiation of Dominant, Auxiliary and Tertiary and Inferior Functions through life is termed type development. This is an idealized sequence which may be disrupted by major life events or social/environmental pressures.

The Inferior Funition is often considered to be more associated with the unconscious, being most evident in situations such as high stress (sometimes referred to as being "in the grip" of the inferior function).

This table shows all 16 types, including the Dominant (underlined) Function for each type, and a subscript showing in which direction that Dominant Function is oriented, whether outward (e) or inward (i). 

click the table to enlarge and for more detail

One interesting thing to note (especially if you're trying to interact and communicate better with other types) is how different types may appear to the outside world. For example, keep in mind that since an Extravert's Dominant Function is extraverted, we essentially "meet" their dominant function first, whereas because an Introvert introverts their Dominant Function, the outside world first meets their Auxiliary Function! Makes you think twice before you jump to conclusions upon meeting someone...


Here are some examples to clarify type dynamics and development further. Taking an ESTJ:

• Extraverted function is a Judging function (T-F)

• Extraverted function is dominant because of overall E preference

• Dominant function is extraverted Thinking (Te)

• Auxiliary function will be introverted Sensing (Si)

• Tertiary function is iNtuition (N)

• Inferior function is introverted Feeling (Fi)

The way this might play out is that the ESTJ's dominant tendency to order the environment, might lead them to set clear boundaries, to clarify roles and timetables and to direct the activities around them. Since their auxiliary function is introverted sensing, they will likely use memories of past experiences in an ordered and systematic way to help organize themselves and others to make decisions and get things done. 

ESTJs, for instance, may enjoy planning trips or work plans to achieve goals. ESTJs tend to be great at managing their time and channeling their energies productively. They will engage all the resources at their disposal to achieve their goals. 

Under prolonged stress or sudden trauma, ESTJs may fall into "the grip" of their inferior function, Introverted Feeling. Though the ESTJ can seem insensitive to the feelings of others in their normal activities, under tremendous stress, they can suddenly express feelings of being unappreciated or wounded by insensitivity.

Now lets take a look at the ESTJ's opposite Type, INFP:

• Extraverted function is Intuition function

• Introverted function is therefore Feeling, and it is Dominant (because of I preference)

• Auxiliary function is Extraverted iNtuition (Ne)

• Tertiary function is Sensing (S)

• Inferior function is Extraverted Thinking (Te)

The interplay between the dominant function of Introverted Feeling and the auxiliary Extraverted iNtuition means that INFPs tend to build a rich internal framework of values that, due to their Extraverted Feeling function, are often related to humanitarian and empathic ends, such as championing human rights.

They often devote themselves behind the scenes to causes such as civil rights or saving the environment. Due to their preference for Introversion, they may tend to avoid the limelight and maintain a reserved posture. And because they have a preference for the Perceiving (P) function (in this case, iNtuition) they have a rich internal world of ideas and may sometimes resist closing the door on them in making decisions. 

That said, INFPs tend to have strong ideals and strive to live up to them. When not under stress, the INFP usually radiates a pleasant and warm demeanor; under extreme stress, they can suddenly become rigid and directive, exerting their extraverted Thinking erratically.

Every type - and its opposite - is the expression of similar interactions among their preferences, which gives each type its unique "signature" that can be recognized.

Source: MBTI Manual, 3rd Edition

Michelle Villalobos is a personal branding expert, motivational and inspirational speaker and personal branding consultant based anywhere and everywhere.
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