Carl Gustave Jung worked out a theory of personality types (in the 1920s), where he identified four psychological functions, each with two possible forms. The functions are:

#1, inward or outward personal focus,
#2, how the self evaluates the outer world,
#3, what basis the self uses to make decisions,
#4, how the self deals with multiple possibilities.

The paired forms of each function are:

#1, introvert/extrovert,
#2, intuitive/sensorial,
#3, thinking/feeling,
#4, judging/perceptive (open-to-possibilities).

The eight elements from which sixteen personality types can be defined are:

Introvert (I):
An inward personal focus.

Extrovert (E):
An outward personal focus.

Intuitive (N):
Evaluate the external world by focusing on ideas.

Sensorial (S):
Evaluate the external world by focusing on things.

Thinking (T):
Basing decisions on thought (analysis).

Feeling (F):
Basing decisions on feeling (emotion).

Judging (J):
Seeking to close possibilities and capture the moment.

Perceptive (P):
Seeking to open the possibilities of the moment.

Using the letter symbols for each of the eight elements, one can list the sixteen types, (grouped by temperament) as follows:

(NF temperament): ENFJ, INFJ, ENFP, INFP.

(NT temperament): ENTJ, INTJ, ENTP, INTP.

(SJ temperament): ESTJ, ISTJ, ESFJ, ISFJ.

(SP temperament): ESTP, ESFP, ISTP, ISFP.

The sixteen types were used (in the 1950s) by Isabel Myers and Katheryn Briggs, who formulated the Myers-Briggs Type Indicator, a test for identifying an individual’s default pattern of action. By the 1980s, David Keirsey and Marilyn Bates had grouped the sixteen types into four temperaments (as above), and expounded on this in their book: Please Understand Me, Character & Temperament Types. Keirsey and Bates used the following temperament labels:

NF temperament: Apollonian
(seekers of fulfillment through metaphysical insights),

NT temperament: Promethean
(fulfilled by seeking power over nature through knowledge),

SJ temperament: Epimethean
(seeking fulfillment through duty, service and social structure),

SP temperament: Dionysian
(seeking fulfillment by the direct sensation of life through action).

My parenthetical characterizations (above) of K&B’s four temperaments are necessarily incomplete; read their book for their detailed intentions.

My chart shows that:

People have either a sensorial (S; hands-on) or intuitive (N; mind-based) manner of interacting with the world external to the self.

SPs and SJs have a sensorial (S) self-world interaction.

NTs and NFs have an intuitive (N) self-world interaction.

SPs aim to open the possibilities of the moment by focusing on things (sensation of the world); where the T-type variety use thought to decide how to act, and the F-type variety use emotion to decide how to act.

SJs aim to close possibilities and capture the moment by focusing on things (the nuts-and-bolts of “reality”); where the T-type variety use thought to decide how to act, and the F-type variety use emotion to decide how to act.

NTs are naturally instinctive analysts; the P-type variety use thoughtful analysis to expand the possibilities of the moment (options), while the J-type variety use thoughtful analysis to close off possibilities and capture the moment (finality).

NFs are naturally instinctive empaths; the P-type variety use intuitive emotion to expand the possibilities of the moment (options), while the J-type variety use intuitive emotion to close off possibilities and capture the moment (finality).

A set of secondary features, shown in the chart, are these:

SPs will extrovert (interact with others by talking about and showing) things and concrete details.

SJs will introvert (base their behavior on a hidden internalized mulling over of) things and concrete details.

P-type NTs will extrovert (interact with others by talking about and showing) their ideas.

J-type NTs will introvert (base their behavior on a hidden internalized mulling over of) their ideas.

P-type NFs will extrovert (interact with others by talking about and showing) their feelings.

J-type NFs will introvert (base their behavior on a hidden internalized mulling over of) their feelings.

The chart is my attempt to abstract all the above into one graphical image.

C. G. Jung did not linger too long with his personality type theory (the basis of all subsequent formalizations) because he knew that real people can mature with experience, and round out their personalities beyond the default patterns they were born with. Introverts (I) can learn how to make public addresses, Extroverts (E) can learn how to keep silent and listen to others, Sensorials (S) can learn how to be patient and listen to the elaboration of ideas and theories, Intuitives (N) can learn how to evaluate data and calculate specifics, Thinkers (T) can learn how to accept emotions, Emoters (F) can learn how to be logical, Judgmentals (J) can learn to be flexible, and Perceptives (P) can learn to arrive at useful conclusions. Jung believed that most people should be able to round out their psychological functioning by the age of 37.

So, the personality type model above is best taken as a rough guide of the general patterns of habitual individual behavior, rather than some robotic psychological horoscope.

Enjoy.