Jung’s Psychological Types: Introversion, Extraversion and the Four Functions

Why Jung wrote Psychological Types

Jung wrote the book in the years after his break with Freud, partly to understand why intelligent people could look at the same facts and see them so differently. He noticed that Freud explained neurosis through a person’s relationships with others, while Alfred Adler explained it through the person’s own striving for power, and he took this as a difference of temperament: one outward looking, one inward looking.

Much of the book is historical. Jung traces the opposition of the two attitudes through the early Christian theologians, medieval debates, Friedrich Schiller, Friedrich Nietzsche’s Apollonian and Dionysian, and William James’s tender-minded and tough-minded, before setting out his own system in the final chapters.

Introversion and extraversion

For Jung introversion and extraversion describe the direction in which psychic energy flows. The extravert is oriented primarily toward the object, the outer world of people, things and events. The introvert is oriented primarily toward the subject, toward inner reactions, ideas and images.

This is not the same as shyness and sociability. An introvert can be socially skilled, and an extravert can be quiet; the question is where each finds orientation and energy. Jung also stressed that everyone has both attitudes. One is usually dominant and conscious, while the other works in the background and in the unconscious. He spelled the word extravert, and this spelling is still used in Jungian writing.

The four functions

Next to the two attitudes, Jung described four basic functions of consciousness. He summarized them roughly as follows: sensation tells us that something exists, thinking tells us what it is, feeling tells us what it is worth, and intuition tells us where it comes from and where it is going.

Thinking

Orientation through logic and concepts; judging by truth and consistency.

Feeling

Orientation through values; judging by what is acceptable, important or right. For Jung feeling is a rational judgment of value, not the same as emotion.

Sensation

Perception through the senses of what is concretely present.

Intuition

Perception of possibilities, connections and hidden meanings, often by way of the unconscious.

Jung called thinking and feeling rational or judging functions, and sensation and intuition irrational or perceiving functions, meaning that they register what is given rather than evaluate it. Each pair forms opposites: a person strong in thinking tends to be less developed in feeling, and one strong in sensation less developed in intuition.

The eight types and the inferior function

Combining the two attitudes with the four functions gives Jung’s eight types: extraverted thinking, introverted thinking, extraverted feeling, introverted feeling, extraverted sensation, introverted sensation, extraverted intuition and introverted intuition. The function a person relies on most is the dominant function; a second, supporting one is the auxiliary function.

The function opposite the dominant one is the inferior function. It is the least developed, the slowest and the most emotional, and it is closest to the unconscious. A strongly thinking type may be clumsy and easily overwhelmed in matters of feeling. For Jung the inferior function is a source of embarrassment, but also the door through which the unconscious and new life enter. Marie-Louise von Franz developed this idea in her lectures on the inferior function (1971).

Jung and the Myers Briggs Type Indicator

The best known descendant of Jung’s typology is the Myers Briggs Type Indicator (MBTI), developed by Katharine Cook Briggs and her daughter Isabel Briggs Myers from the 1940s and first published by the Educational Testing Service in 1962. It added a fourth dimension, judging versus perceiving, and produces sixteen four-letter types such as INFJ or ESTP.

The MBTI is widely used in business and coaching, but it is criticized by research psychologists. Studies have found that many people receive a different type when they retake the test, and that sorting people into either-or categories ignores the fact that most traits are distributed on a continuum. Jung himself warned against using his types to put people into boxes; for him they were a tool for orientation, not a label.

Extraversion, on the other hand, has survived in scientific personality psychology. It is one of the Big Five personality traits, the most widely researched model today, where it is measured as a continuous dimension rather than a type.

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