Psychological Types
Psychological Types is a book by Carl Jung that was originally published in German by Rascher Verlag in 1921, and translated into English in 1923, becoming volume 6 of The Collected Works of C. G. Jung. It is the baseline of many personality typology systems, particularly Myers Briggs.
In the book, Jung proposes four main functions of consciousness: two perceiving or non-rational functions, and two judging or rational functions. These functions are modified by two main attitude types: extraversion and introversion.
Jung proposes that the dominant function, along with the dominant attitude, characterizes consciousness, while its opposite is repressed and characterizes the unconscious. Based on this, the eight outstanding psychological types are: Extraverted sensation / Introverted sensation; Extraverted intuition / Introverted intuition; Extraverted thinking / Introverted thinking; and Extraverted feeling / Introverted feeling. Jung, as such, describes in detail the effects of tensions between the complexes associated with the dominant and inferior differentiating functions in highly and even extremely one-sided types.
Extensive detailed abstracts of each chapter are available online.
Historical context
Jung's interest in typology grew from his desire to reconcile the theories of Sigmund Freud and Alfred Adler, and to define how his own perspective differed from theirs. Jung wrote, "In attempting to answer this question, I came across the problem of types; for it is one's psychological type which from the outset determines and limits a person's judgment." He concluded that Freud's theory was extraverted and Adler's introverted. Jung became convinced that acrimony between the Adlerian and Freudian camps was due to this unrecognized existence of different fundamental psychological attitudes, which led Jung "to conceive the two controversial theories of neurosis as manifestations of a type-antagonism."Due to the multifarious nature of fantasy, the fantasies of both Adlerian and Freudian patients contained ample empirical evidence to reinforce the steadfast belief of each side in their respective theories.
Each side can demonstrate the truth embodied in its theory. However, it is only partial truth and not generally valid because it excludes the principle and truth embodied in the other.
Jung still used Adler's and Freud's theories, but in restricted circumstances.
Content
Chapter I
In this opening chapter, Jung traces the history of typology back to Gnosticism and early Christian theology. He suggests that the psychological differences between Platonism and Aristotelianism, as well as the theological disputes between early church fathers, were driven by type differences. Specifically, he contrasts Tertullian with Origen. Jung further analyzes the controversy over transubstantiation, proposing that the divergent views on whether the Eucharist was a symbolic or literal transformation arose from the fundamental psychological differences between introverted and extraverted attitudes toward the object.Chapter II
Jung devotes this chapter to Friedrich Schiller's Letters on the Aesthetic Education of Man. He analyzes Schiller's division of poets into the "naïve" and the "sentimental". Jung credits Schiller with recognizing the tension between the instincts of feeling and thinking and praises Schiller’s concept of the "play drive" as a transcendent function that unites the opposites through the creation of symbols.Chapter III
Here, Jung examines Friedrich Nietzsche's The Birth of Tragedy. He aligns the Apollonian impulse—associated with dream, measure, restraint, and the inner world of images—with introversion. Conversely, he aligns the Dionysian impulse—associated with intoxication, the breaking of boundaries, and the merging with the collective instinct—with extraversion. While acknowledging Nietzsche's insight, Jung critiques the philosopher for treating the extraverted release of the Dionysian as a purely aesthetic phenomenon rather than a psychological mechanism of release for the introvert.Chapter IV
This chapter focuses on the work of the 19th-century British surgeon Furneaux Jordan. Jung discusses Jordan's classification of character into "the less impassioned, active" type and "the more impassioned, reflective" type. Jung notes that Jordan’s observations were largely ignored because they contradicted the prevailing view that introversion was a form of pathology, whereas Jordan viewed the reflective nature as simply a different mode of functioning.Chapter V
By far the longest chapter in the book, this section is a detailed psychological analysis of Carl Spitteler's epic poem Prometheus and Epimetheus. Jung interprets the two brothers as personifications of the conflicting mechanisms within the human psyche. Prometheus represents the introvert who sacrifices the present for the future and the object for the inner image, while Epimetheus represents the extravert who is orientated by the object and the demands of the moment. Jung uses this analysis to explore the concept of the "soul-image", arguing that the repression of one function leads to its accumulation in the unconscious, eventually forcing a "enantiodromia," or conversion into the opposite.Chapters VI–IX
In these intermediate chapters, Jung surveys how the type problem appears in psychiatry, aesthetics, philosophy, and biography:Chapter VI : Jung reviews the work of Otto Gross, contrasting "deep" consciousness with "shallow" or broad consciousness.Chapter VII : Jung analyzes Wilhelm Worringer's Abstraction and Empathy. He correlates "empathy" with the extraverted willingness to merge with the object, and "abstraction" with the introverted need to withdraw from the object due to an underlying fear of its overwhelming influence.Chapter VIII : Jung discusses William James's distinction between "tender-minded" and "tough-minded" thinkers, equating them broadly with introversion and extraversion, respectively.Chapter IX : Jung briefly touches upon the subjectivity of biographers, noting that the psychological type of the biographer inevitably colors their interpretation of the subject's life.Chapter X: "General Description of the Types"
Attitude-types
Consciousness is directed by a tendency to form objective or subjective motives and ideas. Respectively, they are extraversion and introversion, giving rise to extraverts and introverts. The unconscious has its own attitude, opposite of consciousness.Function-types
Psychological functions are a form of mental activity that remain the same in principle under different conditions and cannot be reduced to each other. They can be rational and judging or irrational and perceiving.Thinking is the function which, in accordance with its logical laws, uses concepts to connect information. Feeling is a function that, according to its subjective value, accepts or rejects a concept. Sensation is the function that transmits physiological stimulus to conscious perception. Intuition is the function that transmits invisible, mental associations.
Just as consciousness is directed by an attitude, it is also directed by a function, giving rise to thinking types, feeling types, sensation types, and intuitive types. Likewise, the unconscious opposes the function-type with an opposing function. A thinking type's unconscious is characterized by feeling, and a sensation type's unconscious by intuition. The functions of the other group are more or less susceptible to conscious influence, that being their differentiation. For a thinking type, those are intuition and sensation; for a sensation type, those are thinking and feeling. The unconscious functions exist in an archaic state, and are often present in dreams and fantasies.
Psychological types
There are eight total combinations of the attitude-type and the function-type; the psychological types. They are categorised as extraverted rational types, extraverted irrational types, introverted rational types, and introverted irrational types.Extraverted rational types judge concepts and situations by what is generally considered to be rational. They suppress subjective reason and perception, and if repression occurs, they fall under their influence via the unconscious. Repressed sensation can express itself in the form of compulsive pleasure-seeking, and suppressed intuition in the form of compulsive suspicion of the unpleasant and evil. The extraverted feeling type dispenses judgement according to what is acceptable for and in tune with the environment. The extraverted thinking type judges according to the objective facts and valid ideas of the environment. Repressed subjective judging in an extraverted feeling type leads to a surfacing of undeveloped, negative ideas that deprecate what is valued, and an absolutist character for them. In an extraveted thinking type, selfish intentions surface, the person becomes overly sensitive and dogmatic, and loses sight of everything not relevant to the formula or cause.
Extraverted irrational types are guided simply by events as they happen, without constant judgement, and they base themselves on experiences. They suppress subjective perception and reason. If judging is repressed, they become calculating and the person never stays put long enough to reap the fruits of their work. Thinking takes the form of apparent sophistries or pedantry, and feeling of ruthlessness or puritanism. The extraverted sensation type is guided by experiences and is always on the lookout for new ones that excite the senses and are enjoyable. The extraverted intuitive type is guided by new ideas and possibilities in the making. Repressed subjective perception in an extraverted sensation type causes an unscrupulous search for stimulation, and unconscious intuition supplies wild suspicions, phobias, superstitions, and religious streaks. In an extraverted intuitive type, hypochondria and absurd bodily sensations surface, and compulsive attachments to certain sensations given by people.
Introverted rational types judge by their own principles. If objective judging is repressed, they become inflexible, navel-gazing, egotistical, and develop feelings of inferiority that they compensate for in the real world. The introverted thinking type is concerned with developing logical insights for its subjective ideas- an example is Kant. The introverted feeling type is also concerned with these ideas, but the person judges them with their feeling-values. Repressed objective judging in an introverted thinking type makes the person isolated, unsympathetic, sensitive to minor things that supposedly secretly concern the person, and aggressive in the face of criticism. In an introverted feeling type, the person becomes domineering, plotting, and forms many rivals.
Introverted irrational types are captivated by their subjective perception and inner world, chiefly as related to the collective unconscious. When objective perception is repressed, they become deluded and lose touch with reality. The introverted sensation type is guided by their perceptions that are merely suggested by the object in the moment, related to its aesthetic, becoming, and passing. This is seen when paintings of the same landscape differ not simply in ability. Intuition, on the other hand, receives from the sensation only the impetus to immediate activity; it peers behind the scenes, quickly perceiving the inner image that gave rise to the specific phenomenon, i.e. the attack of vertigo, in the present case. It sees the image of a tottering man pierced through the heart by an arrow. This image fascinates the intuitive activity; it is arrested by it, and seeks to explore every detail of it. It holds fast to the vision, observing with the liveliest interest how the picture changes, unfolds further, and finally fades. In this way introverted intuition perceives all the background processes of consciousness with almost the same distinctness as extraverted sensation senses outer objects. When objective perception is repressed in an introverted sensing type, compulsive thoughts of external malevolence occur. The introverted intuitive type becomes a hypochondriac, sensitive in the sense organs, and compulsively tied to particular people or objects.
Auxiliary functions
In reality, a type's principal function is often influenced by another function of secondary importance, despite its absolute sovereignty. Opposing functions, like thinking and feeling can be on the same level, but then they're relatively undeveloped. Sensation can give thinking practicality, intuition can give thinking speculations, feeling can give intuition feeling for choice of artistic images, thinking can give intuition a system for its vision, etc. The auxiliary can also allow the unconscious to be approached, by protecting the conscious standpoint from undue influence. A uniformly conscious state of functions is present among prehistoric peoples.Chapter XI: Definitions
This concluding chapter functions as a glossary, providing in-depth definitions for over fifty key concepts used throughout the book and Jung's wider psychology. It serves to clarify the specific meanings Jung assigns to terms that are often used loosely in common language. Significant definitions include:Idea: An image that is derived from the collective unconscious rather than personal experience.Introversion/Extraversion: Defined strictly as the direction of libido inward toward the subject or outward toward the object.Soul : Distinguished from the "Soul-image" and the Persona.Self: Defined as the center of the total personality, distinct from the Ego, which is the center of the conscious mind only.Symbol: Described as the best possible expression for a complex fact not yet clearly grasped by consciousness, acting as a machine to transform energy.Neuropsychological and Empirical Validation of Jung's Typology
1. Experimental Origins and Word AssociationJung's typological model was fundamentally rooted in his early experimental research at the Burghölzli Psychiatric Hospital. Using the Word Association Test, Jung provided some of the first quantitative data on the unconscious. He observed that "complexes" caused measurable delays in reaction times and physiological disturbances. Crucially, Jung identified that individuals exhibited consistent "attitudinal styles" in their responses: some were habitually oriented toward the objective stimulus, while others were consistently diverted by internal, subjective associations .
2. The Biological Axis of Arousal and Dopamine
Modern neurobiology has validated Jung's "direction of libido" through the study of cortical arousal and neurotransmitter sensitivity.
Ascending Reticular Activating System : Building on the Eysenckian model, research confirms that introverts possess a higher baseline of cortical arousal. This physiological state makes them more sensitive to sensory input, leading to a centripetal withdrawal to avoid overstimulation—a direct parallel to Jung’s "subjective protection".
Dopaminergic Reward System: Studies by Depue and Collins demonstrate that extraverts exhibit higher sensitivity in the mesolimbic dopamine system. Their brains show increased activation in the ventral striatum when processing external rewards, validating Jung's theory of the "centrifugal" flow of energy toward the object.
3. Regional Brain Mapping of Cognitive Functions
Advancements in fMRI and EEG have allowed for the mapping of Jung's four functions to specific neural architectures:
Thinking vs. Feeling : The "Rational" axis corresponds to the distinction between the dorsolateral prefrontal cortex and the ventromedial prefrontal cortex / amygdala. Research in neuroethics by Joshua Greene confirms that the brain utilizes these distinct "circuits" for impersonal logic versus value-based decision making.
Sensation vs. Intuition : The "Irrational" axis relates to sensory gating and holistic processing. Sensation is linked to the parietal lobes and primary sensory cortices. Intuition correlates with the Default Mode Network and high-speed pattern recognition across distant brain regions, often involving the right hemisphere's capacity for non-linear synthesis.
4. Longitudinal Stability and Genetics
The "type" as a stable biological category is supported by the work of Jerome Kagan, whose longitudinal studies on infants showed that "high-reactive" temperaments and "low-reactive" temperaments are visible as early as four months of age and remain stable through adulthood. Genetic studies have identified a heritability factor for these orientations ranging from 39% to 58%, suggesting that Jungian types are innate biological specializations rather than acquired behaviors.
Conceptual and Physiological Divergence: Types vs. Traits
The distinction between Jungian Type Theory and modern Trait Theory is a subject of significant neuropsychological debate. While trait models categorize personality based on lexical frequency and social behavior, Jung’s typology focuses on the underlying cognitive architecture and the movement of psychic energy.1. Behavioral "Output" vs. Biological "Engine"
Critics of the Big Five, such as Jack Block, have argued that lexical models only describe the "surface" of personality—how an individual is perceived by others—without explaining the biological "why". Physiological research suggests that an individual may score high in "Extraversion" on a Big Five test due to social skills, while their brain continues to operate on a "high-reactive" biological baseline. Jungian theory accounts for this through the concept of persona and compensation, whereas trait models often misidentify such individuals as "ambiverts."
2. The Dopaminergic Fallacy in Trait Models
Neurobiological research by Richard Depue reveals a fundamental flaw in how trait models aggregate behaviors. Big Five "Extraversion" often blends sociability with agency.
Physiologically, Jungian extraversion correlates with the mesolimbic dopamine system's sensitivity to external rewards.
In contrast, sociability is governed by distinct opiatergic systems related to bonding.
As a result, a Jungian extravert may be socially withdrawn yet remains biologically extraverted due to a high dopaminergic response to non-social objective goals, a distinction that trait-based models fail to capture.
3. Functional Specialization vs. Linear Scales
EEG research by Dario Nardi has demonstrated that the "middle of the scale" in behavioral tests often masks radically different brain patterns. Individuals labeled as "ambiverts" or "moderate thinkers" in trait models often show high-intensity activation in specific, divergent brain regions rather than a "balanced" or "average" brain state. This supports Jung’s categorical view that the brain develops habitual neural pathways rather than operating on a universal, linear continuum.
4. Neuroplasticity and the Stability of the "Core" Type
While trait models suggest that personality dimensions can shift significantly with age, neurophysiological evidence from Jerome Kagan suggests that the underlying amygdala reactivity remains remarkably stable throughout the lifespan. Individuals may acquire "extraverted" social behaviors, but fMRI data shows that the metabolic cost of processing stimuli remains consistent with their innate Jungian orientation.
Neurobiology of Intuition and the Default Mode Network
In Jungian typology, Intuition is described as a perceptive function that operates via the unconscious, focusing on patterns, possibilities, and holistic syntheses rather than concrete sensory data. Modern neuroscience correlates this process with the activity of the Default Mode Network —a large-scale brain network involving the medial prefrontal cortex, posterior cingulate cortex, and angular gyrus.
Holistic Pattern Recognition: Unlike the task-positive networks used in "Sensation", the DMN is highly active during internally directed thought and "mentalizing." Research suggests that individuals with a dominant Intuitive function exhibit higher connectivity within the DMN, allowing the brain to facilitate rapid, non-linear cross-talk between distant cortical regions. This physiological "leaping" across neural nodes mirrors Jung's description of intuition as a sudden, holistic realization that bypasses linear logical steps.
Divergent Thinking and the Right Hemisphere: EEG studies by Dario Nardi show that Intuitive types frequently enter a "zen-like" flow state where the entire neocortex reaches a high level of synchronous oscillations. This state is associated with the integration of information from the right hemisphere's associative areas, which are capable of processing metaphors and global patterns that the more localized "Sensation" circuits tend to filter out.
The Sensation-Intuition Trade-off: Neurophysiological evidence supports Jung’s view of these functions as mutually exclusive in their moment-to-peak activation. High activity in the Sensation-related parietal circuits typically requires the suppression of the DMN. This provides a biological basis for Jung's theory of the "inferior function," where the dominance of one perceptive mode physiologically inhibits the other