Jung’s typology, or model of psychological types, combined his 20 years of clinical experience with his broad study of historical and cross-cultural material on the subject. Psychological types, for Jung, refers to types of consciousness rather than types of people. Jung (1921) described psychological types as developed orientations of the ego in its relationships to inner and outer reality. Typology includes two basic attitudes, introversion and extraversion, and four basic functions: thinking, feeling, sensation, and intuition. Introversion and extraversion are terms that describe the process and direction of movement of psychic energy in the relationship between ego/subject and other/object.
Types are psychological modes of adaptation that emerge from an innate psychological core. Introversion is characterized by the general movement of psychic energy from object/other to the ego and extraversion describes the general propensity for energy to be moving from ego to object/other. Jung used the terms as adjectives, such as in extraverted thinking, to demonstrate their descriptive and dependent quality. He argued that all people use both processes; however, they use them differently and to differing degrees (Jung, 1921). Beebe (2006) describes introversion as a movement away from the external object/other/experience to the most related inner idea/meaning/archetype that matches with it. Extraversion, on the other hand, is a tendency to merge, adjust to, or identify with the object. Sharp (1987) summarizes introversion as being associated with hesitancy, reflection, internal/subjective motivation, and a shrinking away from the object, whereas in extraversion, the subject is characterized by an outgoingness that adapts easily to situations and is motivated by external factors.
The four functions within Jung’s typology are the capacities of the ego to orient itself to reality: thinking is the process of defining reality; feeling is the assignation of value; sensation is the registering of reality as real; and intuition is a divination of implication and possibility. Jung described thinking and feeling as rational and discriminating functions of judgment, with thinking being the faculty of logical discrimination and feeling the faculty of discerning likes and dislikes. Both thinking and feeling are “based on a reflective, linear process that coalesces into a particular judgment” (Sharp, 1987, p. 16). The evaluative quality of these functions is what groups them as rational. Sensation and intuition, on the other hand, are irrational in the sense that they are beyond or outside of reason; they are more empirical or perceptive ways of knowing. Sensation is the faculty of immediately perceiving the outside world, whereas intuition deals with past and future, hunches and prospects.
As processes for relating to experience, every individual exercises the entire range of typological orientations, albeit in varying degrees of development. Jung theorized that the processes of individuation, particularly in analysis, parallel the differentiation of the psychological types. Differentiation in this case is the process by which each function becomes available to consciousness for application in the appropriate circumstance. Invariably, however, development proceeds along distinctive pathways and one function is generally more developed than the others. The most utilized and developed function of an individual ego is called the superior function and the least developed the inferior function.
Although Jung categorically argued in favour of an essentialist view of human psychology, he also appreciated the effects of environment and context on development. In childhood, he theorized, an individual’s innate superior function is generally supported as a gift or strength of the individual, which further promotes its development. The inferior function, by contrast, is most closely related to the unconscious, undadapted, underutilized, and degenerated side of the personality. In the case that the development of an individual’s essential typology is suppressed, either due to family or cultural environment, the individual is considered a distorted type. In general, Jung’s model assumes an imbalance and promotes a developmental perspective in which the inferior function is gradually integrated into the psyche as a whole.
The inferior function, as the despised or unadapted aspect of the psyche, often holds the key to healing and wholeness. Von Franz (1971), in her extensive research in the area, argues that the inferior function “always makes a bridge to the unconscious” (p. 10). It is important to note that the unconscious is not necessarily a quality of interiority, as introverted attitudes will often display unconsciousness in their relationship to external reality. The inferior function is slow, hard to work on, touchy, tyrannical, charged with affect, covered up, magical, primitive, archaic, and generally bothersome to consciousness. On the other hand, the inferior function provides the possibility of reinvigorating the psyche when the one-sided dominant superior becomes weary of the world toward the middle of life. The ecstatic state, the opportunity for wholeness and a relationship to the infinite all align with the inferior function. Jung’s typology describes the inherent qualities of engaging available to all humans and in this sense are modes of differently apprehending and engaging with reality.