Harry Stack Sullivan, "was the founder and chief proponent of a branch of psychodynamic/psychoanalytic thinking called variously interpersonal psychiatry or interpersonal psychoanalysis." (p. 3)
Sullivan is often criticized for his "lack of concern for intrapsychic phenomena." However, Greenberg and Mitchell (1983) believe that the criticism is mistaken:
The belief that Sullivan's theory ignores intrapsychic phenomena is what one usually hears from psychoanalytic colleagues, indicating that it is deeply in the lore of the psychoanalytic community. Yet, as Greenberg and Mitchell (1983) state, the criticism that Sullivan favored interpersonal over intrapsychic phenomena is largely due to a misreading or lack of understanding of Sullivan. Regarding the so-called debate between interpersonal versus intrapsychic models, Sullivan pointed out that human experience is a dynamically unfolding interaction between interpersonal, environmental influences and the internal (i.e. intrapsychic) meaning system of self and other personifications which interpretatively modify one's perception and responses to these external experiences. (p. 7)
Sullivan's theory is to be described as an interpersonal theory of psychiatry.
Whereas great thinkers like Freud, Jung, and Kraepelin oriented their penetrating insights on the functioning of the individual, Sullivan offered a systematic conception of humankind in its social world or context. (p. 55)
It is not that Sullivan neglected the intra-psychic.
For Sullivan, that which is truly intra-psychic is purely private and essentially unknowable. Once a person discusses, or even anticipates discussing, an “internal” experience, it is no longer private or internal, but becomes an interpersonal event, affected by social forces. (p. 57)
A psychiatrist or indeed any observer interferes with her own observation and everything she observes is at least partially affected by her: other observer would see a different picture and no one is the true observer.
As Sullivan observed, everyone has his or her own conception of human living (i.e. our personal “theories of personality”) which is experienced and strongly held as intuitively correct. This deeply personal conception of “reality” is central in bringing coherence to the personal and non-personal world around us and to whom we are in that world.
Similar to Heisenberg's (1958) principle of indeterminacy (which, in sub-atomic physics, is where the measurement of a phenomenon with the same level of phenomenon alters the phenomena measured), the psychiatrist observer participates in and alters every interaction that he or she observes. Unlike Heisenberg's measurement electrons whose properties are well known, the properties of the psychiatrist are far more puzzling. (p.58)
Likewise, other persons around a person constitutes what the person is through interactions.
Sullivan's central definition and most distinguishing contribution is a revision of psychiatry as the science of interpersonal living,that personality could not be separated from the interpersonal world in which the person lives. The interpersonal theory is a significant critique and reworking of Freud's psychoanalytic approach and major departure from Kraepelin's descriptive psychiatry. (p.60)
Sullivan also takes a developmental approach. Of great interest is his distinction of prototaxic, parataxic, and syntaxic modes of experience.
The following is a summary of Sullivan's idea of epochs of development.
Sullivan defined infancy as the period from birth until the development of articulate speech. Childhood marks the appearance of the need for playmates, both adult and child, and is the first step in developing interpersonal communication through language. The juvenile era begins with the child's entrance into school and continues until the child finds a chum. Most importantly, it was the first developmental stage where family limitations and peculiarities were open to substantial modification. In pre-adolescence, the need for chumship, an intimate relationship with a compeer, a person of comparable age and status, is the central developmental event. Early adolescence begins with puberty and genital sexuality, the psychologically strong interest in members of opposite sex, and involves resolving the complex interplay between the dynamisms of lust, security, and intimacy. In late adolescence, the person begins to integrate the partially developed aspects of the personality into an age-appropriate, early adult identity. The task of adulthood is to establish a relationship of love with another person, someone who becomes as important as oneself. For Sullivan, this adult intimacy is “not the primary business of life, but is, perhaps the principal source of satisfactions in life” (1953:34). (p. 73)