Bowen family systems theory grew from an effort to bring psychiatry and behavioral science more in line with the practice of the "hard sciences," especially biological science. Bowen's new approach, originating in the 1950's, involved considering the family the key unit in human functioning; and viewing behavior as a systems phenomenon rather than a matter of simple cause and effect. Systems had to do with seeing the larger picture and the reciprocal relationships among component parts. From this perspective, individual human functioning could be seen in relationship to forces beyond the individual. Bowen articulated how individual action emanated both from qualities of the individual and from the ongoing flow of forces in the social and physical environment. By maintaining a systems focus, Bowen illustrated the limitations of human perception and illuminated the ways in which perception is influenced. Bowen theory permits one to view the human being as part of the larger world that has evolved from other forms of life. It helps expand beyond the limits of human introspection and opens the understanding of humans to the advances of biology, ecology and the other sciences.
Key tenets of Bowen theory are as follows:
--- Variation in human functioning is significantly influenced by three key social/emotional variables. These are differentiation of self, stress, and effective contact with important others, especially the multi-generational family.
--- Differentiation of self is the quality of individuals, families, and groups that is associated with maturity and successful functioning in varying degrees.
--- Differentiation of self has to do with the capacity to separate thinking from emotion and to maintain individual prerogative in the face of social and relationship influences.
--- Levels of differentiation of self are transmitted across generations. Marriage tends to pair individuals at similar levels of differentiation and offspring tend to adopt this level, though with some variation among siblings.
--- Human difficulties emanate from a combination of environmental stressors, lower differentiation of self, and loss of contact with the multi-generational family. These difficulties manifest as physical illness, emotional symptoms, social dysfunction, or a combination of the above. Emotional symptoms take the forms of marital distance, marital conflict, under-functioning in one or both spouses, and under-functioning in one or several children. Families vary in their degree of vulnerability to these difficulties and in the ways that they characteristically manifest such duress.
--- All behavior is influenced by one's relationship network. Relationships between any two individuals tend to draw others in, so as to create a relationship network. Bowen called this phenomenon triangling. The ability to separate relationships from one another contributes to the ability to successfully problem-solve, both for oneself and for the relationships involved. More generally, the ability to define a coherent self involves this ability to separate one relationship from another.
--- As has been demonstrated in the research of Walter Toman, interpersonal style is significantly predicted by the birth order and sex of oneself and one's siblings and that of one's recent ancestors. Furthermore, the complementarity of marital, work, and other later relationships can be understood based on the birth order and sex in sibling constellations.
--- Differentiation of self develops and operates in a social context. Loss of effective contact with significant others, especially from the multi-generational family, is a sign of lower differentiation of self and serves to block efforts toward greater differentiation. Conversely, efforts toward differentiation are facilitated by thoughtful contact with the multi-generational family and other key relationships.
--- In addition to the variables already cited the current functioning level of society, or subsets of society, also affect individual and family functioning. Society tends to oscillate in its functioning level and tends to regress during major shifts in population density and when access to natural resources is diminished.
--- Finally, the theory remains open to unexplained or "supernatural" phenomena such as intuition, coincidence, and premonition, with the expectation that these too will eventually be understood as systems phenomena related to objective, real-world variables.