The Behavior System Model of Nursing was developed by Dorothy E. Johnson. It stresses
the importance of research-based knowledge about the effect of nursing care on patients.
When she first proposed the theory in 1968, she explained that it was to foster "the
efficient and effective behavioral functioning in the patient to prevent illness."
Johnson explains four major concepts in her nursing model.
The human being has two major systems: the biological and behavioral systems. The role of medicine is to focus on the biological system, while nursing's focus is on the behavioral system.
Society relates to the environment in which the patient exists; a patient's behavior is directly influenced by the environment and events that occur in the environment.
Health is a purposeful adaptive response to internal and external stimuli in order to maintain stability and control. The responses include physical, mental, emotional, and social realms.
The primary goal of nursing is to foster equilibrium in the individual patient. One focus of nursing concerns the organized and integrated whole, but the major focus is on maintaining balance in the behavioral system during an illness in the biological system.
The assumptions made by the theory fall into three categories: assumptions about system, assumptions about structure, and assumptions about function.
There are four assumptions about system. They are:
There is "organization, interaction, interdependency, and integration of the parts and elements of behaviors that go to make up the system."
A system "tends to achieve a balance among the various forces operating within and upon it," and patients continuously strive to maintain balance in their behavioral systems by automatic adjustments and changes to the natural forces.
A behavioral system, which requires some measure of regularity and constancy in behavior, is essential to the patient in that it has an important purpose in social life, as well as for the individual.
"System balance reflects adjustments and adaptations that are successful in some way and to some degree."
There are also four assumptions about structure and function of each subsystem. First,
"from the form the behavior takes and the consequences it achieves can be inferred what
'drive' has been stimulated or what 'goal' is being sought." Each individual has a
"predisposition to act with reference to the goal, in certain ways rather than other ways,
"which is called a "set." Each subsystem has a range of choices called a "scope of action."
Finally, it produces an "observable outcome," which is the patient's behavior.
Johnson identifies seven subsystems in the Behavioral System Model. They are:
Attachment or affiliative subsystem, which is "social inclusion intimacy and the formation and attachment of a strong social bond."
Dependency subsystem, which is the "approval, attention or recognition and physical assistance."
Ingestive subsystem, in which "the emphasis is on the meaning and structures of the social events surrounding the occasion when the food is eaten."
Eliminative subsystem, which states that "human cultures have defined different socially acceptable behaviors for excretion of waste, but the existence of such a pattern remains different from culture to culture."
Sexual subsystem, which is both a biological and social factor that affects behavior.
Aggressive subsystem, which relates to the behaviors concerning protection and self-preservation, generating a defense response when there is a threat to life or territory.
Achievement subsystem, which provokes behavior that tries to control the environment.
Each subsystem also has three functional requirements. Each subsystem must be protected
from noxious influences that the system cannot cope with; each subsystem must be nurtured
with appropriate supplies from the environment; and each subsystem must be stimulated for
use in order to enhance growth and protect from stagnation. These behaviors are "orderly,
purposeful and predictable and sufficiently stable and recurrent to be amenable to
description and explanation."
Johnson defined nursing as "an external regulatory force which acts to preserve the
organization and integration of the patients behaviors at an optimum level under those
conditions in which the behaviors constitutes a threat to the physical or social health,
or in which illness is found."
She stated that nursing is "concerned with man as an integrated whole and this is the
specific knowledge of order we require." She also identified four goals of nursing,
which are to assist the patient:
whose behavior is in proportion with social demands.
who is able to modify his behavior in order to support biological imperatives.
who is able to benefit to the fullest extent during illness from the physician's knowledge and skill.
whose behavior does not give evidence of unnecessary trauma as a consequence of illness.
In terms of the nursing process, the Behavioral System Model is best applied in the
evaluation phase, during which time the nurse can determine whether or not there is
balance in the subsystems of the patient. If a nurse helps a patient maintain an equilibrium
of the behavioral system through an illness in the biological system, he or she has been
successful in the role.