International Encyclopedia of Systems and Cybernetics

K. BOULDING proposed a "… hierarchy of complexity, roughly corresponding to the complexity of the "individuals" of the various empirical fields" (1956, p.14-15).

The levels are as follows:

1 – The level of the static structure, or frameworks, "whose accurate description… is the beginning of organized theoretical knowledge in almost any field "

2. – The level of clockworks, "… simple dynamic systems with predetermined, necessary motions… Such a system may reach a position of stationary equilibrium, or it may not – there are plenty of examples of explosive dynamic systems"

3. – The level of the control mechanism or cybernetic system in which "… the transmission and interpretation of information is an essential part of the system… The homeostasis model… is an example of a cybernetic mechanism"

4. – The level of the "open system" or self maintaining structure. "This is the level at which life begins to differentiate itself from not-life. However "Something like an open system exists, of course, even in physicochemical equilibrium systems", wherein "structures maintain themselves in the midst of a throughput of electrons, molecules, etc… "

5. – The genetic-societal level, which is typified by the plant. "The outstanding characteristics of these systems are first, a division of labor among cells to form a cell-society with differentiated and mutually dependent parts… and second, a sharp difference between the genotype and the phenotype, associated with the phenomenon of equifinal or "blueprint" growth". See grammar, program.

6. – The animal level, "characterized by increased mobility, teleological behavior and self-awareness". As we ascend the scale of animal life, behaviors become more diversified, complex and coherently integrated.

7. – The human level: "… the individual human considered as a system… In addition to all, or nearly all, of the characteristics of animal systems, man possesses self consciousness, which is something different from mere awareness". Self-reflexivity is "… bound up with the phenomenon of language and symbolism "

8. – The level of social organizations. "The unit of such systems is not perhaps the person

- the individual human as such – but the "role"

- that part of the person which is concerned with the organization or situation in question"

Like any other classification, BOULDING's one can be questioned. It is however to be noted that, after nearly 40 years, it has not been basically contradicted by any subsequent experimental or theoretical development.