Feedback Loop
A circular process where a system’s output returns to influence its input, creating self-referential causality. The mechanism by which systems regulate themselves and produce complex behavior.
Formal Definitions
Mobus & Kalton (2015):
“Systems constantly adjust themselves by feedback loops, but when interdependent components operate with feedback loops of different temporal scales the system may become unstable. Systems science explicitly calls for attention to dynamics at all time scales in which conflicts could threaten the sustainability of the system.”
(Principles of Systems Science, Section 2.3, Principle 4: Dynamics)
Feedback loops are compositionally defined as: Sensing → Modulating → Propelling = Cybernetic control
(Process definitions in systems ontology)
Bunge (1979): Bunge does not provide an explicit definition of feedback loop in his systems ontology. In his framework, feedback would be formalized through cyclic relations in the structure set S, where output states at time t influence input states at time t+1.
(Implicit in A World of Systems, Chapter 1)
Types
Negative Feedback (Balancing)
- Output counteracts input deviation
- Produces stability, homeostasis, goal-seeking behavior
- Examples: thermostat, population regulation, blood sugar control
Positive Feedback (Reinforcing)
- Output amplifies input deviation
- Produces growth, collapse, or runaway change
- Examples: compound interest, viral spread, arms races
Synthesis
Mobus emphasizes the temporal scale problem: feedback loops operating at different speeds can destabilize systems. This connects to Principle 8: “Systems have governance subsystems to achieve stability.” Feedback is what transforms a collection of parts into an integrated whole capable of self-regulation.
Explore Further
- Behavior requires complete circuits — Bateson’s foundational insight on feedback as unit of analysis
- Cybernetic explanation is negative — Feedback operates through constraints
- Linear models miss feedback — Zwick’s critique of inadequate thinking
- Information as restraint — Bateson on information flow in feedback systems