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Feedback

Prime #
12
Origin domain
Systems Thinking & Cybernetics
Also from
Engineering & Design, Earth Sciences
Aliases
Feedback Loop, Feedback Loops, Positive Feedback, Positive Feedback Loops, Reinforcing Loop, Self Reinforcing Loop, User Feedback
Related primes
Equilibrium, Self-Organization, State and State Transition

Core Idea

Cyclic processes where outputs influence subsequent inputs.

How would you explain it like I'm…

Loop Back

Your body has a little built-in thermostat. If you get too hot, you sweat to cool down. If you get too cold, you shiver to warm up. Your temperature tells your body what to do next, and what your body does changes your temperature, and around and around it goes. That circle, where what's happening now changes what happens next, is feedback.

Output Becomes Next Input

Feedback is when a system listens to itself. The thermostat in your house checks the temperature, turns the heater on if it's cold, and then checks again. If the heat overshoots, it shuts off. The output (warm air) loops back and changes the input (the measured temperature), which changes the next decision. Some loops calm a system down (negative feedback, like the thermostat). Others speed things up out of control (positive feedback, like a microphone screeching near a speaker).

Closed Cause-Effect Loop

Feedback means a system's own output is wired back in as part of its next input, closing a loop between cause and effect. Instead of a one-way chain (A causes B causes C), you get A causes B which loops back to influence A. Negative feedback opposes change and stabilizes a system: a thermostat, your body holding a steady temperature, prices nudging supply and demand toward balance. Positive feedback reinforces change and can run away: a microphone howl, a viral rumor, a snowball rolling downhill. Three knobs matter for any loop: its sign (calming or amplifying), its strength (how much the output pushes back), and its delay (how long the trip around the loop takes).

 

Feedback is the structural arrangement in which a portion of a system's output is routed back to influence its next input, closing a loop so that the present state depends on the system's prior output, not just external drivers. Every feedback arrangement specifies four things: (1) the variable being measured at the output, (2) the return path that carries that signal back to the input, (3) the sign and strength of coupling (negative feedback opposes the deviation and stabilizes; positive feedback reinforces it and amplifies), and (4) the timescale on which the loop closes. The closure is what defines feedback; without a return path you only have open-loop feedforward. Whether a feedback system converges, oscillates, or diverges depends jointly on the loop's sign, its gain (responsiveness), and its delay. The pattern is ubiquitous: homeostasis in organisms, market clearing, social norm enforcement, autoscaling in software, all rest on it.

Broad Use

Key in control systems, ecology, economics, and learning processes.

Clarity

Models dynamic systems, e.g., thermostat regulation or market corrections.

Manages Complexity

Provides a self-regulating mechanism to adjust systems dynamically.

Abstract Reasoning

Encourages cyclical reasoning and understanding of adaptive processes.

Knowledge Transfer

Central in engineering (control systems), biology (homeostasis), and economics (supply-demand loops).

Example

A thermostat adjusts heating based on the difference between the current temperature and the target temperature.

Relationships to Other Primes

Foundational — no parent edges in the catalog.

Children (22) — more specific cases that build on this

  • Checks and Balances presupposes Feedback — Checks and Balances presupposes Feedback: each branch's checks become inputs to the others' subsequent decisions and behavior.
  • Circuit Breaker presupposes Feedback — Circuit breaker presupposes feedback because the monitor-trip-reset loop routes the protected flow's state back to control its own continuation.
  • Conditioning (Behavioral) presupposes Feedback — Behavioral conditioning presupposes feedback because learned associations are forged by routing the consequence of a response back to modulate the response itself.
  • Flow State presupposes Feedback — Flow state presupposes feedback because the merging of action and awareness requires immediate, continuous return of information about the activity's progress.
  • Instability presupposes Feedback — Instability presupposes feedback because perturbations grow only when an amplification loop routes output back into input.

Not to Be Confused With

  • Feedback is not System Archetypes because Feedback is the general mechanism where system output influences inputs, whereas System Archetypes are recurring pattern structures (like reinforcing loops) within complex systems.
  • Feedback is not Homeostasis because Feedback is any information flow from output back to input, whereas Homeostasis is a specific type of negative feedback that maintains variables within a stable operating range.
  • Feedback is not Reflexivity (Self-Reference) because Feedback is information returned from a system's output to its input that influences behavior, whereas Reflexivity is the capacity of an entity to take itself as an object of attention or modification.