Definition
A feedback loop is a mechanism where the output of a system is circled back as input. Feedback loops are the “engines” of change and stability in any complex system, making them dynamic and responsive rather than static.
Why It Matters
Feedback loops are the “invisible steering wheels” of the world. Failing to recognize a positive loop (like a debt spiral or viral panic) leads to catastrophic overshoot, while failing to install a negative loop (like a budget or a circuit breaker) leads to instability. Mastering this mental model is the difference between being a victim of systemic forces and being the architect who can harness or dampen them.
Core Concepts
- Positive (Reinforcing) Feedback: The output amplifies the input, leading to exponential growth or “vicious cycles” (e.g., compounding interest, a bank run, or viral growth).
- Negative (Balancing) Feedback: The output counteracts the input, pushing the system back toward a target state or “Equilibrium” (e.g., a thermostat, hunger, or market supply and demand).
- Delay: The time it takes for feedback to hit the system. Long delays make systems very hard to control and lead to “overshooting” and oscillations.