Positive Feedback
Positive feedback amplifies winners and creates explosive growth - but is inherently unstable.
Positive feedback is powerful, but it needs negative feedback to stabilize. Amplification without brakes leads to instability.
On December 7, 1941, the USS Arizona exploded at Pearl Harbor. The forward magazine ignited, triggering a detonation so massive it lifted the 608-foot battleship out of the water. In 9 seconds, 1,177 sailors died.
Explosions are positive feedback. Heat triggers more combustion. More combustion generates more heat. The cycle accelerates until something runs out - fuel, oxygen, containment.
Biology uses positive feedback rarely, but when it does, it's for moments that need to be explosive.
Childbirth: The baby's head presses against the cervix. Stretch receptors detect this and signal the brain. The pituitary gland releases oxytocin. Oxytocin makes the uterus contract harder. Harder contractions push the baby further into the cervix, stretching it more. More stretch → more oxytocin → stronger contractions. The cycle escalates until the baby is born, at which point the stretch stops and the loop terminates.
Blood clotting: When a blood vessel tears, platelets stick to the injury site and release chemicals that attract more platelets. Those platelets release more chemicals. The aggregation accelerates, forming a clot in seconds. If this were a slow, measured response, you'd bleed out from a paper cut. Instead, positive feedback creates a rapid, localized plug.
The pattern is universal: positive feedback drives systems away from equilibrium, toward a new state. It's inherently unstable - which is exactly why it works for processes that need to happen now and then stop.
Business Application of Positive Feedback
Positive feedback amplifies winners and creates explosive growth - but is inherently unstable. Twitter's viral mechanics (likes → dopamine → more tweets → more followers → more likes) exemplify positive feedback driving growth. Airbnb's professional photography created positive feedback: better photos → more bookings → happier hosts → more hosts → more inventory. The danger: positive feedback without negative feedback leads to instability, as Twitter's toxicity problem demonstrated.