Plan continuation bias

Biological Parallel

Migrating birds continue toward traditional breeding grounds even when early arrivals report food failure—plan continuation bias overrides new information. Arctic terns migrate 44,000 miles annually; once committed to the plan (physiological preparation, 25-50% body mass as fat deposits, hormonal changes), updating based on distant signals is metabolically prohibitive. Wildebeest in Serengeti complete their 1,200-mile circuit even when drought conditions are reported ahead—rerouting costs more than continuing. The mechanism: plans create commitment through sunk physiological costs. Changing destination mid-migration requires navigational recalculation, new fat reserves, different route knowledge. Unless local conditions are catastrophic, continuing the plan is cheaper than revision. Businesses exhibit identical inertia: 73% of startups continue with failing strategies past pivot-optimal point due to sunk costs. Inertia is metabolically rational.