Zero-sum bias

Biological Parallel

Humans intuitively treat social interactions as zero-sum: your gain is my loss. But biology is fundamentally positive-sum through mutualism. Mycorrhizal fungi exchange soil nutrients for plant sugars—both parties gain 40% more resources, total biomass increases, no loser exists. Cleaner wrasse remove parasites from reef fish—client fish survive 30% longer, cleaners get 100% of nutrition, both fitness values rise simultaneously. Flowering plants and pollinators co-evolved increased reproductive success simultaneously—not trade-offs. Yet humans negotiate salaries as zero-sum (higher wage = lower profit), structure trade as competitive (imports 'steal' jobs), frame immigration as resource competition. This bias exists because ancestral resource competition WAS zero-sum: finite meat from kills, fixed territory, limited mates. Modern economies create value through exchange, but Paleolithic brains still see fixed pies.