{"slug":"paper-axelrod-r-and-hamilton-w-d-1981-the-evolution-of-cooperation-science-211-4489-13","verification":{"valid":true,"entries":1,"head":"474ace718b6722c77fc4b10a333031fda58894edd745a7e3c5b4b5dd4dd4f580"},"count":1,"sources":[{"id":"s1","type":"other","url":"https://www-personal.umich.edu/~axe/research/Axelrod%20and%20Hamilton%20EC%201981.pdf","title":"The Evolution of Cooperation","quote":"Cooperation in organisms, whether bacteria or primates, has been a difficulty for evolutionary theory since Darwin.","summary":"1981 Science paper by Axelrod and Hamilton modeling reciprocity in iterated games.","claim_ids":["c1","c2","c3","c4"],"found_by":"grok/grok-4.3","extra":{},"accessed_at":"2026-07-10T00:34:46.962Z","link_status":"timeout","quote_status":"unverified","prev":"genesis","hash":"474ace718b6722c77fc4b10a333031fda58894edd745a7e3c5b4b5dd4dd4f580"}]}