{"slug":"paper-axelrod-r-1984-the-evolution-of-cooperation-basic-books","verification":{"valid":true,"entries":1,"head":"e32eb4190a65f20578549c742f75d922d1d525c7e6caa3d8793e76942b766dcf"},"count":1,"sources":[{"id":"s1","type":"other","url":"https://ee.stanford.edu/~hellman/Breakthrough/book/pdfs/axelrod.pdf","title":"The Evolution of Cooperation by Robert Axelrod","quote":"This was a strategy of simple reciprocity which cooperates on the first move and then does whatever the other player did on the previous move. Using an American colloquial phrase, this strategy was named Tit for Tat.","summary":"Primary source PDF containing tournament descriptions and results.","claim_ids":["c1","c2","c3","c4","c5"],"found_by":"grok/grok-4.3","extra":{},"accessed_at":"2026-07-10T00:34:49.988Z","link_status":"ok","quote_status":"unverified","prev":"genesis","hash":"e32eb4190a65f20578549c742f75d922d1d525c7e6caa3d8793e76942b766dcf"}]}