We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleVariation in behaviour promotes cooperation in the Prisoner's Dilemma game.AuthorsMcNamara JM; Barta Z; Houston AIPublicationNature, 2004, Vol 428, Issue 6984, p745ISSN1476-4687Publication typearticleDOI10.1038/nature02432