title: Criminal defectors lead to the emergence of cooperation in an experimental, adversarial game.
abstract: While the evolution of cooperation has been widely studied, little attention has been devoted to adversarial settings wherein one actor can directly harm another. Recent theoretical work addresses this issue, introducing an adversarial game in which the emergence of cooperation is heavily reliant on the presence of "Informants," actors who defect at first-order by harming others, but who cooperate at second-order by punishing other defectors. We experimentally study this adversarial environment in the laboratory with human subjects to test whether Informants are indeed critical for the emergence of cooperation. We find in these experiments that, even more so than predicted by theory, Informants are crucial for the emergence and sustenance of a high cooperation state. A key lesson is that successfully reaching and maintaining a low defection society may require the cultivation of criminals who will also aid in the punishment of others.
authors: Department of Mathematics, California State University, Northridge, Los Angeles, California, United States of America.
authors: Maria R
authors: MR
authors: D'Orsogna
authors: Ryan
authors: R
authors: Kendall
authors: Michael
authors: M
authors: McBride
authors: Martin B
authors: MB
authors: Short
mesh_terms: D003299:Cooperative Behavior; D057237:Criminals; D005716:Game Theory; D006801:Humans; D035846:Law Enforcement; D008962:Models, Theoretical
references: PLoS Comput Biol. 2010 Apr 29;6(4):e1000758
references: 20454464
references: Proc Natl Acad Sci U S A. 2003 Mar 18;100(6):3531-5
references: 12631700
references: Nature. 2002 Jan 10;415(6868):137-40
references: 11805825
references: Science. 2010 Apr 30;328(5978):613-7
references: 20431012
references: Proc Biol Sci. 2003 May 22;270(1519):1099-104
references: 12803901
references: Phys Rev E Stat Nonlin Soft Matter Phys. 2010 May;81(5 Pt 2):057104
references: 20866359
references: Science. 2010 Apr 30;328(5978):617-20
references: 20431013
references: Trends Ecol Evol. 2007 Nov;22(11):593-600
references: 17963994
references: Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Dec;82(6 Pt 2):066114
references: 21230712
references: Nature. 2003 Oct 23;425(6960):785-91
references: 14574401
references: Science. 2006 Jan 6;311(5757):47-52
references: 16400140
references: Science. 2007 Jun 29;316(5833):1905-7
references: 17600218
references: Nature. 2004 Nov 25;432(7016):499-502
references: 15565153
references: J Theor Biol. 2001 Jan 7;208(1):79-89
references: 11162054
references: Science. 1997 Aug 15;277(5328):918-24
references: 9252316