RESEARCH ARTICLE Social Value Induction and Cooperation in the Centipede Game Briony D. Pulford 1☯ *, Eva M. Krockow 1☯ , Andrew M. Colman 1☯ , Catherine L. Lawrence 1,2☯ 1 Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom, 2 School of Psychology, Bangor University, Bangor, Wales, United Kingdom ☯ These authors contributed equally to this work. * bdp5@le.ac.uk Abstract The Centipede game provides a dynamic model of cooperation and competition in repeated dyadic interactions. Two experiments investigated psychological factors driving cooperation in 20 rounds of a Centipede game with significant monetary incentives and anonymous and random re-pairing of players after every round. The main purpose of the research was to determine whether the pattern of strategic choices observed when no specific social value orientation is experimentally induced—the standard condition in all previous investigations of behavior in the Centipede and most other experimental games—is essentially individual- istic, the orthodox game-theoretic assumption being that players are individualistically moti- vated in the absence of any specific motivational induction. Participants in whom no specific state social value orientation was induced exhibited moderately non-cooperative play that differed significantly from the pattern found when an individualistic orientation was induced. In both experiments, the neutral treatment condition, in which no orientation was induced, elicited competitive behavior resembling behavior in the condition in which a competitive ori- entation was explicitly induced. Trait social value orientation, measured with a question- naire, influenced cooperation differently depending on the experimentally induced state social value orientation. Cooperative trait social value orientation was a significant predictor of cooperation and, to a lesser degree, experimentally induced competitive orientation was a significant predictor of non-cooperation. The experimental results imply that the standard assumption of individualistic motivation in experimental games may not be valid, and that the results of such investigations need to take into account the possibility that players are competitively motivated. Introduction Cooperation and competition are the most quintessentially social forms of human behavior; in fact, it is difficult to think of any significant class of social interactions that does not involve cooperation or competition in some form. The Centipede game is an ideal tool for studying the motivational bases of reciprocal cooperation, because it is a dynamic game that presents players PLOS ONE | DOI:10.1371/journal.pone.0152352 March 24, 2016 1 / 21 OPEN ACCESS Citation: Pulford BD, Krockow EM, Colman AM, Lawrence CL (2016) Social Value Induction and Cooperation in the Centipede Game. PLoS ONE 11 (3): e0152352. doi:10.1371/journal.pone.0152352 Editor: Kimmo Eriksson, Mälardalen University, SWEDEN Received: January 5, 2016 Accepted: March 11, 2016 Published: March 24, 2016 Copyright: © 2016 Pulford et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The research reported in this article was supported by the Leicester Judgment and Decision Making Endowment Fund http://www2.le.ac.uk/ departments/psychology/research/JDMSP/leicester- judgment-and-decision-making-endowment-fund (Grant RM43G0176) to BDP and AMC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.