PNAS – Proceedings of the National Academy of Sciences of the United States
of America
http://www.pnas.org/content/early/
(Accessed 22 March 2014)

The reputational and social network benefits of prosociality in an Andean community
Henry F. Lyle IIIa,1 and Eric A. Smitha,b
Author Affiliations
Edited by H. Russell Bernard, University of Florida, Gainesville, FL, and approved February 6, 2014 (received for review October 2, 2013)
http://www.pnas.org/content/early/2014/03/12/1318372111.abstract

Significance
Scientists have long debated how group cooperation can be maintained. From many standard evolutionary and economic perspectives, the best decision for an individual is to engage in free riding on the cooperation of others (i.e., share in the benefits but pay no costs). Such free riding, however, reduces the collective benefits of group cooperation and can unravel cooperation. Some propose that this “tragedy of the commons” can be solved if cooperators are compensated with reputational benefits. Our research in an Andean community found that cooperative households have better reputations for various qualities and have larger support networks, with the latter associated with healthier households. This finding supports the argument that positive reputations gained by cooperators can solve the tragedy of the commons.

Abstract
Several theories have emerged to explain how group cooperation (collective action) can arise and be maintained in the face of incentives to engage in free riding. Explanations focusing on reputational benefits and partner choice have particular promise for cases in which punishment is absent or insufficient to deter free riding. In indigenous communities of highland Peru, collective action is pervasive and provides critical benefits. Participation in collective action is unequal across households, but all households share its benefits. Importantly, investment in collective action involves considerable time, energy, and risk. Differential participation in collective action can convey information about qualities of fellow community members that are not easily observable otherwise, such as cooperative intent, knowledge, work ethic, skill, and/or physical vitality. Conveying such information may enhance access to adaptive support networks. Interview and observational data collected in a Peruvian highland community indicate that persons who contributed more to collective action had greater reputations as reliable, hard workers with regard to collective action and also were considered the most respected, influential, and generous people in the community. Additionally, household heads with greater reputations had more social support partners (measured as network in degree centrality), and households with larger support networks experienced fewer illness symptoms.