RT Journal Article T1 Reputation drives cooperative behaviour and network formation in human groups A1 Cuesta, José A. A1 Gracia-Lázaro, Carlos A1 Ferrer, Alfredo A1 Moreno, Yamir A1 Sánchez, Angel AB Cooperativeness is a defining feature of human nature. Theoreticians have suggested several mechanisms to explain this ubiquitous phenomenon, including reciprocity, reputation, and punishment, but the problem is still unsolved. Here we show, through experiments conducted with groups of people playing an iterated Prisoner's Dilemma on a dynamic network, that it is reputation what really fosters cooperation. While this mechanism has already been observed in unstructured populations, we find that it acts equally when interactions are given by a network that players can reconfigure dynamically. Furthermore, our observations reveal that memory also drives the network formation process, and cooperators assort more, with longer link lifetimes, the longer the past actions record. Our analysis demonstrates, for the first time, that reputation can be very well quantified as a weighted mean of the fractions of past cooperative acts and the last action performed. This finding has potential applications in collaborative systems and e-commerce. PB Nature Publishing Group SN 2045-2322 YR 2015 FD 2015-01-19 LK https://hdl.handle.net/10016/20182 UL https://hdl.handle.net/10016/20182 LA eng NO This work was supported in part by MINECO (Spain) through grants PRODIEVO, FIS2011-25167, and FIS2009-09689, by Comunidad de Madrid (Spain)through grant MODELICO-CM, by Comunidad de Aragón (Spain) through a grant to the group FENOL, and by the EU FET Proactive project MULTIPLEX (contract no. 317532). DS e-Archivo RD 27 jul. 2024