Effects of tag mediation and structural balance on the evolution of cooperation on signed networks.

Tag-based ethnocentrism is the basic mechanism for explaining social identity in human behaviors. Combining game theory with structural balance, the present study proposed a novel evolutionary game model in signed networks considering the tag-mediated effect, which provides a new perspective for explaining collective dynamics in social systems. Experiments show that negative relations promote the unconditional cooperation, and the conditional strategy is less likely to appear in the evolution in signed networks. Network adaption is helpful in reducing the proportion of unconditional defectors, but it can be mediated by the tag-based effect. The unconditional cooperation prevails when the speed of relation updating is faster than that of strategy updating increases to a certain extent. The evolution of structural balance can be capable of reducing the proportion of ethnocentric players. From a global point of view, the tag-mediated effect stimulates the formation of attractors or repeller structures, but the dynamic structural balance prevents the formation.