Emergence of group hierarchy

Indeed in most opinion dynamics models ([12, 13, 7, 4, 14, 11], for a recent review see: [9]), apart from a few exceptions [1, 3, 10], opinions about the agents themselves are not considered as deserving any specific attention. However, the opinions about agents determine the social network of positive or negative connections, hence in some respect the social structure. Moreover, it is generally recognised that this social structure has a strong influence on the agents' opinions. This suggests that opinions about agents do matter. Several opinion dynamics models include such a structure and in some cases it is evolving. This is for instance the case of some versions of the social impact model [16, 15]. Moreover, other researches propose models of social structure dynamics, for instance hierarchies resulting from fights between primates [2]. In both cases, the social structure is generated by processes that are different from opinion dynamics. In this paper, we assume that the agents of the model proposed in [5, 8] belong to different groups.