The Utility of Categories through their Recommendation in an Agents World with Local or not Local Communication

In this paper we focus on the importance of generalized knowledge: agents' categories. The cognitive advantage of generalized knowledge can be synthesized in this claim: "It allows us to know a lot about something/somebody we do not directly know". At a social level this means that I can know a lot of things on people that I never met; it is social "prejudice" with its good side and fundamental contribution to social exchange. In this study we experimentally inquire the role played by categories' reputation with respect to the reputation and opinion on single agents: when it is better to rely on the first ones and when are more reliable the second ones. We will consider two different scenarios: one strongly influenced by the spatial distance between agents (localized world); the other totally independent by the spatial distances (non-localized world), quite similar to the modern web society, in which the communicative distance follows different routs with respect to the spatial distance. We want to investigate how the parameters defining the specific environment (number of agents, their interactions, transfer of reputation, and so on) influence the importance of categories' reputation in these two different worlds.