Coexisting Agents: Experiments on Basic Interaction Attitude

This paper deals with the problem of coexistence in the same environment of agents with different fixed attitudes toward each other. Agents that are endowed with distinct 'help-seeking' and 'help-giving' strategies have been defined and simulated in a multi-agent system, and the effect of their behavior on the global performance of the system has been measured. The experimental environment can be considered a good metaphor for a task that needs no social coordination and must be performed autonomously by each agent but, at the same time, can be affected by the other agent's cooperative attitude and produces global effects on the system. In three sets of experiments we investigated different aspects: Study 1 shows the utility of the 'social' attitude (characterizing agents that both give and ask for help) with respect to the selfsufficient one; Study 2 shows how social agents are able to tolerate the presence of exploiters; Study 3 shows how the robustness of the social strategy is tested by putting help-giving under various risky conditions. The results reveal the general robustness of the social attitude and its usefulness for the whole system. The results also point to the varying degrees of dangerousness and robustness of different exploitation strategies, according to the different environmental conditions in which the exploiters are placed. Corresponding author: tel: +39-06-86090-209, fax: +39-06-824737 e-mail: cesta@ip.rm.cnr.it 'e-mail: miceli, paolag@ip.rm.cnr.it