Limiting deception in groups of social agents

In open environments there is no central control over agent behaviors. On the contrary, agents in such systems can be assumed to be primarily driven by self-interests. Under the assumption that agents remain in the system for significant time periods, or that the agent composition changes only slowly, a prescriptive strategy has been previously presented for promoting and sustaining cooperation in the group. This strategy was shown to improve both individual and group performance in the long run. The prescribed strategy has been an adaptive, probabilistic, reciprocity-based policy for deciding which other individual to cooperate with. In this paper two mechanisms are investigated to limit exploitation of the reciprocative strategy by deceptive agents: 1) a penalty factor for declining requests for help, and 2) a cutoff limit on outstanding balance of help. The relative effectiveness of these mechanisms is evaluated for augmenting robustness of agent behaviors, without adversely affecting performance of ho...