Simulating Reputation Dynamics and Their Manipulation - An Agent Based Model Framework

Abstract

Reputation is essential to human interactions and shapes group dynamics, however, it can be manipulated. The aim of this paper is to identify key aspects of reputation dynamics that eventually lead to a successful smearing campaign. For this purpose, we introduce an agent-based simulation which captures elements of communication dynamics that make agents more prone to believe lies, and to have an incorrect assessment of the honesty of others. The perceived honesty of agents being regarded here as their reputation, our simulations constitute a reputation game. Similarly to other works in the literature, the use of probability functions and Bayesian logic helps us to capture uncertainties in agents’ beliefs and to model their associated cognitive limitations. However a major novelty of our work with respect to previous simulations on trust and reputation networks is how bounded rationality is dealt with. In our game, agents use information theory to compress all the information available to them in order to capture their complex environment in memories with finite capacity. The imperfect reasoning which results from such a compression process makes our agents vulnerable to deception. We find that this eventually leads to the emergence of communication and behavioral patterns which resemble reality, such as for example echo chambers, self-deception, deception symbiosis, and freezing of group opinions. As a result, the framework we propose could be used to develop methods to mitigate the impact of harmful communication strategies, and in the future safeguard the communication dynamics influenced by artificial intelligence systems in social media.

Information and Agreement in the Reputation Game Simulation

“…In previous works [ 1 , 20 ] we used the optimal belief compression as described in Section 2.5.3 , as it follows information theoretical principles and ensures minimal information loss [ 21 ]. However, there are two reasons why we now question this choice.…”