Evaluator bias in LLM-based multi-agent systems spreads between agents like contagion, but using multiple evaluators (k=3 vs k=1) cuts this propagation by 72%—a simple mitigation for production systems.
This paper studies how evaluation biases spread through multi-agent LLM systems. Using a mathematical framework called Contagion Networks, researchers measured how one agent's evaluator bias influences other agents' behavior in a 3-agent system.