Green Bots versus Red Bots: Evaluating Large Language Models for Simulating Persuasion Dynamics in Online Influence Campaigns
Proceedings of the Fifteenth Language Resources and Evaluation Conference (LREC 2026)
Abstract
Large language models (LLMs) are increasingly used to simulate social interaction and persuasion dynamics, yet their validity as proxies for human cognition and behavior remains unverified. We propose a dual-level evaluation framework to assess LLM-based agents at both the individual and collective levels. At the individual level, we examine agent fidelity by comparing LLM-generated political personas to human benchmark data. We find that while agents capture broad partisan orientations, they underestimate within-group variability and reproduce stereotypical ideological biases. At the collective level, we deploy Big Five personality-differentiated agents in 1080 structured dialogues to test the effect of rhetorical strategy on persuasive success. Our simulations reproduce theoretically expected interaction patterns; nevertheless, belief shifts are exaggerated relative to human baselines, supporting LLMs’ tendency toward over-responsiveness. These findings suggest a trade-off between engagement-optimized training objectives and psychological realism, confirming the need to use LLMs with caution to simulate human behavior. We contribute three resources: a persuasion dynamics dataset, a standardized agent taxonomy of "red" and "green" bots, and a framework for evaluating both individual-agent fidelity and emergent group-level behavior.