Identifying Cooperative Personalities in Multi-agent Contexts through Personality Steering with Representation Engineering

As Large Language Models (LLMs) gain autonomous capabilities, their coordination in multi-agent settings becomes increasingly important. However, they often struggle with cooperation, leading to suboptimal outcomes. Inspired by Axelrod's Iterated Prisoner's Dilemma (IPD) tournaments, we explore how personality traits influence LLM cooperation. Using representation engineering, we steer Big Five traits (e.g., Agreeableness, Conscientiousness) in LLMs and analyze their impact on IPD decision-making. Our results show that higher Agreeableness and Conscientiousness improve cooperation but increase susceptibility to exploitation, highlighting both the potential and limitations of personality-based steering for aligning AI agents.

@article{ong2025_2503.12722,
  title={ Identifying Cooperative Personalities in Multi-agent Contexts through Personality Steering with Representation Engineering },
  author={ Kenneth J. K. Ong and Lye Jia Jun and Hieu Minh "Jord" Nguyen and Seong Hah Cho and Natalia Pérez-Campanero Antolín },
  journal={arXiv preprint arXiv:2503.12722},
  year={ 2025 }
}