Communication Enables Cooperation in LLM Agents: A Comparison with Curriculum-Based Approaches

Hachem Madmoun, Salem Lahlou


Abstract
Eliciting cooperation in multi-agent LLM systems is critical for AI alignment. We investigate two approaches: direct communication and curriculum learning. In a 4-player Stag Hunt, a one-word "cheap talk" channel increases cooperation from 0% to 48.3%, demonstrating communication as a robust coordination mechanism. In contrast, we find that curriculum learning is highly sensitive to design choices: our pedagogical curriculum through progressively complex games reduced agent payoffs by 27.4% in an Iterated Public Goods Game with Punishment. Qualitative analysis reveals that curricula emphasizing defection-equilibrium games can induce "learned pessimism" in agents. These findings suggest that for coordination problems, simple communication protocols may be more reliable than experience-based training, and that curriculum design for social dilemmas requires careful attention to the strategic lessons embedded in game sequences.
Anthology ID:
2026.eacl-short.23
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
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EACL
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Publisher:
Association for Computational Linguistics
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Pages:
307–321
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-short.23/
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Cite (ACL):
Hachem Madmoun and Salem Lahlou. 2026. Communication Enables Cooperation in LLM Agents: A Comparison with Curriculum-Based Approaches. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers), pages 307–321, Rabat, Morocco. Association for Computational Linguistics.
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Communication Enables Cooperation in LLM Agents: A Comparison with Curriculum-Based Approaches (Madmoun & Lahlou, EACL 2026)
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