MASCOT: Multi-Agent Socio-Collaborative Companion Systems

Yiyang Wang, Yiqiao Jin, Alex Cabral, Josiah Hester


Abstract
Multi-agent systems (MAS) are emerging as promising socio-collaborative companions for emotional and cognitive support. However, existing systems frequently suffer from persona collapse, where agents revert to generic, homogenized assistant behaviors, and social sycophancy, where agents produce redundant, non-constructive dialogue. We propose MASCOT, a multi-agent framework for multi-perspective socio-collaborative companions. MASCOT introduces a novel bi-level optimization strategy to harmonize individual and collective behaviors: 1) Persona-Aware Behavioral Alignment, an RLAIF-driven pipeline that fine-tunes individual agents for agent-specific identities; and 2) Collaborative Dialogue Optimization, a group-level adaptation process that promotes complementary, diverse, and productive discourse. We evaluate MASCOT using human-grounded contexts drawn across both in-domain and out-of-domain (OOD) settings against state-of-the-art baselines. MASCOT improves persona consistency by up to +14.1 and social contribution by up to +10.6. A broad evaluation suite, including human evaluation, multiple LLM judges, three-way comparisons, and automatic metrics, further shows that MASCOT produces more role-consistent and less redundant multi-agent dialogue. Our code is available at https://github.com/hello-diana/MASCOT.
Anthology ID:
2026.emnlp-main.878
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
20293–20313
Language:
URL:
https://aclanthology.org/2026.emnlp-main.878/
DOI:
Bibkey:
Cite (ACL):
Yiyang Wang, Yiqiao Jin, Alex Cabral, and Josiah Hester. 2026. MASCOT: Multi-Agent Socio-Collaborative Companion Systems. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 20293–20313, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
MASCOT: Multi-Agent Socio-Collaborative Companion Systems (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.878.pdf