arXiv:2508.08115v1 Announce Type: new Abstract: We present TeamMedAgents, a novel multi-agent approach that systematically integrates evidence-based teamwork components from human-human collaboration into medical decision-making with large language models (LLMs). Our approach validates an organizational psychology teamwork model from human collaboration to computational multi-agent medical systems by operationalizing six core teamwork components derived from Salas et al.'s "Big Five" model: team leadership, mutual performance monitoring, team orientation, shared mental models, closed-loop communication, and mutual trust. We implement and evaluate these components as modular, configurable mechanisms within an adaptive collaboration architecture while assessing the effect of the number of agents involved based on the task's requirements and domain. Systematic evaluation of computational implementations of teamwork behaviors across eight medical benchmarks (MedQA, MedMCQA, MMLU-Pro Medical, PubMedQA, DDXPlus, MedBullets, Path-VQA, and PMC-VQA) demonstrates consistent improvements across 7 out of 8 evaluated datasets. Controlled ablation studies conducted on 50 questions per configuration across 3 independent runs provide mechanistic insights into individual component contributions, revealing optimal teamwork configurations that vary by reasoning task complexity and domain-specific requirements. Our ablation analyses reveal dataset-specific optimal teamwork configurations, indicating that different medical reasoning modalities benefit from distinct collaborative patterns. TeamMedAgents represents an advancement in collaborative AI by providing a systematic translation of established teamwork theories from human collaboration into agentic collaboration, establishing a foundation for evidence-based multi-agent system design in critical decision-making domains.