Agent swarms flip from belief collapse to belief polarization as population grows.

arXiv 2609.19124 builds a deliberately small testbed: a hidden country flag is ground truth, each agent sees only a private crop, agents exchange beliefs and weigh peer evidence. Even at that scale it reproduces non-monotonic scaling with population size, gains from social-awareness prompting and team diversity, and strong organizational-structure effects. Small populations collapse onto one belief; larger ones polarize, and that polarization drives the large-population performance decline while creating belief diversity. arXiv They introduce social circuit attribution to predict which agent and which view drives the outcome, verified by causal patching.