Does Human Group Psychology Transfer to Agent Collectives?

A team's emotional state bears on its output: one member's mood travels to the others, and the resulting composition predicts what the team produces. Collectives of language model agents now occupy much the same arrangement, and practitioners already configure their affect by assigning roles or by instructing agents to be skeptical. Whether the human regularities govern such collectives is nonetheless unestablished, since an instruction to feel anxious admits no graded intensity, while expressed text discloses only what an agent chooses to express. We therefore set each agent's state by intervening on its internal representations at calibrated intensities, and read every member's state from its activations on each round of deliberation. Affect does propagate, in proportion to the intensity applied, although the resulting shift is absent from the text the recipients produce and consequently invisible to a judge that reads it. What propagates, however, is frequently not what was injected: the targeted emotion leads the recipients' affective profile only within a bounded range of intervention strengths, and that range narrows as models grow. No configuration we examined improved group accuracy on any benchmark, whereas every emotionally configured group proved markedly more willing to adopt a confidently asserted wrong answer that unsteered groups disregard entirely. Affect in these collectives is accordingly a liability to be monitored rather than a lever to be pulled.