When subjected to a sudden, unanticipated threat, human groups characteristically self-organize to identify the threat, determine potential responses, and act to reduce its impact. Central to this process is the challenge of coordinating information sharing and response activity within a disrupted environment. In this paper, we consider coordination in the context of responses to the 2001 World Trade Center (WTC) disaster. Using records of communications among 17 organizational units, we examine the mechanisms driving communication dynamics, with an emphasis on the emergence of coordinating roles. We employ relational event models (REMs) to identify the mechanisms shaping communications in each unit, finding a consistent pattern of behavior across units with very different characteristics. Using a simulation-based “knock-out” study, we also probe the importance of different mechanisms for hub formation. Our results suggest that, while preferential attachment and pre-disaster role structure generally contribute to the emergence of hub structure, temporally local conversational norms play a much larger role in the WTC case. We discuss broader implications for the role of microdynamics in driving macroscopic outcomes, and for the emergence of coordination in other settings.

当受到突然的、意想不到的威胁时，人类群体通常会自我组织以识别威胁、确定潜在的反应并采取行动减少其影响。这个过程的核心是在中断环境中协调信息共享和响应活动的挑战。在本文中，我们在应对 2001 年世界贸易中心 (WTC) 灾难的背景下考虑协调。我们使用 17 个组织单位之间的通信记录，检查驱动通信动态的机制，重点是协调角色的出现。我们采用关系事件模型 (REM) 来识别塑造每个单元中通信的机制，从而在具有非常不同特征的单元之间找到一致的行为模式。使用基于模拟的“敲除”研究，我们还探讨了不同机制对枢纽形成的重要性。我们的结果表明，虽然偏好依恋和灾前角色结构通常有助于枢纽结构的出现，但暂时的本地会话规范在 WTC 案例中发挥了更大的作用。我们讨论了微观动力学在推动宏观结果中的作用以及其他环境中协调的出现的更广泛影响。