Threshold Collapse Under Bounded Integrative Capacity: Cross-Domain Empirical Evidence

Abstract Complex systems that must sustain coordinated behavior under load often exhibit sudden breakdown following extended periods of apparent stability. These transitions are typically interpreted as responses to external disruption or shock. However, many systems fail without identifiable external discontinuity and under conditions in which activity persists or increases. Existing explanations based on shock, coordination failure, or general overload do not fully account for this pattern. This paper examines whether a common structural condition underlies such breakdown across domains. Using a structured coding framework, we analyze a set of empirically grounded cases spanning engineered networks, organizational systems, and biological and physical systems. The analysis identifies a recurring pattern: as accumulated load exceeds localized integrative capacity, systems undergo a nonlinear transition in which coordination degrades while signal persists or amplifies, without requiring external shock. The findings identify a distinct failure regime in which systems collapse under conditions of continued or increasing activity, rather than its absence. The structural condition that accounts for this pattern, bounded integrative capacity, is specified theoretically in Morgan (2026b). The present paper provides the cross-domain empirical support: systems remain coherent while distributed signal is integrated into coordinated action, but cross a threshold when the rate of signal exceeds the capacity of integrative structures, producing collapse under conditions of continued operation. The contribution lies in the demonstration that this pattern recurs across systems that differ in structure, scale, and substrate. The findings provide empirical grounding for a general account of threshold collapse that differs from models based on exogenous disruption. Keywords: threshold collapse; bounded integrative capacity; endogenous failure; signal accumulation; metabolization; cross-domain evidence; nonlinear transition; coordination failure; integrative structures; complex systems