The persistent explanatory gap between local interactions and global emergence represents a fundamental challenge in complex systems science. While current frameworks successfully describe what components interact and their topological patterns, they lack a physical theory for how interactions are materially mediated and integrated—the crucial mechanism underlying self-organization. We propose the Interstitial Integration Hypothesis (IIH) as a comprehensive mechanistic framework. The IIH identifies the structure, dynamics, and material properties of interstitial spaces—the functional substrates between discrete components—as the physical determinant of system-level function and emergent behavior. Through convergent evidence from quantum physics to social science, we demonstrate that interstitial architecture governs how simple components give rise to complex phenomena through constrained flow and information processing. Crucially, we formulate specific, falsifiable predictions with detailed experimental protocols. This framework not only resolves longstanding puzzles of emergence but also reframes pathologies from fibrosis to social sclerosis as “intersticiopathies”—dysfunctions of interstitial flow—offering a transformative paradigm for engineering resilient systems across disciplines.
Wang et al. (Mon,) studied this question.