The Parochial Default: An Integrative Framework of Affective Polarization as Entropy Minimization in Digitally Mediated Environments

Affective polarization in digitally mediated environments is commonly attributed to individual pathology, deliberate manipulation, or algorithmic information segregation ("echo chambers"). We propose an integrative framework in which polarization is instead the normal output of an evolutionarily ancient, metabolically inexpensive mode of social cognition — the parochial default, in which uncertainty reduction is achieved by closing moral space around an in-group/out-group boundary. Drawing on the free-energy principle, dual-process theory, moral foundations theory, cultural attraction theory, and secondary orality — operationalized as a vector of structural environmental parameters (reaction latency, re-emission cost, visibility of social approval, algorithmic amplification) — we argue that digital environments impose sustained informational entropy that the cognitive system resolves through capture by culturally attractive representations: threat narratives, binary schemata, and dominance hierarchies. Capture is experienced not as impairment but as gain: cognitive ease, epistemic closure, socially rewarded moral outrage, and identity fusion jointly render the captured state self-stabilizing and resistant to correction. Re-emission of attractor-consistent content enjoys a structural diffusion advantage, closing a self-reinforcing population-level loop that exhibits goal-like dynamics without central coordination. The framework accounts for otherwise anomalous findings, including null effects of algorithmic de-personalization and backfire effects of raw cross-cutting exposure, and yields six falsifiable propositions. Its central implication is a change of target: durable depolarization requires institutional and interface-level scaffolding that encodes reciprocal trust protocols and makes non-capture routes of uncertainty reduction structurally cheaper, rather than appeals to individual reflective effort, whose unreciprocated costs are unsustainable by design.