The Identity-Fused Existential Threat Generalization Theory (IFETG): A Proposed Multilevel Framework for Non-Hostile Alternative-Induced Identity Threat, Defensive Regulation, and Feedback Dynamics

The Identity-Fused Existential Threat Generalization Theory (IFETG) is a proposed multilevel theoretical framework for understanding why an individual may experience a belief, ideology, worldview, or normative system as threatened by the presence or potential expansion of an alternative system even when the alternative presents no explicit hostile statement, direct attack, or declared intention to eliminate the original belief. The central proposition is that the psychological meaning of an alternative depends not only on its objective properties or its logical distance from the original belief, but also on how strongly the original belief is integrated into the individual's identity and whether the alternative is perceived as capable of displacing the belief's identity, social, moral, or institutional position.The framework distinguishes identity fusion from identity centrality, perceived substitutability from ideological difference, explicit threat evidence from perceived hostility, subjective threat from an independently calibrated threat benchmark, and defensive preference from enacted behavior. Its proposed default mechanism, Identity-to-Existence Threat Transfer (IETT), is complemented by Substitution-Sensitive Threat Generalization (SSTG) and the Identity Threat-Defense Feedback Loop (ITDFL). These mechanisms are organized across 19 theoretical layers spanning conceptual foundations, evolutionary and developmental background, cognitive and affective processing, epistemology, phenomenology, social identity, information environments, cybernetics, systems theory, mathematical formalization, measurement, causal identification, and falsifiability.The manuscript provides operational definitions, candidate equations, a time-dependent state-space formulation, ten testable hypotheses, illustrative case specifications, competing explanations, boundary conditions, a research roadmap, and a reproducible toy simulation. The mathematical expressions are candidate models rather than established laws. The manuscript reports no empirical dataset and does not claim that the proposed framework is a validated, universal, neurological, or clinical law. Its scientific value will depend on construct validity, identifiable causal mechanisms, comparative predictive performance, independent replication, and evidence that it explains outcomes beyond existing theories of identity, intergroup threat, moral conviction, uncertainty, and motivated reasoning.