Behavior as a State-Dependent Physiological Outcome: A Nonlinear Integrative Framework

Behavior has traditionally been conceptualized within linear antecedent–behavior–consequence frameworks; however, such models inadequately account for the variability, inconsistency, and state-dependence observed across individuals and contexts. This article introduces a nonlinear physiology–behavior framework in which behavior emerges as the downstream expression of dynamic physiological state rather than as a direct product of environmental contingencies alone. The proposed Non-Linear Physiology–Behavior Equation (A ↔ P ↔ C ↓ B) conceptualizes physiology as a multisystem architecture comprising thirteen interacting physiological systems integrated across seven hierarchical layers, through which sensory, autonomic, interoceptive, hormonal, metabolic, and regulatory processes collectively determine behavioral availability. Within this model, antecedents and consequences acquire functional meaning only through their bidirectional interaction with physiological state, providing a mechanistic account of state-dependent learning, behavioral variability, and adaptive or maladaptive behavioral patterns. The framework generates testable predictions for research and offers a unifying foundation for assessment, interpretation, and intervention in behavioral science, with particular relevance to applied behavior analysis, clinical psychology, and developmental mental health contexts. This manuscript is currently under review at Frontiers in Psychology.