When Linear Behavioral Models Lose Explanatory Power Under Stress: A State-Dependent Conceptual Analysis

Behavior-analytic interpretations traditionally rely on linear relations among antecedents, behavior, and consequences under conditions of instructional control and relatively stable responses. However, in applied contexts, observable and measurable behavior may vary substantially under physiological stress even when external contingencies and task conditions remain nominally constant (McEwen, 1998; Sterling & Eyer, 1988). This paper presents a state-dependent conceptual analysis that examines why linear behavioral interpretations become insufficient under conditions of physiological load (Bouton, 1993). This study introduces a nonlinear, physiology-centered framework in which physiology is the primary organizing variable through which antecedents and consequences acquire functional significance. Within this framework, observable behavior is conceptualized as the downstream expression of physiological state within the antecedent–physiology–consequence loop, rather than as the primary causal driver. This model clarifies why instructional access, reinforcement sensitivity, and learning may vary across physiological states without requiring changes in external contingencies. The model has direct implications for behavior-analytic assessment, intervention sequencing, and ethical practice, emphasizing physiological regulation prior to instruction as a necessary precondition for effective teaching and sustainable behavioral change.