Operant conditioning represents a unique data language that describes the lawfulness of behavior as derived from the cumulative record over time of consistent correlations between the universally observed or 'public' form or topography of behavior and its consequences. Operant conditioning procedures are based upon methodological principles, wherein reliable behavioral consistencies or 'laws' are derived using a data language that precisely maps to the universally agreed upon facts of behavior. As a form of methodological behaviorism (Pavlovian or classical conditioning is another example), the experimental methodology of operant conditioning directly measures and manipulates only publicly observable behavior. Grasping, walking, talking, etc. are operant behaviors because they are correlated with or are 'reinforced' by specific discrete outcomes. Because these behaviors uniformly engage a specific organelle of the body, namely the striated musculature, a common presumption is that operant conditioning primarily reflects the conditioning of these muscles. Of course, convulsions, startle reactions, etc. do involve the striated musculature and can be mediated by neurological rather than purely cognitive causes, but in general muscular activity is guided by its functionality as consciously perceived.
It is commonly assumed that if striated muscles are activated, they are publically observed, and hence may be subsumed entire under an operant analysis. Yet only a fraction of striated muscular activity is observable publicly or privately. That is, the musculature may be activated yet not result in publicly observable responses, and neither may it be consciously or privately perceived by the individual. Ironically, the private activity of the musculature has long been made public through resolving instrumentalities (e.g., SCR, EMG) but rarely if ever has an operant analysis been employed to explain this behavior. Rather, tension has generally been construed to be an artifact of autonomic arousal that is elicited due to psycho-social 'demand'. This interpretation regards muscular tension as subsumed under different motivational principles that do not incorporate contingency, such as the reflexive or S-R responses entailed by a fight or flight response, stress reaction, etc. (Marmot & Wilkinson, 2006). In this case, inferred mediating processes take the place of observed correlations between behavior and environmental events.
However, this conclusion may remain uncontested not because the relationship between tension and its governing contingencies is disproven, or because the relevant data are unobtainable, but because of a common misinterpretation of the semantics of 'demand'. The purpose of this article is to argue that the same data and data language used to establish the concept that tension is reflexive or is a respondent can be reinterpreted to unequivocally demonstrate that muscular tension is an instrumental or operant behavior.
The Striated Musculature
Although the activity of the striated musculature comprises the majority of behavior as we understand it, its psychophysiology is not widely known. Muscle fibers are categorized into "slow-twitch fibers" and "fast-twitch fibers" (Squire, McConnell, & Zigmund, 2003). Slow-twitch fibers (also called "Type 1 muscle fibers") activate and deactivate slowly, but when activated they are also very slow to fatigue. Fast-twitch fibers activate and deactivate rapidly and come in two types: "Type 2A muscle fibers" which fatigue at an intermediate rate, and "Type 2B muscle fibers" which fatigue rapidly. These three muscle fiber types (Types 1, 2A, and 2B) are contained in all muscles in varying amounts. Muscles that need to be activated much of the time (like postural muscles) have a greater number of Type 1 (slow) fibers. When a muscle begins to contract, primarily Type 1 fibers are activated first, followed by Type 2A, then 2B. Type 1 fibers are often monotonically activated because of psychosocial 'demand' that in general does not engage fast twitch fibers. …