How and why to focus on causality in teaching human physiology

Two essentials to the process of developing critical thinking skills in human physiology students are, 1) explanation of the evolutionary adaptiveness of anatomical and physiological components - i.e., utilizing their “adaptive logic” to impart comprehension of their rational functioning and, 2) linking of physiological actions and responses within a process through conveyance of their causal relationships (1). Philosophers have for centuries argued that this latter element is essential to our predictive abilities within complex systems. The essential nature of causality is tied to the fact that all logically valid predictions rely on an understanding of the link between cause and effect determined by prior observations. Fundamentally, predictions are a form of inductive reasoning wherein expectations about unobserved things are based upon those which are observed. In the case of physiology, prior studies provide the evidence of physical, chemical or biological causes linking all steps within any mechanistic physiological sequence. We suggest that emphasis on causality and how it is packaged within our teaching is a critical foundation for all effective teaching, including the established educational initiatives intending to improve critical thinking skills in physiology (i.e., active learning, computer-based education, flipped classrooms, problem-based learning, and a focus on core concepts). In essence, complex physiological sequences should be initially explained as a series of simple triads (stimulus → causal link → effect). Doing so limits the load placed on working (short-term) memory, enhancing the storage of long-term memory and the formation of essential cognitive architecture required for critical thinking.