Polyvagal Theory and Vagus Nerve Practices Cheat Sheet

Polyvagal Theory (PVT), developed by Stephen Porges in 1994, is a neurophysiological framework explaining how the autonomic nervous system (ANS) continuously organizes physiological state in response to cues of safety and threat. It argues that the ANS is not simply a two-branch system (sympathetic vs. parasympathetic) but a hierarchically organized network of circuits shaped by evolution, with the vagus nerve at its center. The core insight — that feeling safe is a biological prerequisite for connection, learning, and healing — has reshaped trauma therapy, somatic practice, and relationship science. Critically, PVT distinguishes between foundational neurophysiology and the applied metaphors and clinical language built on top of it; practitioners should hold this distinction clearly to avoid the oversimplification and pseudoscience risks that have drawn significant scientific criticism.