Polyvagal Theory: Science or Science-Fiction?

Researcher: Sophie J.

Research Editor: Linette Borges Our body’s autonomic nervous system (ANS) is regulated by a complex network of multi-systemic signaling pathways that work behind the scenes to keep us safe, both at rest and in danger. It contains 2 distinct branches, the sympathetic ‘fight-or-flight’ system, and the parasympathetic ‘rest-and-digest' system. These systems work in tandem to keep our body in the balanced physiological state of homeostasis, but have you ever heard that it may play a role in your emotional responses? Well, if you haven’t, let me introduce you to the Polyvagal Theory. This theory suggests that our ANS plays a larger role in our emotional regulation and connectedness than we may think.

The Polyvagal Theory was first introduced in 1994 by American neuroscientist and psychologist Dr. Steven Porges. Dr. Porges posits that feelings of safety experienced by any given individual are influenced by their internal physiological states regulated by the ANS (Porges, 2022). Or in simpler terms, feeling safe is our relative subjective interpretation of internal bodily feelings, and that these ‘feelings’ are delivered to our brains via the vagus nerve complex. Interestingly, this means that our feeling of internal ‘safety’ does not necessarily match our external circumstances (Porges, 2022). So, where one individual may feel safe shopping at the mall, another may not; despite a distinct lack of threat present in both scenarios.

(Polyvagal Institute, 2025)

The major underlying tenants to this Theory include its Hierarchical Model of Self-Regulation, which includes 4 distinct levels of functioning in the ANS (Porges, 2022). Level I is considered the ‘lowest’ order of processing (think brainstem), whereas Level IV is considered to be the ‘highest’ order of processing (think frontal cortex). So, by ways of this theory, when an individual is unable to process an emotion through all 4 levels, they are unable to properly reach a calmed state in which connection can be made in social settings (Porges, 2022). According to Dr. Porges, when an individual is ‘stuck’ processing emotions using ‘lower’ order brain structures, perhaps they are in ‘fight-or-flight’, they are diverting resources away from the maintenance homeostatic functions due to the high metabolic cost of such a stress response (Porges, 2022). This diversion then inhibits the person from feeling the sense of safety required to engage in cooperative social activities in a vulnerable and effective manner, decreasing well-being, creativity, and productivity (Porges, 2022).

However, Dr. Porges’ theory has been widely criticized since its inception, mainly for its reliance on the vagus nerve as central modulator for emotional and physiological sensory processing. The Polyvagal Theory relies heavily on the notion that the vagal system is almost solely responsible for an individual’s ability to adapt to their environmental challenges, balance health and disease, and act as a central ‘highway’ for peripheral information (Manzotti et. al., 2024). It fails to account for the complex multi-systemic nature of the human body, specifically the ANS’s responses to stress; lacking consideration of immune, endocrine, and other integral bodily systems. As humans, we have evolved by way of integrating our ‘old’ systems with the ‘new’, rather than having newer structures placed hierarchically above the more ‘primitive’ ways of functioning (Manzotti et. al., 2024).

In spite of this, Dr. Porges’ theory has maintained its place in various therapeutic settings, ranging from treatment of trauma and attachment styles, provided its explanation of emotional reasoning is more easily translatable to the general population. Despite its faults, the Polyvagal Theory provides a gentle framework for understanding emotional and trauma responses to stress and interpersonal situations, but it must be considered as only part of a much bigger equation.

References

Manzotti, A., Panisi, C., Pivotto, M., Vinciguerra, F., Benedet, M., Brazzoli, F., Zanni, S., Comassi, A., Caputo, S., Cerritelli, F., & Chiera, M. (2024). An in-depth analysis of the polyvagal theory in light of current findings in neuroscience and clinical research. Developmental psychobiology, 66(2), e22450. https://doi.org/10.1002/dev.22450

Polyvagal Institute. (2025). What is polyvagal theory? https://www.polyvagalinstitute.org/whatispolyvagaltheory

Porges S. W. (2022). Polyvagal Theory: A Science of Safety. Frontiers in integrative neuroscience, 16, 871227. https://doi.org/10.3389/fnint.2022.871227