On this website, I love to revisit the major neurobollocks flourishing in the psychotherapy and selfโhelp worlds. I call out ideas that misuse the language of neuroscience to bolster practices that lack solid evidence. Today, letโs talk about oneโarguably the biggestโlurking under the guise of science in our fields: the vagus nerve hacks and Polyvagal Theory (PVT).
This isnโt your standard โlizardโbrainโ mythโitโs more insidious. Many neuroscientists barely know PVT exists, which means thereโs surprisingly little mainstream scientific pushback. Letโs pause there: the more a concept spreads unopposed, the more critical our scrutiny must become.
I wonโt fully debunk Polyvagal Theory todayโthat day is coming. But itโs worth flagging that Iโve spoken directly with neuroscientists and autonomic regulation experts. They tell me PVT takes a nerve that is important, detaches it from empirical grounding, then dresses it up in narrative storytelling. Thatโs never a good look for any therapy claiming scientific credibility.
So, today: Iโll lean into what feels safer and more practicalโexamining a narrow, specific case of vagus nerve marketing and how the literature doesnโt support it.
โMassage to activate the vagus nerveโ: A case study
The vagus nerveโthe bodyโs 10th cranial nerveโis undeniably vital. It swings from the brainstem down to organs like the heart, lungs, and gut, playing a crucial role in parasympathetic regulation and supporting interoception (how we sense our internal state). And yesโvagus nerve stimulation via electrical implants or transcutaneous devices is a real, scientifically studied approach.
But, thereโs a proliferation of wellness claimsโโvagus nerve massageโ, โvagal toningโ, โactivate your inner peaceโโtossed around without evidence.
Take one example from a โhormone expert and thought leader in womenโs medicine.โ She writes:
โVagus nerve stimulation (or VNS) refers to any technique that stimulates the vagus nerve, including manual techniques such as massagesโฆโ
And she references three studies. On closer inspectionโall three only involve electrical stimulation (implants or electrodes). None involve massage. One even promotes implanted devices. Yet the author then claims massage-based VNS improves โvagal toneโ and builds stress resilienceโwithout any citations.
Thatโs textbook misโcitยญing: stringing together terms like โvagal tone,โ โstress resilience,โ and โvagus nerve stimulationโ to imply support where none exists.
Science check: Whatโs the evidence (and what isnโt)?
1. Measuring vagal tone is complicated.
Whatโs often called โvagal toneโ is not a direct measure of vagus nerve activityโbut rather inferred from heart rate variability (HRV), especially respiratory sinus arrhythmia (RSA). Thatโs an index, not the tone itself. The relationship between vagal nerve activity and HRV is nonโlinear and modulated by many factorsโmaking simplistic interpretations misleading.
2. Polyvagal Theoryโs anatomical claims fall short.
Critics including Neuhuber & Berthoud (2022) point out that the theory mischaracterizes neural structuresโlike wrongly linking the dorsal vagal complex to passive โfreezeโ or asserting a unique โventral vagal complexโ innervating facial muscles, which it doesnโt.
3. Evolutionary foundations crumble.
PVT claims that certain vagal circuits are uniquely mammalianโbut evidence from lungfish and other vertebrates shows similar myelinated pathways in nonโmammals, undermining the โmammal-onlyโ premise.
4. Experts question the theoryโs overall validity.
Paul Grossmanโs 2023 review argues that all five core premises of PVT are untenable, suggesting that the foundational hypotheses have been falsified.
So where does that leave us?
- Personal experience is valid, but once a therapy claims neuroscience backing, it must rest on robust evidence. Youโve walked that lineโknowing what helped you most often had nothing to do with neuroscience yet still changed your life.
- Not all science-adjacent therapy is invalidโbut we must discern narrative from evidence and hold our claims to real scrutiny.
References
Doody, J. S., Burghardt, G., & Dinets, V. (2023). The evolution of sociality and the Polyvagal Theory. arXiv preprint. https://arxiv.org/abs/2304.09238
Grossman, P. (2023). Fundamental challenges and likely refutations of the five basic premises of the polyvagal theory. Biological Psychology, 178, 108543. https://doi.org/10.1016/j.biopsycho.2023.108543
Monteiro, D. A., Taylor, E. W., da Silva, G. S. F., Leite, C. A. C., & Gargaglioni, L. H. (2018). Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish. Science Advances, 4(4), eaaq0800. https://doi.org/10.1126/sciadv.aaq0800
Neuhuber, W., & Berthoud, H.-R. (2022). Functional anatomy of the vagus system: How does the polyvagal theory comply? Biological Psychology, 169, 108294. https://doi.org/10.1016/j.biopsycho.2022.108294
Taylor, E. W., Wang, T., & Leite, C. A. C. (2022). An overview of the phylogeny of cardiorespiratory control in vertebrates with reflections on the โPolyvagal Theoryโ. Biological Psychology, 169, 108295. https://doi.org/10.1016/j.biopsycho.2022.108295
Wikipedia contributors. (2024). Vagal tone. In Wikipedia. https://en.wikipedia.org/wiki/Vagal_tone
Wikipedia contributors. (2025). Polyvagal theory. In Wikipedia. https://en.wikipedia.org/wiki/Polyvagal_theory
Wikipedia contributors. (2025). Non-invasive vagus nerve stimulation devices. In Wikipedia. https://en.wikipedia.org/wiki/Non-invasive_vagus_nerve_stimulation_devices