by Paul Grossman, Gareth L. Ackland, Andrew M. Allen, Gary G. Berntson, Lindsea C. Booth, Gordon M. Burghardt, Julie Buron, Vladimir Dinets, J. Sean Doody, Mathias Dutschmann, David G.S. Farmer, James P. Fisher, Alexander V. Gourine, Michael J. Joyner, John M. Karemaker, Sahib S. Khalsa, Edward G. Lakatta, Cleo A.C. Leite, Vaughan G. Macefield, Benedito H. Machado, Robin M. McAllen, Clément Menuet, David Mendelowitz, Davi J.A. Moraes, Winfried Neuhuber, Matteo M. Ottaviani, David J. Paterson, Julian F. Paton, Peter R. Pellegrino, Rohit Ramchandra, Julia Shanks, James S. Schwaber, Kalyanam Shivkumar, K. Michael Spyer, Edwin W. Taylor, J. Andrew Taylor, Tobias Wang, Song T. Yao, Irving H. Zucker

Thirty-nine highly acknowledged experts in the areas of the physiology and the evolution of the vagus nerve and of vertebrate social behavior (many whose works have been cited in the polyvagal theory [PVT] literature as supporting the theory) were invited by the first author to participate as co-authors of this article. They were asked to evaluate the PVT and comment upon an overview of the theory written by its author (Porges, 2025a). All those invited, save one, accepted and co-authored the paper. The dissenting scholar was “unfamiliar with the PVT.” This article specifically appraises--based upon the current state of knowledge of autonomic function and vertebrate evolution--several major elements of the PVT, as described in Porges (2025a) and elsewhere. These include: 1) the validity of PVT assumptions that respiratory sinus arrhythmia is a direct measure of the extent of central vagal drive to the heart; 2) PVT characterizations regarding the neuroanatomy and functions of two major brainstem vagal nuclei, the ventrally situated Nucleus Ambiguus and the Dorsal Motor Nucleus of the vagus nerve; 3) PVT assertions regarding the evolution of the vagus nerve; 4) PVT claims about the specificity of mammalian social behavior in relation to nonmammalian vertebrates, and 5) PVT interpretations of earlier seminal physiological literature. All co-authors agree that major tenets of the PVT are not supported by past or current knowledge and, in several instances, are inconsistent with the broader evidence base. Since the topics addressed constitute fundamental premises of the PVT, we conclude that the PVT is untenable, because it is not defensible based on existing neurophysiological and evolutionary evidence. The psychological elements composing the superstructure of the PVT are primarily derived from earlier psychological literature and are neither clarified nor strengthened by PVT constructs that lack evidence. This article does not intend to address alternative explanations about relations between vagal function and psychological processes, although such explanations do exist.

Key words: polyvagal, vagus nerve, parasympathetic, autonomic nervous system, respiratory sinus arrhythmia, respiratory heart-rate variability