What is Polyvagal Theory, and what are its limitations?
- drissboussaoud
- Apr 8
- 7 min read
Why do some situations soothe us almost immediately, while others trigger stress, panic, tension, or withdrawal? Why can the presence of a reassuring person sometimes calm the body, while an environment perceived as threatening is enough to put us on high alert?
Polyvagal theory offers an influential answer to these questions by placing the vagus nerve at the heart of emotional regulation. Developed by Stephen Porges, it describes how our autonomic nervous system organizes itself according to different physiological states related to safety, defensive mobilization, or freezing. This approach has had a significant impact in the fields of trauma, psychotherapy, and psychoeducation because it provides an accessible language for connecting body, emotions, stress, and relationships .
Today, it inspires numerous practices: breathing exercises, meditation, grounding techniques, yoga, inner security work, and paying attention to bodily signals. Its success also stems from this: it has helped to put the body back at the center of understanding stress and trauma. But what does science actually say? Is polyvagal theory firmly established from a neurophysiological standpoint? And what are its limitations?
The vagus nerve: an important player in bodily regulation
As its name suggests, the polyvagal theory is organized around the vagus nerve , one of the major nerves of the autonomic nervous system. It connects the brainstem to many internal organs, including the heart, lungs, and digestive system.
The vagus nerve is a mixed nerve, composed primarily of afferent fibers : approximately 80% transmit information from the body to the brain, while about 20% are efferent fibers that transmit commands from the brain to the organs. This structure highlights a key point: emotional regulation also depends on how the brain constantly receives and interprets signals from the body.
The vagus nerve plays an important role in parasympathetic functions , that is, the processes of rest, recovery, and energy conservation. It contributes in particular to cardiac, digestive, and visceral regulation, and participates in bidirectional communication between the brain and the body. This is why it occupies a significant place in several contemporary models of stress, resilience, and emotional regulation.
The general principles of polyvagal theory
Polyvagal theory was developed to explain how the autonomic nervous system regulates not only physiological responses to stress, but also relational behaviors and emotional states.
His central idea is that our body doesn't simply alternate between activation and rest, but between several modes of organization linked to the perception of safety or threat. From this perspective, the body constantly adjusts its state according to the context, often automatically.
This theory has been very successful in the field of psychotrauma, as it provides an intuitive framework for understanding why some people remain in a state of near-constant alertness, while others slip into numbness, withdrawal, or dissociation. This also explains its widespread adoption in the world of therapy, psychoeducation, and personal development.
The three states described by polyvagal theory
1. The ventral vagal state: safety and social engagement
According to polyvagal theory, this state is associated with the ventral branch of the vagus nerve. It corresponds to a situation where the organism feels safe enough to be present, calm, and connected.
This state would favor:
relative relaxation,
relational commitment,
social communication,
emotional regulation,
greater physiological flexibility.
Clinically, it corresponds to those moments when one feels grounded, able to reflect, to feel without being overwhelmed, and to remain connected with oneself as well as with others.
2. The sympathetic state: mobilization, fight, or flight
When the system perceives a threat, sympathetic activation increases. The body then prepares to act quickly. This can manifest as an accelerated heart rate, increased muscle tension, heightened alertness, and a fight-or-flight response.
This state is useful when facing danger. But when it becomes chronic, it can fuel anxiety, irritability, hypervigilance, or a feeling of being constantly under pressure.
3. The dorsal vagal state: freezing, inhibition, withdrawal
In polyvagal theory, this state is associated with the dorsal branch of the vagus nerve. It occurs when the threat is perceived as extreme or inevitable, and neither flight nor fight seems possible.
It may be accompanied by:
freezing,
psychophysiological slowing
fatigue or collapse,
emotional disconnection
dissociation or feeling of emptiness.
This state is often mentioned in the clinical study of trauma, particularly when people describe a deep withdrawal, a feeling of numbness or absence from themselves.
Psychological trauma and nervous system dysregulation
Trauma is not simply a painful memory. It can permanently alter threat detection, alert, and regulatory systems. In practice, this means the nervous system can become less flexible and more easily trained to adopt defensive responses.
Two main clinical profiles are often observed.
Hyperactivation
The person remains alert, tense, and overstimulated. This can manifest as:
chronic anxiety,
hypervigilance,
irritability,
sleep disorders,
body tension
difficulty getting back down.
Withdrawal or inhibition
Conversely, some people shift towards a more inhibited state:
emotional numbness,
slow-down,
bodily disconnection
withdrawal,
impression of emptiness
difficulty in mobilizing.
These two modes can alternate in the same person. Clinically, this is an essential point: traumatic suffering does not always manifest itself through visible agitation; it can also take the form of silent withdrawal, self-effacement, or a disconnection from one's sensations.
Why is polyvagal theory so successful in psychotherapy?
The reason polyvagal theory has had such an impact is that it offers something valuable: it allows us to name the lived experience of many people. It helps us understand that certain reactions are not weaknesses, but automatic protective responses.
In clinical practice, it primarily serves as a psychoeducational model . It helps patients recognize their internal states, observe their physiological shifts, and gradually develop greater security and regulation.
It has inspired many approaches, including:
breathing,
anchoring exercises,
mindfulness,
gentle physical practices,
self-compassion,
the quality of the therapeutic setting,
support through secure relationships.
In this respect, her contribution is real: she has helped to make complex concepts about stress, trauma and emotional regulation more accessible.
The scientific limitations of the polyvagal theory
This is where an important nuance must be introduced. The fact that a theory is clinically useful does not automatically mean that it is scientifically validated in all its details .
However, for several years now, numerous researchers have highlighted the neurophysiological limitations of the polyvagal theory. These criticisms focus in particular on:
the assignment of very specific functions to the different branches of the vagus nerve,
certain evolving claims deemed simplistic,
the lack of solid empirical evidence for several central mechanisms of the model,
a sometimes selective reading of the available data.
In other words, many clinicians find this theory compelling and useful, but that is not enough to make it a definitively established neuroscientific theory.
It is therefore more accurate today to consider it as a heuristic and clinical model , interesting for thinking about emotional regulation, but whose foundations remain debated.
A useful metaphor, but not to be taken literally.
Polyvagal theory is often presented using a simple metaphor:
The ventral vagal would function as a flexible and adjustable brake, promoting calmness and connection;
the sympathetic nervous system would mobilize the energy necessary for action;
The dorsal vagal would act as an emergency brake, associated with blocking or collapse.
This image is useful in psychoeducation because it helps to understand how an organism can transition from calm to alert, and sometimes even to freezing. However, it should remain a clinical metaphor and not be confused with a complete neurophysiological description of what actually happens in the brain and body.
Beyond polyvagal theory: towards a more integrative vision of regulation
This is where the debate becomes particularly fruitful. Polyvagal theory has had the merit of bringing three essential dimensions back to the forefront:
the role of the body,
the importance of a feeling of safety,
the influence of the relationship on regulation.
But contemporary data suggest a broader framework. Emotional regulation probably doesn't depend on a single nerve, nor on a simplistic division into three states. It involves brain networks , attentional processes, contextual assessment, memory, traumatic history, bodily signals, and the presence of others .
In other words, what soothes or disorganizes us is not based solely on "vagal activation," but on a dynamic organization of the entire brain and body depending on the context. The quality of the relationship, the perception of safety, personal history, and attentional or mentalizing capacities all play a role.
It is from this perspective that the notion of presence becomes particularly interesting. Presence does not simply refer to a feeling of calm or security; it can be considered a condition that modifies our internal state, our attention, our emotional regulation, and our relational availability. From this point of view, the vagus nerve is undoubtedly just one element of a larger system.
Conclusion
Polyvagal theory has profoundly influenced how we talk today about stress, trauma, the body, and feelings of safety. It has had the merit of offering accessible, clinical, and often very clear language for both patients and therapists.
But from a scientific point of view, it must be approached with discernment. Several of its neurobiological hypotheses remain debated, and its formulations are sometimes more appealing than proven.
The most accurate position is probably to consider it a useful , but incomplete, clinical tool. It sheds light on certain dimensions of emotional regulation, but is not sufficient on its own to explain the complexity of human functioning.
Today, a more integrative approach seems necessary: an approach that holds together the body, the brain, trauma, attention, relationship, and presence.
To go further
You can continue this discussion with these blog articles:
Presence and the brain: why the mere presence of others alters our internal state
Emotional regulation: beyond the vagus nerve
EMDR, trauma and the brain: what really happens in therapy?
Why some relationships bring peace, while others bring chaos
If these questions resonate with you, it is often because they touch on something very concrete: chronic stress, anxiety, trauma, hypersensitivity, relationship difficulties, or a feeling of not being able to regain a state of inner security.
In psychotherapy, understanding these mechanisms already allows us to begin transforming them.
👉 To receive future articles on presence, neuropsychology and EMDR, subscribe to the newsletter.
References and further reading
Porges SW. Polyvagal Theory: A Science of Safety. Frontiers in Integrative Neuroscience, 2022.
Grossman P. Fundamental challenges and likely refutations of the five basic premises of the polyvagal theory. Biological Psychology, 2023.
Bonaz B, et al. Therapeutic Potential of Vagus Nerve Stimulation for Inflammatory Bowel Diseases. Frontiers in Neuroscience, 2021.
Breit S, et al. Vagus Nerve as Modulator of the Brain–Gut Axis in Psychiatric and Inflammatory Disorders. Frontiers in Psychiatry, 2018.
Goggins E, et al. Clinical perspectives on vagus nerve stimulation. Brain Stimulation, 2022.
🧠 Test your understanding:
Selon la théorie polyvagale, le mode vagal ventral est associé principalement à :
A. La réaction de combat ou fuite
B. Le figement et la dissociation
C. La sécurité, la connexion sociale et la régulation émotio
D. L’activation maximale du système sympathique
Dans votre expérience personnelle, vous reconnaissez-vous davantage dans une tendance à
l’hyperactivation (combat/fuite) ou
au repli (figement) face
Comments