Polyvagal Theory According to Stephen Porges
Have you ever wondered why your body suddenly goes into alarm mode in stressful situations—or why you sometimes just “freeze” in certain moments? Our nervous system often reacts to external stimuli faster than we realize. The Polyvagal Theory developed by U.S. researcher Stephen Porges offers a fascinating explanation for this: It shows how deeply our emotional experiences, our bodies, and our need for safety are interconnected.
Whether in trauma therapy, stress management, or everyday life—the insights from this theory open up new ways to better understand your own nervous system and calm it in a targeted manner. But what exactly is behind it, and how can this knowledge be applied in practice? We’ve summarized all of this for you here in this article.
What is the Polyvagal Theory?
The Polyvagal Theory was developedby the American neurophysiologist Stephen W. Porges to explain how our autonomic nervous system responds to safety, danger, and threat. It is the first theory to integrate neurobiology, emotion, and social interaction—and is now considered a key to understanding stress, trauma, and human connection.
The Basic Idea
Our nervous system is constantly active—even when we think we’re relaxed. According to Porges, it continuously monitors our internal and external environments to assess whether we feel safe, in danger, or threatened. He calls this unconscious assessment process “neuroception.” This assessment occurs automatically and without conscious thought. It determines which physical and emotional state is activated. In this way, the nervous system forms the basis of our emotions, reactions, and social skills.
Key Features of This Theory
It describes safety as a biological signal—not a purely psychological one. Emotional reactions such as trust, fear, or withdrawal arise from physiological states, not just from thoughts. This brings bodily awareness to the forefront: it shows how closely the body and mind work together. A central component of this theory is the vagus nerve —a key communication pathway between the brain, heart, and organs. It plays a crucial role in how we process stress and experience a sense of safety.
In the next section, you’ll learn how this nerve works and why it’s so important for our well-being.
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The Role of the Vagus Nerve
The vagus nerve is one of the longest and most important nerves in the human body. Its name comes from the Latin vagus (“the wandering one”)—and that perfectly describes its function: It connects the brain to nearly all internal organs, making it a central hub in the autonomic nervous system.
What the Vagus Nerve Controls
The vagus nerve transmits signals between the brain and the body, thereby maintaining internal balance. It influences numerous vital processes:
- Heart rate and blood pressure
- Breathing and digestion
- Immune responses and inflammatory processes
- Voice quality, facial expressions, and facial movements
About 80% of its fibers carry information from the body to the brain —that is, afferent —while only about 20% carry information from the brain to the body (efferent).
This means that our brain is constantly responding to physical signals—not the other way around.
Two branches, two modes of response
Porges distinguishes between two main systems of the vagus nerve that have evolved:
Ventral vagus:
the “younger” part of the nerve
promotes calm, safety, and social connection
regulates the heart, breathing, and facial expressions
enables communication and emotional resonance
Dorsal vagus nerve:
- “older” portion, found in all vertebrates
- is activated during extreme threat or overwhelming stress
- can lead to withdrawal, exhaustion, or freezing
Both branches work together to determine whether our body reacts in a state of balance, alarm mode, or protective mode.
Connection Between Body and Emotion
A unique feature of the polyvagal theory is the connection between the vagus nerve and the muscles of the face, larynx, and middle ear. This “face–heart connection” allows social signals to directly influence the cardiovascular system. A friendly glance or a warm voice can calm the heart rate and breathing. Conversely, stress can lead to a flat tone of voice, tense facial expressions, or withdrawal. As a result, emotion, communication, and physical regulation become an integrated system—the so-called Social Engagement System.
Why This Is Important
The vagus nerve is not a “relaxation nerve” in the traditional sense, but rather a regulatory nerve. It helps us switch flexibly between activity and rest—depending on what the situation requires.
A well-regulated vagal system means:
better stress resilience
faster recovery after stress
deeper social connectedness
greater emotional stability
This form of nervous system regulation is crucial for mental health and physical balance.
To stimulate the vagus nerve and thereby reduce stress, feel free to watch the following video:
The Three States of the Nervous System According to the Polyvagal Theory
The Polyvagal Theory describes three central states of the autonomic nervous system (ANS) that have evolved over time. These states shift dynamically—depending on how safe or threatened we feel. They form the neurophysiological basis of our emotions, thoughts, and behaviors.
According to Porges and the Polyvagal Institute (PVI), the nervous system has a “built-in monitoring system” that continuously evaluates information about safety or danger based on bodily stimuli and sensory impressions.
This automatic process—known as neuroception—takes place below the level of consciousness.
Neuroception scans people, the body, and the environment for signals of safety or threat. This assessment occurs reflexively and without cognitive involvement. Depending on the result, the body shifts into the appropriate state—connection, activation, or protection. People with high resilience can switch flexibly between these states. In the case of “miscalibrated neuroception,” however, the nervous system reacts with excessive sensitivity to danger—e.g., due to past trauma or chronic stress.
Social Engagement—the State of Safety
When we feel safe, the ventral vagus nerve is active.
It enables social openness, calmness, and communication—the heart beats steadily, breathing is even, and the face and voice appear friendly.
Characteristics:
- Relaxed body language, clear voice, eye contact
- A sense of trust, empathy, and stability
- Activation of the social engagement system, which regulates the heart and facial expressions
Function:
This state lays the foundation for connection and co-regulation:
We unconsciously send out signals of safety, which in turn promote relaxation and openness in others—a biological principle that supports social closeness and healing.
Fight or flight—the state of arousal
When a situation is perceived as dangerous, the sympathetic nervous system takes over.
The body mobilizes energy to respond to the threat.
Characteristics:
- Increased heart rate, rapid breathing, muscle tension
- Alertness, focus on danger, inner tension
- Feeling of alarm, anger, or panic
Function:
This state is essential for survival from an evolutionary perspective—it enables action and protection.
However, if it remains active for an extended period, it leads to chronic stress, irritability, or sleep problems.
Freezing or Shutdown—the State of Overwhelm
When danger is perceived as unavoidable, the dorsal vagus nerve—the oldest part of the system—kicks in.
It slows down all bodily functions to conserve energy and prevent overload.
Characteristics:
- low heart rate, shallow breathing, feeling of numbness
- withdrawal, dissociation, or emotional numbness
- physical weakness or a feeling of faintness
Function:
A defense mechanism in extreme situations—helpful in the moment, but burdensome if it remains chronically active.
In cases of trauma or prolonged stress, the body can “get stuck” in this state—leading to exhaustion or psychosomatic symptoms.
The Interplay of These States
In reality, these states do not occur in isolation but often in combination or in a fluid transition.
The nervous system can create hybrid states that shift between rest, arousal, and protection—depending on the situation and individual past experiences.
The hierarchy follows a clear pattern:
Safety → ventral vagus nerve activated: calm and connection
Danger → sympathetic nervous system activated: fight or flight
Life-threatening situation → dorsal vagus nerve activated: freeze
The goal is not to “stay” in one state, but to switch flexibly between them—Porges calls this ability “neurophysiological resilience.”
Significance for Therapy and Everyday Life with Practical Examples
In psychotherapy, particularly in body-oriented approaches such as Somatic Experiencing or Polyvagal-informed Therapy, knowledge of the various nervous system states serves as a compass: Therapists can recognize whether a person is in a state of safety, alarm, or protection—and respond appropriately. The goal is not to suppress symptoms, but to support a return to a state of inner safety.
This knowledge is applied particularly in trauma therapy to better understand and specifically regulate physical stress responses. This enables those affected to learn to recognize their body’s signals and, step by step, build a sense of inner safety.
This understanding canalso be appliedin everyday life. Those who realize that stress, withdrawal, or feeling overwhelmed are physical reactions to perceived insecurity can learn to gently regulate them. Simple techniques that calm the nervous system and activate the ventral vagus nerve can help with this, for example:
- Conscious, deep breathing
Slow, rhythmic breathing calms the autonomic nervous system. Prolonged exhalation is particularly effective—for example, in a 4:6 ratio (inhalation to exhalation).
This technique lowers the heart rate and stimulates the vagus nerve through the breathing rhythm. Studies show that regular breathing exercises measurably increase vagal activity and reduce stress responses
- Rhythmic Movement or Gentle Stretching
Movement brings the nervous system into balance. Gentle, flowing movements—such as walking, swaying, stretching, or light mobilization—promote rhythmic body awareness and help relieve tension.
This physical rhythm engages deep body receptors and fasciae that are connected to the autonomic nervous system. They support the transition from arousal to rest and strengthen the connection between the body and consciousness
Voice & Humming
The muscles of the larynx, face, and middle ear are directly connected to the ventral vagus nerve.
Humming, singing, or gentle vocalization activates these structures. Just a few minutes a day can calm the nervous system and promote social openness- Mindful Social Contact and Touch
Perhaps the most powerful regulatory factor is co-regulation —the feeling of being in safe contact with another person.
A calm gaze, a friendly voice, or mindful touch signal safety and activate the ventral vagus nerve. In this way, social closeness can literally have a healing effect—both in therapy and in everyday life
In short:
Small, physically perceptible experiences of safety—through breathing, movement, voice, and connection—can realign the nervous system and lead to greater calm, stability, and connectedness in the long term.
Criticism of the Polyvagal Theory:
The Polyvagal Theory is widely applied today in psychotherapy, trauma therapy, bodywork, and coaching. Although it remains the subject of scientific debate, the Polyvagal Theory demonstrates that its strength lies in its practical application: it makes complex neurobiological processes understandable and applicable to therapy and everyday life.
Conclusion
The Polyvagal Theory offers a new perspective on the interplay between the body, emotion, and social connection. It explains that our reactions to stress and closeness are rooted not only in psychology but also deeply in neurobiology. Safety does not arise through thought, but through physically experienced regulation—a central idea that has profoundly transformed modern therapy and coaching approaches.
For many people, the theory provides a clear model for better understanding their own reactions: why we might feel open and connected in some moments—and “shut down” or overwhelmed in others. This knowledge fosters compassion and the ability to gently listen to one’s own body rather than fighting against it.
In both therapeutic and everyday contexts, the future lies in combining science and experience—that is, using insights from neurophysiology, mindfulness, and bodywork to strengthen resilience and self-regulation. The Polyvagal Theory provides a valuable foundation for this: It reminds us that healing begins where the nervous system feels safe—in the breath, in movement, and in genuine, human connection.
FAQ—Frequently Asked Questions
The Polyvagal Theory explains how our autonomic nervous system responds to safety, danger, and threat. It shows that emotions and behavior are closely linked to physical states.
It was developed by the American neurophysiologist Stephen W. Porges, who has been researching the role of the vagus nerve and social safety since the 1990s.
Social Engagement: Safety and social connectedness
Fight/Flight: Activation and protection
Freeze/Shutdown: Withdrawal and survival mode
It helps therapists and clients better understand physical stress and trauma responses and specifically promote pathways to self-regulation and a sense of safety.
Through deep breathing, rhythmic movement, mindfulness, and social connection. These signals calm the nervous system and promote relaxation.
Co-regulation describes the process by which people convey a sense of security to one another through eye contact, voice, or presence. It is the biological foundation for trust and social bonding.
Yes. Some assumptions—such as the precise neuroanatomical separation of the vagus nerve’s components—have not yet been fully empirically substantiated. Nevertheless, the theory is considered relevant to practice and therapeutically valuable because it helps explain complex relationships.
Yes. It is used in many trauma therapy approaches to help those affected understand their nervous system and gradually rebuild a sense of safety in their bodies.
More interesting articles
Sources & Studies
Porges, S. W. (2009). The Polyvagal Theory: New insights into adaptive reactions of the autonomic nervous system. Cleveland Clinic Journal of Medicine, 76 (Suppl 2), pp. S86–S90
Polyvagal Institute (2023). What is Polyvagal Theory? https://www.polyvagalinstitute.org/whatispolyvagaltheory
Neuhuber, Berthoud (2022): Functional anatomy of the vagus system: How does the polyvagal theory align? Functional anatomy of the vagus system: How does the polyvagal theory align? - ScienceDirect