What is Polyvagal Theory?
Updated: Jun 26
Polyvagal theory is a theoretical framework developed by Dr. Stephen Porges to explain the complex interplay between the autonomic nervous system, social behaviour, and emotional regulation. This theory proposes that the autonomic nervous system (ANS), which controls our involuntary bodily functions, has evolved over time to adapt to different environmental challenges and threats.
According to polyvagal theory, the ANS has three distinct branches, each associated with a different level of neurophysiological and behavioural response. The first branch is the unmyelinated vagus, which is responsible for the most primitive and reflexive response to danger, known as the freeze response. This response involves immobilization and shutting down of bodily systems, as a means of conserving energy and avoiding detection by predators. This branch is also associated with the release of certain neuropeptides, such as opioids, that produce analgesia and feelings of dissociation.
The second branch is the sympathetic nervous system, which is activated in response to more immediate threats, such as physical danger or psychological stress. This branch is responsible for the "fight or flight" response, which involves a surge of adrenaline and other stress hormones that prepare the body to either fight or flee from danger. This response can also trigger increased heart rate, rapid breathing, and other physiological changes.
The third branch is the myelinated vagus, which is associated with social engagement and emotional regulation. This branch is unique to mammals, and is responsible for the capacity to connect with others, communicate through facial expressions and vocalizations, and engage in reciprocal social interactions. The myelinated vagus promotes feelings of safety, calmness, and connection, and is thought to play a crucial role in the development of social bonds and attachment.
According to polyvagal theory, the ANS functions in a hierarchical manner, with each branch activated in response to different levels of perceived threat. When we feel safe and secure, the myelinated vagus is active, promoting social engagement and emotional regulation. However, if we perceive a threat, the sympathetic nervous system is activated, and we may experience the fight or flight response. If the threat persists or becomes overwhelming, the unmyelinated vagus is activated, leading to immobilization and dissociation.
Polyvagal theory has important implications for understanding a range of psychological and social phenomena. For example, it can help explain why individuals who have experienced trauma or abuse may have difficulty regulating their emotions, forming social connections, and experiencing a sense of safety and security. These individuals may be more likely to activate their sympathetic or unmyelinated vagus in response to perceived threats, leading to a range of psychological and physiological symptoms.
The theory also sheds light on the importance of social support and connection in promoting emotional regulation and mental health. When we feel safe and connected with others, our myelinated vagus is activated, promoting feelings of calmness and social engagement. In contrast, when we feel threatened or isolated, our sympathetic or unmyelinated vagus may be activated, leading to feelings of anxiety, fear, and disconnection.
Overall, polyvagal theory provides a useful framework for understanding the complex interplay between our autonomic nervous system, social behavior, and emotional regulation. By helping us better understand how our physiological responses to threat and safety are connected to our psychological well-being, this theory has important implications for a range of fields, including clinical psychology, social work, and education.