Polyvagal Theory is a way of understanding how our nervous system responds to different situations, like stress, danger or safety. It was developed by Dr. Stephen Porges, a neuroscientist and psychologist, in 1994. In simple terms, Polyvagal Theory helps us understand how our body and brain work together to respond to stressors that are a part of everyday life as well as experiences that are more significant, such as trauma.
 

According to the theory, our nervous system has three main response states, or "branches." The first is the "fight or flight" response, which is activated when we're in a dangerous or threatening situation. Termed ‘mobilization’ in Polyvagal Theory, this is our body's way of preparing to either fight the threat or run away from it.

The second response state is the "collapse” response, which is activated when we feel overwhelmed or powerless. In this state, our body shuts down and we may feel numb or disconnected from our surroundings. In Polyvagal Theory, this is called ‘immobilization.’ The third response state is the "social engagement" response (termed ‘ventral vagal’ in the Theory), which is activated when we feel safe and connected to others. This is when we are relaxed and open to social interaction, and is communicated in our eyes, facial expressions, and tone of voice.

These three states are not entirely separate but rather a continuum through which we move on a daily basis. Although the three states are controlled by different parts of our nervous system, they are all directly managed by the vagus nerve. The vagus nerve is a large nerve that goes from the base of the brain to the gut, connecting the brain to the body. The vagus nerve plays a key role in regulating our heart rate, breathing, and digestion, as well as our emotional state.
 

Polyvagal Theory suggests that by understanding the fluctuation of these different response states, we can better manage our own health and wellness and better understand the behavior of others.