Human connection is not only emotional or psychological, but is also profoundly biological. Beneath every interaction lies a complex web of physiological responses orchestrated by the nervous system. Understanding how this system functions, and how it is shaped by trauma and healing can transform the way relationships are experienced.
The Nervous System – The Hidden Partner in Every Relationship
Every relationship involves two nervous systems in constant communication. Smiles, tone of voice, body posture, and eye contact all act as cues that the body interprets long before the conscious mind has time to respond.
According to Dr. Stephen Porges, founder of Polyvagal Theory, the autonomic nervous system continuously evaluates the environment through a process called neuroception. This is an unconscious mechanism that detects safety, danger, or threat. This detection occurs automatically, influencing how humans feel and behave toward others.
When safety is sensed, the ventral vagal complex, known as the social engagement system becomes active. In this state, the heart rate slows, breathing deepens, and connection feels natural. When the nervous system perceives danger, it shifts into sympathetic activation (fight or flight), preparing the body for defence. In moments of overwhelming threat, it may collapse into dorsal vagal shutdown (freeze), leading to numbness or withdrawal.
The nervous system can be said to be the hidden partner in every relationship. It shapes communication, emotional tone, and controls our ability to stay present or can force us to retreat during conflict.
Trauma and the Rewired Nervous System
Trauma profoundly alters the functioning of the nervous system. Experiences of threat, neglect, or loss can leave lasting imprints that distort the body’s sense of safety.
Dr. Bessel van der Kolk, in The Body Keeps the Score (2014), describes trauma as the body continuing to defend against a threat long after the danger has passed. The nervous system, once adaptive, can become stuck in patterns of hyperarousal or shutdown.
The result is a system that misreads the present moment through the lens of the past. For example:
- In sympathetic activation (fight or flight), the body stays alert and tense, ready to fight or flee. Relationally, this may appear as defensiveness, control, or irritability.
- In dorsal vagal shutdown (freeze), energy collapses, and connection becomes difficult. Numbness, withdrawal, or dissociation may occur.
- In ventral vagal safety, regulation allows for openness, curiosity, and intimacy.
Trauma can make safety feel unfamiliar, even threatening. Genuine affection may be misinterpreted as danger because the body has learned that closeness leads to pain. Dr. Peter Levine, developer of Somatic Experiencing, notes that “trauma is not what happens to us, but what we hold inside in the absence of an empathetic witness.” The body holds those unprocessed experiences, shaping how individuals respond to others.
When the Body Reacts Before the Mind
Reactivity in relationships is often a nervous system response, not a moral failure or character flaw. The body moves first before rational thinking can step in.
A raised voice, a sigh, or a turned back can trigger a physiological cascade, causing the heart to race, muscles to tense and breathing to become shallow. These responses occur before conscious reasoning can intervene. The nervous system reacts as though there is danger, even when the threat is emotional rather than physical.
This can be seen as the invisible lion response, when the body reacts to a partner’s tone or expression as if a lion has entered the room. The survival system hijacks behaviour, leading to arguments, avoidance, or emotional collapse.
Recognising this mechanism does not excuse harmful behaviour, but it provides essential context. Understanding that reactivity originates in the body allows for compassion and creates the conditions for regulation and repair.
Healing Through Regulation
Healing from trauma requires more than intellectual insight. It involves retraining the nervous system to experience safety again. Regulation occurs when the body regains flexibility and the ability to move between states of arousal and calm without becoming trapped in either.
The process of healing involves bringing the body’s alarm system back into the present time. This can be cultivated through several approaches:
- Awareness: Learning to notice bodily sensations such as tightness, heat, tension, and numbness without judgment. Awareness transforms unconscious reaction into conscious observation.
- Co-regulation, where safety can be restored through connection. The presence of another calm, regulated person can signal to the nervous system that it is safe to settle.
- Self-regulation, involving techniques such as grounding, slow breathing, mindful movement, and gentle stretching that can calm physiological arousal.
- Integration through repeated experiences of safety. This can cause new neural pathways to form, and the nervous system begins to associate connection with calm rather than danger.
Body-based therapies and polyvagal-informed approaches are designed to support this process. Van der Kolk’s research demonstrates that modalities involving bodily awareness like yoga, EMDR and breathwork, can restore regulation more effectively than talk therapy alone, as they communicate directly with the nervous system’s language.
Relationships are Healing
Healing the nervous system often occurs within relationships, not apart from them. Connection can provide the biological conditions for safety, and safety allows the body to process and heal.
Co-regulation is the foundation of this process. When one person maintains a regulated state, displaying a calm voice, relaxed posture and steady breathing, it can help another person’s system stabilise. This is the same mechanism by which infants learn security from caregivers.
Conflict can therefore become fertile ground for transformation. When a partner recognises that a reaction is physiological rather than personal, the conversation can shift from blame to awareness. Emotional regulation allows for repair, understanding, and connection.
Healing is not about never being triggered again or developing completely porous or rigid boundaries. It is about knowing what to do when activation arises. Regulation creates space between reaction and response, allowing us to choose how we react in difficult moments.
From Reaction to Relationship
By understanding that the nervous system affects our emotional responses, reactions that once appeared irrational or excessive are revealed as survival strategies learned in the body’s past. This perspective replaces judgment with curiosity and shame with compassion.
When the nervous system is regulated, relationships become safer and more authentic. Communication deepens because both individuals can remain present rather than defensive or withdrawn. Regulation allows for empathy, patience, and trust, which are all important in relational healing.
Trauma may shape the nervous system, but it does not define it permanently. Through awareness, co-regulation, and therapeutic support, the body learns that connection can coexist with safety. A nervous system which was once a guardian of survival can become a gateway to intimacy and peace.
References
Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. W. W. Norton & Company. https://pmc.ncbi.nlm.nih.gov/articles/PMC3490536/
van der Kolk, B. A. (2014). The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. Viking. https://ia601604.us.archive.org/35/items/the-body-keeps-the-score-pdf/The-Body-Keeps-the-Score-PDF.pdf
Levine, P. A. (1997). Waking the Tiger: Healing Trauma. North Atlantic Books. https://cmc.marmot.org/Record/.b10953930
Porges, S. W. (2022). “Polyvagal Theory: A Science of Safety.” Frontiers in Integrative Neuroscience. https://www.frontiersin.org/journals/integrative-neuroscience/articles/10.3389/fnint.2022.871227/full
