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  • Writer's pictureDr Heather Dyson

The Invisible Threads: Understanding Intergenerational Trauma through Polyvagal Theory & Epigenetics

In the intricate tapestry of human existence, the threads of our past are woven into the fabric of our present. One profound aspect of this historical inheritance is intergenerational trauma — the transference of emotional and psychological wounds from one generation to the next. As we navigate the complexities of our lives, it becomes crucial to explore how the traumas experienced by our grandparents can reverberate through time, influencing our nervous systems and shaping our well-being. In this exploration, we will delve into the realms of polyvagal theory and epigenetics, seeking to unravel the invisible threads that connect the past, present, and future of our mental and emotional landscapes.

Understanding Intergenerational Trauma

Intergenerational trauma is a poignant legacy that transcends time, describing the silent transfer of adverse experiences and their emotional aftermath from one generation to the next. Its roots delve deep into historical events like wars, genocides, forced migrations, and systemic oppression. However, its tendrils also reach into more intimate spaces, entwined with the threads of family dysfunction, abuse, and addiction.

The mechanisms orchestrating intergenerational trauma are intricate, weaving together psychological, social, and biological dimensions. Families weathering profound adversity inadvertently pass down coping mechanisms, relational patterns, and unresolved emotional burdens. This transmission, a subtle dance of inheritance, occurs not solely through explicit communication but also through the nuanced language of non-verbal cues and behaviours. As we navigate our familial histories, it becomes apparent that the echoes of the past are not confined to mere stories; they are an intrinsic part of our present, shaping the contours of our collective well-being.

Polyvagal Theory: Navigating the Autonomic Nervous System

To comprehend the physiological impact of intergenerational trauma, we turn to polyvagal theory, a framework developed by Dr. Stephen Porges. This theory elucidates the role of the autonomic nervous system (ANS) in regulating our responses to stress and shaping our social engagement.

The ANS comprises three branches: the ventral vagal, sympathetic, and dorsal vagal systems. The ventral vagal system, often referred to as the "social engagement system," is associated with feelings of safety, connection, and calm. The sympathetic system activates the "fight or flight" response, preparing the body to confront or escape from danger. The dorsal vagal system, on the other hand, triggers the "freeze" response, leading to immobilisation and disconnection.

Intergenerational trauma can dysregulate the ANS, biasing it toward states of hyperarousal (sympathetic dominance) or hypoarousal (dorsal vagal dominance). Individuals exposed to trauma may find themselves stuck in patterns of chronic stress or dissociation, impacting their ability to form secure attachments and navigate social interactions.

Consequently, when our grandparents experienced trauma, it shaped not only their psychological responses but also the neurobiological pathways through which stress is managed. These adaptive responses, whether hyperarousal or hypoarousal, can be unintentionally transmitted to subsequent generations through genetic predisposition but also through their parenting behaviours towards their children.

For instance, a grandparent who endured the horrors of war may have developed a heightened sympathetic response, always on alert for potential threats. This vigilance may manifest in their parenting style, instilling a sense of constant alertness and reactivity in their children. The grandchildren, in turn, may find themselves grappling with an overactive sympathetic system, predisposing them to anxiety disorders, sleep disturbances, and difficulties in establishing healthy relationships.

Conversely, a grandparent who experienced profound trauma leading to dorsal vagal dominance might struggle with emotional numbness and social withdrawal. The impact on subsequent generations could manifest as a family culture marked by emotional distance and a tendency to avoid intimacy. The grandchildren may find themselves contending with a predisposition to depression, dissociation, and challenges in forming meaningful connections.

Epigenetics: The Genetic Legacy of Trauma

The exploration of intergenerational trauma would be incomplete without delving into the realm of epigenetics — the study of changes in gene expression that do not involve alterations to the underlying DNA sequence. Trauma can leave a molecular imprint on the genes, influencing their activity and subsequently shaping the physiological responses of future generations.

Epigenetic modifications can occur in response to environmental stressors, including trauma. These modifications can be passed down through the germline, affecting not only the immediate offspring but potentially persisting across multiple generations. DNA methylation, histone modification, and non-coding RNA molecules are among the epigenetic mechanisms implicated in this transgenerational transmission.

The Impact of Epigenetics on Mental Health

Within the realm of intergenerational trauma, the field of epigenetics unveils an interesting layer of influence on mental health susceptibilities. Epigenetic changes, alterations in gene expression without modifying the DNA sequence itself, may contribute to the transgenerational transfer of mental health vulnerabilities.

A notable study published in the journal Nature Neuroscience illuminates this intricate connection. In this study, the offspring of rats subjected to chronic stress exhibited discernible changes in DNA methylation patterns associated with stress regulation. Astonishingly, these epigenetic modifications were inherited by subsequent generations, influencing the expression of genes crucial to stress response mechanisms.

In the human context, parallels emerge. The descendants of Holocaust survivors, spanning both children and grandchildren, have been subjects of scientific inquiry. Research has uncovered altered regulation of stress hormones and an increased susceptibility to post-traumatic stress disorder (PTSD) within these generations. These findings underscore the enduring impact of trauma on the epigenome, the dynamic interface between genes and environment.

The implications of such epigenetic changes for mental health across generations are profound. It suggests that the molecular imprints of trauma are not confined to the immediate aftermath but persist, shaping the psychological landscapes of descendants. Recognising the epigenetic dimension of intergenerational trauma invites a deeper understanding of the intricate interplay between biology and experience, emphasising the importance of holistic approaches to mental health that acknowledge the enduring legacy of ancestral wounds. As we grapple with the complexities of mental well-being, this exploration into the epigenetic underpinnings of intergenerational trauma serves as a poignant reminder of the nuanced ways in which our past continues to write itself into our present and future.

Breaking the Chains: Healing and Resilience

While the intergenerational transmission of trauma paints a daunting picture, it is crucial to recognise that the story does not end there. Awareness of these patterns opens the door to intentional healing and resilience-building strategies. Here are some considerations for breaking the chains of intergenerational trauma:

1.     Therapeutic Interventions: Psychotherapy, particularly trauma-focused modalities like Eye Movement Desensitisation and Reprocessing (EMDR) and somatic experiencing, can help individuals process and release intergenerational trauma. Therapeutic interventions provide a space for exploring one's family history, understanding patterns of behaviour, and cultivating healthier coping mechanisms.

2.     Mindfulness and Polyvagal-Informed Practices: Mindfulness practices, such as meditation and yoga, can be powerful tools for regulating the autonomic nervous system. Incorporating polyvagal-informed practices into daily life helps individuals develop a greater awareness of their physiological responses to stress and cultivate strategies for self-regulation.

3.     Community and Connection: Building supportive communities is integral to healing intergenerational trauma. Social connections activate the ventral vagal system, fostering a sense of safety and belonging. Group therapies and communal activities provide opportunities for shared experiences and the cultivation of healthy relational dynamics.

4.     Cultural and Familial Reclamation: Exploring and celebrating one's cultural and familial heritage can be a transformative aspect of healing. By reconnecting with ancestral practices, traditions, and stories, individuals can reclaim a sense of identity and resilience that transcends the shadow of intergenerational trauma.


The threads of intergenerational trauma remain both unseen and enduring. As we embark on the journey to unravel the intricate interplay of polyvagal theory and epigenetics, a profound understanding emerges. It illuminates the ongoing impact of our grandparents' experiences, subtly shaping the contours of our well-being in the present. Integrating this knowledge extends an invitation, urging us to approach not only our personal challenges but also those of our loved ones with a lens of compassion and understanding.

Through intentional healing practices, guided by the wisdom encapsulated in polyvagal theory and epigenetics, lies the transformative potential to break free from the chains of intergenerational trauma. Armed with this understanding, we navigate the delicate dance between the echoes of the past and the unfolding narratives of our lives. This journey empowers us to forge a path toward healing, fostering resilience that transcends the generational imprints of adversity. As we embrace the synthesis of ancient wisdom and contemporary insights, we embark on a quest to liberate ourselves and future generations from the shadows of inherited pain, crafting a narrative that echoes with the resilience of intentional, informed healing.


Photo by Jake Thacker on Unsplash

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