Intergenerational trauma (or transgenerational trauma) is a unique form of psychological trauma transferred from one generation to the next. In this complex and profoundly impactful process, the children, and sometimes even the grandchildren, of traumatized parents experience negative effects without being directly exposed to the original traumatic event. This concept is better understood as a relational process, conceptualized as the learned or genetic transfer of vulnerability, maladaptive coping mechanisms, and chronic stress responses.

A large portion of the literature on intergenerational trauma has emerged from studies involving the descendants of Holocaust survivors and communities experiencing cultural and historical traumas of Indigenous peoples, such as forced displacement or assimilation policies. These studies have shown that certain symptoms — such as traumatic stress, emotional and psychosocial disorders — can be observed in families affected by historical trauma even three generations after the event occurred. Traumatic effects can become embedded in societal and cultural memory and transferred from parent to child through the same mechanisms that facilitate the transmission of cultural knowledge.

Multi-Faceted Mechanisms Of Transmission

The mechanisms that can cause the transmission of trauma from parent to child encompass biological, psychological, and social domains:

1. Attachment And Relational Impairments

The attachment relationship is a critical channel that either causes or prevents the transfer of trauma between parent and child. Parents who have failed to integrate their past traumatic situations into consciousness, meaning their traumas remain unresolved, transfer this unresolved state to their children through specific interaction patterns.

Caregivers who have faced trauma often struggle to provide consistent, sensitive, nurturing, and responsive care. Exposure to trauma increases parental anxiety and heightens the risk of a dysfunctional parent-child relationship.

This transmission often results in insecure, disorganized, or avoidant attachment styles in the child. This disorganized attachment lays a foundation that makes the child more vulnerable to future traumas and stressors. The emotional unavailability of the parent and a reduced capacity for mentalization (the ability to understand the mental states of oneself and others) are key to relational transmission.

2. Biological And Epigenetic Processes

Intergenerational trauma transmission also occurs through potential biological pathways. Research into these pathways — including neuroendocrine, neuroanatomical, and epigenetic changes (heritable changes that affect gene expression without altering the DNA sequence) — is growing.

Chronic stress and trauma exposure can alter the gene expression of parents, and these changes can affect the structure and function of the developing brains of their offspring. This can lead to the transmission of fear, hyper-alertness, and vulnerability to PTSD, fundamentally undermining the subsequent generation’s ability to cope with challenges.

3. Maladaptive Communication And Parenting Styles

A parent’s trauma experience can lead to intrusive, hostile, or rejecting parenting behaviors. Widespread silence about traumatic experiences in family communication can cause trauma to be perceived as an incomprehensible burden, while excessive and unfiltered discussion can also be damaging to the child.

The child, observing the parent’s responses to trauma, may incorporate these reactions into their own coping repertoire.

Risk And Protective Factors

In high-risk groups, specific factors significantly influence whether trauma will be transmitted.

Risk Factors

• Level of parental trauma: The severity of PTSD symptoms in the mother or father is directly related to negative outcomes in children.

• Relational impairments: Insecure, anxious attachment representations, rejection, and role reversal between parent and child (such as the child caring for the parent) are identified as co-variables of transmission.

• Familial stress: The accumulation of stressors (financial difficulties, immigration concerns, marital conflict), impaired family functioning, and the child’s direct exposure to trauma (e.g., neglect due to parental substance use) are major risk factors.

Protective Factors

• Family strength: High family resilience and adaptability are significant protective factors.

• Social support: Perceived strong support systems and broad social networks reduce psychological distress and the risk of PTSD in children.

• Parental functioning: Educational levels, consistent parenting practices, and general parental stability can mitigate trauma effects.

• Modulated communication: Open, balanced, and intentional communication about traumatic events helps children integrate the experience and reduces risk.

Prevention And Intervention

Current research agrees that preventing the transmission of intergenerational trauma is the most effective intervention approach. Intervention strategies should focus on both helping the parent resolve their own trauma and strengthening the parent-child attachment relationship.

Helping the parent integrate their trauma history into a coherent self-narrative and increasing their mentalization abilities are key to breaking the cycle by supporting the child’s emotional regulation skills.