Intergenerational transfer of trauma

Children inherit trauma from their parents. How can it be resolved?

“If you aren't willing to face your demons—if you can't find the courage to take on your fear and hurt and anger—you might as well wrap them up with a bow and give them to your children. Because they will be carrying the same thing... unless you are willing to do the work.”

― R.A. Dickey, Wherever I Wind Up (2012)

Photo by Keren Fedida on Unsplash

Inherited trauma

Psychologists have long recognized that children of parents with post-traumatic stress disorder (PTSD) exhibit behaviors and experience feelings consistent with their parents’ trauma. For example, studies of Holocaust survivors’ children have discovered that they “present symptomatology and psychiatric features that bear a striking resemblance to the concentration camp survivor syndrome” (Borocas & Borocas 1979). That is, the children are exhibiting characteristics of the parents’ PTSD, even without having the traumatic experiences themselves (e.g., Yehuda et al. 1998).

Current explanations of intergenerational transfer of trauma in psychology rely on theories of learned behavior, in which children imitate and habituate the observed responses of their parents to emotional triggers. For example, psychologist Judith Alpert, PhD writes:

“I always knew that something terrible had happened to my mother. She was afraid of everything. She was afraid of dogs. She was afraid to stay alone. Lights had to be on at night, even when we were sleeping. Lurking strangers must be seen or frightened away. She was afraid of men she did not know. When there was a delivery, she would tell me to hide under the bed until he was gone. And when she opened the door to these unfamiliar men who delivered our groceries, she concealed a knife in her pocket, ‘just in case’ ” (Alpert 2015).

Growing up under circumstances such as these, it makes sense that a daughter modeling her mother’s behavior would internalize the lesson that the world is a dangerous place.

For example, Alpert writes “I had a lot of my mother’s terrors. I was afraid of dogs. I was afraid of men and I was sometimes even afraid of my father.”

However, in Alpert’s own biographical accounts, she describes no physical, sexual, or emotional abuse. To the contrary, she describes a loving familial environment with strong ties to extended family, and a supportive parents. In this context of diverse and positive role models, it is difficult to imagine that observing her mother’s phobias alone would play such a driving force in Alpert’s development.

Learning-based theories also fail to explain the extent and depth of symptoms experienced by children of traumatized parents described in several other studies. And they overlook Alpert’s own intuitions that the intergenerational transfer of trauma is more than merely psychological. She writes, “The child doesn’t have to experience the parent’s trauma for the child to imagine how these events happened and for these imaginings to become the content of unconscious fantasy.”

Epigenetic inheritance of ancestral trauma

In The Genetic Self: Epigenetics I wrote about how experiences modify the epigenetic encoding of DNA in ways that will switch on or off genetic expressions. For example, rats that have been traumatized by electric shocks, and conditioned to associate these shocks with a certain odor, will experience methylation of their DNA to switch off genes that drive exploratory behaviors. Thus, their trauma has a measurable material embodiment within the nucleus of their cells.

Moreover, that epigenetic adaptation is passed down to the pups such that their DNA is methylated in the same way as their parents. In the absence of any experience with electric shock, or with odor, rat pups born to the traumatized parents exhibit the same fear response to the same odor that the parents were conditioned to fear.

Thus, the junior rats inherited the trauma in epigenetic adaptation, not by observing the mother rats respond to exposure.

The mechanisms by which modified genetic expression might manifest in certain behaviors are complex and thus difficult to decode. Nonetheless, the children of Holocaust survivors with PTSD exhibit chronically lower cortisol levels than children of parents in a control group with Holocaust exposure, absent PTSD (Yehuda et al. 2000). Additionally, more recent research has revealed that low cortisol is associated with failure to respond to treatment therapies for PTSD (van Gelderen et al. 2020). That is, among a group of military veterans suffering from PTSD, those with higher cortisol levels responded better to treatment than those without. In fact, administration of cortisol prior to exposure therapy sessions improves the effectiveness of the therapy and speeds resolution of symptoms (Aerni et al. 2004, Merz et al. 2018).

This suggests that one mechanism by which epigenetic adaptations in children might modify stress response is in genomic regulation of hormones active in the hypothalamic–pituitary–adrenal (HPA) axis that governs the autonomic nervous system. In other words, inherited epigenetic adaptations could prime children for biochemical responses to certain stress exposures that are analogous to those experienced by their ancestors. Such priming would be an evolutionary advantage if it prepared children to survive and reproduce in a threat environment that was similar to their parents’, but would function as maladaptive in environments that no longer exhibit that threat. Thus, the biochemical adaptations that served the survivors of the Holocaust during their horrific experiences would be detrimental to their descendants.

The body knows what the brain can only imagine

Alpert has spent 40 years studying trauma—in particular “sexual violence against women in wars, genocide, in the military, in the family, and in schools and other institutional settings” (Alpert 2016). Her entire professional life has been organized around seeking to understand and heal women who have had experiences Alpert has not.

According to Alpert, unresolved trauma became an “unconscious organizing principle” in her life. Although the epigenetic inheritance of acquired characteristics seems unknown to her, Alpert reveals a keen intuition when she writes “(Unresolved trauma) is like a genetic disease in that those victims, perpetrators, or even witnesses who are distant in the future may be affected.”

Perhaps through her professional training and her own experiences in pyschoanalysis as an adult, Alpert came to “know” she carried the embodied trauma of her mother and her grandmother, but it wasn’t until her mother was 87 years old that the explicit knowledge Alpert had been seeking for decades was finally revealed to her.

After five days keeping vigil beside her death bed, Alpert’s mother finally confessed “I was raped by the dress shop owner when I was 15.”

And then she died.

Alpert wrote “Although she had never told me this before, once she told me I knew that she had told me what I had always known.

“Although she did not tell me in words, my mother was not silenced. Her behavior spoke… . She spoke but not with the language of the conscious, coherent speech… . Of course I knew. Of course she knew. It is my impression that she always had conscious memory and that she used dissociation to manage the flooding of affect and the overwhelming flashbacks she experienced. When she saw fears being played out in me, she took action. She put us both in treatment. She stopped the intergenerational transmission of trauma.”

Resolution of inherited epigenetic trauma

Alpert entered therapy when she was five years old.

“My therapist and I had an invisible war to engage in which appeared to be linked to my mother’s trauma and my grandmother’s trauma. My internal house was haunted, and my five-year-old fears were linked to their unresolved emotional shocks and loss.”

Alpert’s most vivid memories of her therapy are playing with toys, rather than talking with her therapist.

Play is a long-standing biological mechanism by which juveniles attempt to resolve trauma. Like the cheetah cubs who survived the lioness attack that Peter Levine describes in Trauma and Memory (2015), and the little girl who plays doctor with her dolly after receiving her shots that Laurence Cohen describes in Playful Parenting (2002), as a child Alpert was replaying the trauma carried in her epigenome during her therapy.

Nonetheless, she had no explicit knowledge of the source of the fantasies that intruded on her child mind.

According to Alpert, “Unresolved traumas get handed down to children, and these hand-me-downs are too massive for them. It is confusing and scary. There are strong reactions to things that cannot be seen or understood. The child needs to know. At the same time, mother needs to not know.”

While the cheetah cubs and Cohen’s little girl both had conscious memories of the experiences they were attempting to relive from a position of control in their play, as a child Alpert could not have had any awareness of her behavioral compulsions, and consequently she could only make sense of it decades later, as a grown woman with professional, specialized training in sexual trauma in the context of genocide. It was in this genocidal context of the Odessa pogroms that Alpert’s Jewish grandmother experienced her own trauma, that was subsequently passed down to and compounded by her mother’s rape as a teenager.

But Alpert knows of her grandmother’s experiences only by inference, not by her grandmother’s direct testimony — a degree of ignorance that must frustrate the children of traumatized individuals who lack Alpert’s training.

Because epigenomic adaptations respond to experience, the way to erase inherited trauma is to create new experiences that resolve the inherited trauma from a position of control. But how should the child of a parent with PTSD undertake to resolve a trauma about which they have no conscious knowledge of the circumstances?

There can be no other alternative for parents, but to share the memory of their traumatic experiences with their children, as Alpert’s mother eventually did.

This point is underscored by the R.A. Dickey quote in the epigraph about dealing with your trauma, or handing it down to your kids. The quote is drawn from Dickey’s memoir about confronting his history of childhood sexual abuse (Dickey 2012).

While Dickey’s parents shared little, if anything, or their own trauma histories, his healing journey was motivated by interrupting the intergenerational transfer of his trauma to his own children.

For Dickey, revealing the truth about his trauma to his children is part of that process, perhaps because it is not practical for a child to undertake decades of analysis as an adult, in the hopes of making inferences and discoveries of the secrets that the parents might wish would die with them. The trauma has already been passed on, and its resolution will be accelerated when the child is aware of the circumstances that created it — at least in ways that are appropriate to how children might comprehend at their age.

For an example, see Dickey’s children’s version of his memoir (Throwing Strikes, Dickey 2013) in which he includes a chapter describing his sexual abuse designed for children 8-12 years old.