In the late 1960s, as the offspring of Holocaust survivors were coming of age, psychiatrist Vivian Rakoff conducted an intensive study in Canada with a small sample group of these adult children. He found high rates of what he called ‘intergenerational trauma’, making the striking observation that it appeared that his subjects, rather than their parents, ‘had suffered the searing, corrupting hell.’ As far as I’m aware, he was among the first to suggest such a thing, and his work served as a prelude to a vast new area of study which would ultimately extend well beyond Holocaust survivors to encompass many other types of traumatic experience.
And yet, the idea that parents’ minds affect their offspring is an ancient one; Wordsworth’s line that ‘the child is father to the man’ reminds us that, well before psychiatry was invented, people understood that our childhood (and how we are parented) shapes how our minds develop as we move through life. But it is only in the late 20th century that researchers began to focus on how brain development might also be affected by parental exposure to trauma, even if it occurred well before our birth.
When I was working as a trauma psychiatrist and psychotherapist in the 1990s, I attended lectures given by Professor Rachel Yehuda, who was looking into how chronic exposure to trauma influences gene expression and levels of resilience, concentrated on the offspring of women who lived through the Holocaust. Her work was my introduction to ‘epigenetics’, the study of the modification of gene expression by different social experiences in the world. Studies were ongoing at that time into the genetic effect of mass starvation on gene expression in infants, for example, and more would follow, exploring how behaviour such as maltreatment, substance misuse and smoking in parents might affect the expression of genes in children.
At no point have researchers found any single genes that affect interpersonal behaviour, and only one or two have been isolated that may increase the risk of mental illness. Genes can only code for the synthesis of proteins, which then affect the synthesis and breakdown of other neurotransmitters and hormones. So, we cannot say of a particular psychological problem that ‘it’s all down to genes’, but we can say that multiple genetic variants interact with other risk factors to increase the risk of a variety of human problems.
It's also essential to consider that children of traumatised mothers – and fathers – may be born along spectrums of vulnerability to stress and resilience. Colleagues in California in the 1990s put forward what they called ‘the dandelion/orchid hypothesis’, exploring how some children might be born with more or less vulnerability than others, which then affected how they responded to environmental challenges, including living with parents who were fighting, addicted or just plain frightened. Most children seem to flourish in almost any conditions – the ‘dandelions’ – while a smaller subset needed more tending, like delicate orchids, and a more enriched environment to develop well. Of course, even the hardiest weed will die if acid is poured over it, and some fragile flowers still thrive under all kinds of stress.
The results of these many studies demonstrate that the old question of ‘nature or nurture?’ is essentially meaningless. Both genetic inheritance and early childhood experience (for good or ill) interact to influence the development of children’s brains and minds. We are also learning that this development process takes longer than we think, and that there are some phases of life (especially the first 4 years and adolescence) when environmental factors are critical for managing stress and distress. As well as genetic expression and variation, we still need to understand more about the role of the immune system, the full impact of child-parent attachment, and the influence of adverse childhood experiences that are hard to quantify, like emotional abuse and neglect.
My new book, UNSPEAKABLE, co-authored with Eileen Horne, is an exploration of the experience of trauma as it is revealed in therapy, in eight case stories based on my thirty years of work as a trauma therapist. We hope to communicate the nuance and complexity of people’s traumatic stress response and the central role of language and identity. Parent-child attachment is a running theme in every chapter, from the story of the young refugee Nadia, whose fear and loss have literally had the effect of rendering her young son mute, to the siblings who experienced abuse and neglect in Irish care homes and speak of their different mental health outcomes. A diverse sample of sometimes tragic but often hopeful stories of discovery and recovery in therapy offers a window into my learning from those courageous men and women who were willing to confront what I call the ‘survivor’s dilemma’ – that it is necessary to speak of the unspeakable in order to move forward.
No doubt there will be more learning – and benefit – ahead from the continued study of trauma and its impacts, especially if we continue to value the unique and intricate nature of each case, and not seek to put people or their painful experiences into boxes indelibly stamped with the word ‘trauma’, as if that experience held one meaning for everyone.
