Intergeneration transmission of trauma

How our biology connects us to the past

My great-grandmother (seated), my grandmother (standing) with myself and my brother as small children. My mother is the photographer. © Cynthia Edstrom 2023.

As I watch the horrific events unfold in our world, finding little that I can practically do personally, I find myself thinking about my grandparents, particularly the grandmothers.  What would they think and feel about current events? Would old trauma resurface? Is it surfacing now through my feelings, interpretations, and experiences? What is mine and what is theirs? They were children during WWI and the influenza pandemic. Both grandmothers were brides and young mothers as the Great Depression hit and then they endured WWII in America. Each grandmother responded differently. My paternal grandmother, struggling with mental illness, left her family and children. My maternal grandmother embraced fundamentalist Christianity to set rules for her family, to make sense of things she had little power over, and to hold hope of a better life in the hereafter. 

Although as a young person, I prided myself in transcending my origins and developing thoughts and beliefs I created for myself (so I thought), I am now a bit more humble and aware that much less is under my influence and even less under my control that I believed as a younger person. I find myself surprisingly confronted with evidence that many of my actions are based on unconscious ancestral information.  I’ve written about this regarding body image, weight, and gender issues in other posts. And so, I consider my grandparents and other ancestors and wonder what will show up next.  Their wounds can show up unexpectedly in my longing, or my ambition, or in actions I thought I chose.

As I recognize I have been enacting patterns of my relatives, I can choose to change, choose to observe, or even choose to celebrate their wisdom.  But without awareness, I just reenact family wounds.  I see this same pattern playing out on grand scales in world affairs as centuries old traumas, grievances, suffering, victimizations, and imbedded hatreds out-picture in the actions of governments, groups, populations of people as though harder, stronger hatred and violence could somehow make the wounds of generations go away. As long as we are driven by unconscious patterns, how can we make different choices?  Only once these beliefs become visible, reaching our conscious thinking and heart informed awareness do we have true choice. Even in the absence of aware leadership in the greater world, we still can heal our own families’ wounds and trauma, or at least stop perpetuating them ourselves.  

The concept and understanding that intergenerational transfer of trauma occurs is a recent development.  Documented evidence has emerged in recent years, that the symptoms and behavior of trauma are passed through the generations in ways that are beyond the dynamics of family exposure.  Of course, children pick up things from relatives they know and spend time with.  But evidence continues to emerge that even when a person has no knowledge of a trauma, they still may have symptoms, patterns, or behaviors that reflect that trauma. The knowledge we have was first documented after WWII from studies of descendants of Holocaust survivors and of survivors of war induced famine. And evidence continues to emerge as researchers expand their study to other known traumatized populations such as Native Americans, Indigenous Australians, survivors of earthquakes, descendants of enslaved Africans.  We are affected, profoundly by the experiences of our ancestors whether we know about their circumstances or not¹.  Maybe we’d be wise to learn a bit more about them.

In American popular culture, talk of trauma abounds to the point where the term is beginning to lose its power. But this also indicates a higher awareness that trauma is real and affects people’s lives in important ways. This awareness also opens the way for care and healing.  Out of our emerging understanding of trauma, then, comes this new recognition that our trauma lives on into future generations if unaddressed and unreconciled. 

How does this happen? The short answer is we don’t know, but we know it happens. Intergenerational trauma is an emerging field, super hard to study, but is at least partly connected to the emerging field of epigenetics. And this is what got me thinking and wondering.

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To talk about epigenetics, we must start with DNA. Our understanding of DNA is fairly recent. The double helix structure of DNA was only recognized in the early 1950s. Gene research advanced over ensuing decades as technology improved. Finally, in 2003, just 20 years ago, the human genome was only fully sequenced leading to an explosion of human genetic research, treatments, and even genetic testing for clarifying one’s ancestry and ethnicity. When I was a child 60 years ago, no one talked about DNA. Now it’s slang for what drives us, for what makes us human. How many times have you heard someone say “It’s in our DNA” when they are talking about a deep belief, value, or skill? What’s actually in our DNA is the code or blueprint of information for everything in our bodies – everything from making hormones, to healing wounds, to the neurochemicals that help us think. There is no cellular life without DNA.

Epigenetics arises out of research around DNA.  For a while, we thought that everything about us was contained in the code in our DNA and that things only changed from damage or mutations in DNA².  Now, we are beginning to understand that how our DNA is expressed can be changed by reversible chemical processes, such as methylation, that are activated or deactivated from influences like things in the environment - things such as trauma, or toxin exposure, and probably by positive things like joy and loving relationships. This research area is in its infancy, but the ideas are exciting and already creeping into popular conversation. The discovery of epigenetics suggests that despite the encoded DNA information we are born with, the expression of that code can be adjusted or changed. This opens significant possibilities for human health and well-being (and the occasional sci-fi horror story).

My intention here is not to give a lecture on human genetics, although I love thinking about the stuff. Instead, I’d like to share of my pondering about how people, including myself, get programed to enact something without realizing it. An example of this in my case was my unconscious embrace (or brainwashing) in diet-culture and body image craziness³. How much human conflict in our world is being driven by now outdated encoded messages in our biology, psychology, and general energetics, I wonder?

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And this led me to think about human reproduction and how genetic information is formed and transmitted.  Here’s my quick summary, then I’ll explain in more detail…it boils down to our grandmothers.  

Most of you likely recall from your life science classes that we are formed when an egg and sperm unite forming a fertilized egg. That egg, if lucky, develops into an embryo, then a fetus, and after incubating for about 9 months, we are born as a human baby.  You might also remember that each egg and sperm only contain half the needed DNA to make a human, so they must join together to form the potential that eventually becomes you and me.

Here’s where it gets interesting to me.  In women, every egg (called an oocyte) they will ever have is already present in their ovaries when they are born. They will never make more.  At puberty, through complex hormonal and chemical dances, one egg will be activated about monthly during about 40 or so years of her life. That’s the design. That means that all her eggs formed during while she was inside her mother under the circumstances that her mother experienced during that pregnancy. And the egg that she came from (from her mother’s ovaries) was influenced by what happened to her grandmother. That’s because the mother’s eggs all formed before she was born while inside the grandmother.

Let me give an example to clarify. For a moment, let’s assume you are a woman, a biologic female.  Every egg in your ovaries was formed while your mother was pregnant with you.  If you conceive and have a child, the egg in your body that becomes that child was formed under the influence of your mom’s body during the pregnancy that became you.   And the egg that you came from was formed in your mother’s body while she was still inside your grandmother.  See what I’m getting at? So, every baby human develops from an egg that has been exposed to the two prior generations of women.  Thus, things in my grandmother’s life during her pregnancy with my mother affected the egg that would, years later, become half of my genetic information (the other half coming from my dad’s sperm) that formed the fertilized egg that became the embryo that became me.  Or more simply, the egg that became me was in my mother when she was a fetus in my grandmother’s womb. Trippy to think about. 

Thus, the matrilineage for women is a continuum of biologically connected/exposed generations of threes. 

Daughter/son - mother - grandmother

      Mother - grandmother – great-grandmother

             Grandmother - great-grandmother - great-great-grandmother

                    And continuing ever back ward to the first woman

This deep connection allows for epigenetic and other information to be passed down in a slow, steady way so that survival and safety information remains available through the generations.

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The transmission from the male line is a little different. Sperm is produced by a man’s body beginning at puberty and continuing throughout his life. To make sperm, sperm-potential stem cells go through a process of cell divisions all the time so there are always fresh sperm cells at the ready, unlike the eggs which are neither made nor divide after birth. These sperm have a life span of about three months are less.  This rapid turnover allows for sperm to potentially adjust to the conditions of the moment through epigenetics or other processes.

Sperm develop from stem cells that are formed during fetal life, thus they are informed by conditions the baby boy experienced while he was a fetus inside his mother; thus the experiences of the mother can be transmitted to the son during pregnancy. And the egg the son came from was formed in his mother when she was still inside her mother/his grandmother. Since epigenetic information is alterable, the journey from stem cell to sperm allows for rapid adaptation to the conditions of the life of the man while the slower transmission along the maternal grandmother’s line is also active.

What these observations suggest to me is that we may be profoundly influenced by our grandmothers, both maternal and paternal, in ways embedded in our biology that we may express unknowingly. Of course, we are also affected by the experiences of our father in the weeks prior to our conception and our mother during pregnancy. Perhaps we would be served by knowing more about them…the lives they lived, the circumstances of their times, who they were, the patterns they lived out. 

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Many of us, through popular psychology, self-help, or therapy, investigate our childhoods and the affects our parents’ actions had on us, but we often don’t move beyond recognizing these hurts and perhaps, blaming our parents for difficulties suffered. Similarly, many don’t think about how our grandparents, great-grandparents, and more distant ancestors’ lives may affect the choices we continue to make today, that their experiences may live on in us, even in our epigenetic biology.

The traumas and strengths of women in America’s history have been largely overlooked as our culture focuses mostly on the ‘great man’ explanation of history. I know in my family, we explored the actions of the male ancestors, but knew little about the women. But what if some of the greatest influences on our lives today lie in the trauma and successes of our grandmothers, especially our maternal lineage? If we are unaware, we will continue to enact their fears, avoidances, assumptions, their traumas and coping mechanisms. 

Of course, we are affected deeply by our parents. And we are connected to all our ancestors through our DNA. But we have deeper, bodily connections with our mothers and grandmothers. These connections that begin before we are born are potential deep body resources of wisdom and guidance. But they also are repositories of trauma and despair that we unknowingly enact. Awareness is the only path to choice and change.

What do you know about your grandmothers’ stories? What might they have passed on to you that you enact without knowing, without your conscious consent? What gifts have they given you that you might not recognize?

I certainly don’t share my grandmother’s religious views or her rules about how women should behave. I have been blessed with greater opportunity than she could probably imagine. I don’t think we have to like what our grandmothers did or agree with them or even get along with them.  But becoming aware of their wounds, of the traumas they may be passing down, might be the beginning of healing for one’s lineage. For me, this awareness begins to help me defuse some of the bigotry, fears, envy, and even quiet hatreds that have come down the generations. I can also better honor and celebrate the strengths and gifts they have given me. My life feels better as I realize these things. I feel like I can choose to change. And in a strange way, I feel less alone and more whole.

1. Here’s a good overview on intergenerational trauma and some of the studies that have been done. https://www.apa.org/topics/trauma/trauma-survivors-generations

2. Here’s a more detailed explanation of epigenetics. Here’s another summary from the perspective of psychology. Here’s a definition.

3. I’ve written about this in other posts such as this one about body hatred, and this one about dieting before I was born.