What Experts Are Learning About Inherited Trauma

  • Lights of rememberance
    Can trauma be passed down genetically?

    Researchers have been studying ancestral trauma—trauma experienced by your ancestors—to understand more about how long-past traumatic events may affect current and future generations. Interest in inherited trauma spiked after people noticed that many of the children of people who survived the Holocaust also experienced anxiety, nightmares, and heightened alertness, even though the children grew up in secure environments.

    The science around inherited trauma is still quite new. Here’s what the experts know so far:

  • Close up hands of old person with Auschwitz concentration camp number showing old Holy Bible to great granddaughter
    Children can be affected by traumatic events experienced by their parents.
    Multiple studies have found that children of Holocaust survivors are prone to worry, guilt and hypervigilance. Compared to others, they are more likely to assume the worst when something negative happens. They also frequently experience anxiety and nightmares.

    Other studies have found similar symptoms in children of Vietnam war veterans. These symptoms often persist through adulthood.

    However, these effects are not found universally in all children of Holocaust survivors or war veterans, and researchers are still trying to understand why some children are negatively affected and others are not.
  • woman sitting in a darkened room using her cell phone
    Inherited trauma may be due to parenting.
    Researchers don’t yet know exactly how ancestral trauma affects subsequent generations. Is trauma passed on genetically—via alterations in DNA—or it passed on socially, via parenting and environmental interactions?

    A service member who returns home from a war with post-traumatic stress disorder (PTSD) may parent very differently than one who never experienced combat. It is possible that children develop hypervigilance, for example, in response to a parent’s ever-changing moods. Or, children may learn hyperawareness from parents who still reflexively scan the environment for threats.
  • Young Lakota girl sits in a tipi and makes a rawhide box
    The trauma of a previous generation may affect the health of their offspring.
    UCLA researchers studying trauma found something interesting when they examined the family trees and health records of Civil War prisoners of war: The sons of Civil War POWs had shorter life expectancies and higher mortality rates than the general population. The sons grew up in peace and plenty, yet their health appears to have been affected by their fathers’ experience of disease, stress and starvation during the war.

    Other studies have revealed that current Lakota people—whose ancestors experienced relocation and starvation—are at increased risk of heart disease and have higher rates of depression than the general public.
  • field of dying maize plants in southern Malawi
    Your grandmother’s exposure to stress may affect your weight.
    The Netherlands experienced a brutal and widespread famine in the winter of 1944. Later studies found that the grandchildren of women who survived the famine were more likely to be obese than would be expected. Further research found that the grandchildren of women who were pregnant that winter were most likely to obese. Researchers suspect that the women’s starvation experience somehow altered the biological makeup of their children, while the children were still in the womb. These changes were then passed on to their offspring.
  • Visiting mom
    Males may be more likely to be affected by inherited trauma.
    When the UCLA researchers looked carefully at the family trees of Civil War POWs, they realized the daughters of POWs did not seem to experience the same adverse effects as the sons. Females born to Civil War POWs lived as long as their peers, while the males’ lifespan was shortened in comparison to their peers.

    Another study found that the male descendants of those who experienced starvation in remote Swedish villages were negatively affected, while female descendants were not.

  • 3D DNA
    Trauma may change how genes act.
    Researchers have found that trauma seems to trigger changes that don’t directly alter or mutate a gene or DNA code, but do influence how the genes act in the body. Known medically as epigenetic changes, these modifications may serve to activate or turn off the gene, which could, in turn, affect the body’s mental and/or physical health.

    Experts have learned, for instance, that traumatized rats have some biological differences compared to non-traumatized rats—and that these rats demonstrate different behavior than other rats. They’ve further proven that these biological changes can be passed down at least six or more generations, influencing the health and behavior of each subsequent generation.
  • researcher studying DNA structure on computer screen next to another researcher looking at brain scans on computer screen
    Epigenetic inheritance of trauma hasn’t been proven in humans.
    A 2018 paper published in World Psychiatry explicitly states, “Studies in humans have not yet demonstrated that the effects of trauma are heritable through non-genomic (i.e., epigenetic) mechanisms.” In other words: Researchers have noted some interesting links between ancestral trauma and the health and well-being of later generations, but they haven’t been able to prove that trauma can be passed down biologically in human beings.

    It’s easier to prove epigenetic inheritance in rats and other animals because scientists can strictly control the animals’ environments. With humans, it’s exceedingly difficult to tease out the effect of nature vs. nurture.
  • African american (black) male teenager in a counseling session
    Inheriting trauma doesn’t mean you’re stuck with it.
    Good news: There are ways to “undo” the trauma of past generations. Researchers have found, for instance, that mice who have been biologically conditioned to fear the smell of cherry blossoms can unlearn their fear, despite generations’ worth of fear of cherry blossoms. And, the UCLA researchers who studied the offspring of Civil War POWs found that even the sons of POWs had healthy lifespans if their mothers had adequate nutrition during pregnancy.

    If you feel weighed down by traumatic events in your family’s past, contact a mental health professional for more information and counseling. Look for a licensed practitioner who has experience working with people with a history of trauma.
What Experts Are Learning About Inherited Trauma | What Is Ancestral Trauma?

About The Author

Jennifer L.W. Fink, RN, BSN is a Registered Nurse-turned-writer. She’s also the creator of BuildingBoys.net and co-creator/co-host of the podcast On Boys: Real Talk about Parenting, Teaching & Reaching Tomorrow’s Men.
  1. Yehuda R, Lehrner A. Intergenerational transmission of trauma effects: putative role of epigenetic mechanisms. World Psychiatry, 2018;17(3), 243-257. doi: 10.1002/wps.20568. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6127768/
  2. Parents’ Emotional Trauma May Change Their Children’s Biology. Studies in Mice Show How. Science. https://www.sciencemag.org/news/2019/07/parents-emotional-trauma-may-change-their-children-s-biology-studies-mice-show-how
  3. The Legacy of Trauma. American Psychological Association. https://www.apa.org/monitor/2019/02/legacy-trauma
  4. Can We Really Inherit Trauma. The New York Times. https://www.nytimes.com/2018/12/10/health/mind-epigenetics-genes.html
  5. ETH Zurich. (2014, April 13). Hereditary trauma: Inheritance of traumas and how they may be mediated. ScienceDaily. Retrieved May 10, 2021 from www.sciencedaily.com/releases/2014/04/140413135953.htm
  6. Shadows of the Past: Epigenetics and Patterns of Inherited Trauma. ICAAD. https://www.icaad.com/blog/shadows-of-the-past-epigenetics-and-patterns-of-inherited-trauma
  7. Inherited Trauma Shapes Your Health. The Atlantic. https://www.theatlantic.com/health/archive/2018/10/trauma-inherited-generations/573055/

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Last Review Date: 2021 May 19
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