Abstract
This research paper explores the complex and challenging topic of intergenerational trauma in the Indigenous populations of what is colonially known as Canada. The main focus of this paper is on the historical sources of trauma resulting from colonization and on how trauma is passed down from one generation to the next to continue affecting people who never experienced the original traumatic event(s). Utilizing research sources and articles from both Indigenous and non-indigenous sources, this paper explores how epigenetics, disrupted family dynamics, and cultural losses play a role in perpetuating this trauma and making future generations more sensitive to trauma. I will explore how the trauma experienced by past generations continues to affect the Indigenous people of today, making them further susceptible to negative effects of current traumatic events. Furthermore, this paper emphasizes the critical role of Indigenous-led healing initiatives, as well as culturally appropriate interventions, in fostering resilience and promoting reconciliation.
Purpose Statement
As a counselling therapist, I have a strong interest in the multifaceted nature of trauma and its underlying mechanisms. I chose this topic because I believe that more work needs to be done to understand trauma and how it changes our biology, sometimes permanently, and the way we interact with the world. This research into intergenerational trauma and its specific effects on Indigenous populations in Canada is essential to my professional development as a future social worker. By exploring the ways in which historical and intergenerational trauma continues to influence the worldviews, behaviors, and well-being of Indigenous people, I aim to cultivate greater empathy, cultural humility, and the competence in my practice to ultimately provide more effective and culturally sensitive support.
Limitations and Scope
I acknowledge that as a white European person who was not born on these lands, that I am an outsider and an uninvited settler and that my perspective is influenced by these factors. I am aware that no matter how much I learn and attempt to address my internal biases, they will always exist to a certain extent. Lastly, I acknowledge that as much as I can try to understand the experiences and culture of the Indigenous people of this region, I will never be able to understand things from a place of lived experience. It is important to acknowledge these factors and limitations.
Note: In this paper, I refer to Indigenous people of Canada with full awareness that there are many nations, tribes, and communities within Canada and that not all Indigenous communities or nations are the same. They are each unique with their own traditions and cultures, but they have all suffered similar trauma at the hands of the white European settlers and from colonization and colonialism. I consciously include Inuit, Metis, and First Nations peoples when mentioning the Indigenous people of Canada in this paper.
Introduction and Background
Intergenerational trauma is a serious phenomenon which has affected Indigenous populations all over Turtle Island (North America), mainly due to the harmful effects of colonization as well as the harms of oppressive systems such as the residential school system in Canada and the resulting genocide of the Indigenous peoples. For this research paper, I will be focusing on the intergenerational trauma of the Indigenous peoples in Canada, and not the whole of Turtle Island (North America). While the harmful effects of intergenerational trauma have been known for decades, it is only since the mid-1990s that we are starting to fully understand the concept of historical trauma (Gone et al., 2019) and our increased focus of epigenetics is even more recent. This research paper will examine how historical trauma experienced by Canadian Indigenous peoples, specifically through the forced suppression of native languages and loss of traditional practices within the residential school system, can be transmitted across generations through genetic, epigenetic, social, psychological, and cultural pathways.
In an article by Elias et al. (2012) it is stated that, “Intergenerational trauma is the theory that a trauma that is experienced by one person in a family—for example, a parent or grandparent—can be passed down to future generations because of the way that trauma epigenetically alters genes.” Some of the main sources of trauma for Indigenous peoples in what is called Canada were colonization, the residential school system, and being forced onto reservations which restricted their freedom, culture, and enjoyment of the lands that they had occupied for many generations before that. The traumatic events experienced by Indigenous people in Canada have harmed not only those who directly experienced them but also their children, grandchildren, and future generations. The evidence shows that the intergenerational transmission of trauma makes future generations more likely to experience addictions, sleep disturbances, emotional dysregulation, and other signs of PTSD even in people who did not experience the initial trauma (Valeii, 2024).
Colonization in Canada started in 1608 with a French settlement in Quebec, and then the British influence started around 1670 with the creation of the Hudson’s Bay Company (Hele, 2023). According to an article by Elias et al. (2012) about trauma and suicide behaviour histories among Indigenous people in Canada, the authors state that “As early as 1892, indigenous children were removed from their families and communities and sent to schools operated by the Roman Catholic Church, Church of England, United Church, or Presbyterian Church, and later by the Government of Canada.” Considering that the last residential school closed in Canada in Saskatchewan in 1996 (Peterson, 2020), this means that the residential schools and the harms they inflicted went on for over 100 years and spanned multiple generations of children being taken from their families.
Many sources of trauma for Indigenous people can be traced back to racism, racial prejudice, greed, and discrimination at the hands of the white European colonizers. Racism, racial prejudice, and greed are widely accepted as the motivations for the residential school system and other policies implemented by the Indian Act of 1763. To this day, many Indigenous people face racial prejudice and racial discrimination at the hands of the police, healthcare workers, and businesses. These are all going to be significant sources of trauma for Indigenous people and are then passed down through generations by social, environmental, and biological factors.
Historical Trauma and Colonization in Canada
Historical trauma for the Indigenous populations began with the colonization of what we know as Canada by the white European settlers and escalated with the opening of the first residential school in Ontario in 1831. Some examples of historical trauma for Indigenous people were being forced onto reservations, the creation and enforcement of the pass system, the residential school system, the sixties scoop, and the missing and murdered indigenous women and girls (MMIWG).
In 1885, the creation of the “pass system” required indigenous people to acquire a pass just to leave the reservation that white people had forced them to live on (Peterson, 2020). This system would have caused trauma alone with basically confining Indigenous people to a small patch of land and requiring them to get a pass just to leave that piece of land for any reason. The pass system went until it was repealed in 1951; a stretch of 66 years (Peterson, 2020). The government used this method to shut down many cultural celebrations, including potlatches, and to force Indigenous people to conform to the traditions and habits of the white colonizers (Peterson, 2020).
Another way the government suppressed Indigenous culture was the residential school system which was largely run by the Catholic and Anglican churches with the aim of assimilating the Indigenous population through their children. The stated objective of these schools was to “kill the Indian in the child” (Peterson, 2020). This was carried out by mandatory attendance and enforced by the RCMP and social workers. It is estimated that 150,000 children attended the residential schools, and over 6,000 children died while attending those schools (Peterson, 2020) but exact numbers are unknown because records were incomplete. Many Indigenous organizations disagree with these very conservative estimates, especially of the deaths in the schools. Indigenous children were also used for experiments without consent and for research while attending these schools (Matheson et al., 2022; Peterson, 2020). This further proves that the government, and especially the residential schools, did not see Indigenous people as humans capable of feeling pain.
Another historical trauma is what has come to be known as the “sixties scoop”, and was a mass “scooping up” of Indigenous children to be taken to residential schools or placed with white families under the belief that Indigenous people could not effectively look after their own children. The term “sixties scoop” was first used by Patrick Johnson in a 1983 paper about Indigenous children in the child welfare system (Baswan & Yenilmez, 2022). This historical trauma caused a mass amount of disrupted attachment, negatively impacting the children’s “ability to connect with their families when they did return home” (Peterson, 2020). The sixties scoop also disrupted the ability of indigenous communities to pass down knowledge and traditions to their children which has had a traumatic impact on Indigenous culture and traditions to this day.
The instances of missing and murdered indigenous women, girls, boys, and men has been an ongoing issue and another source of historical trauma for the Indigenous people in Canada. In 2019, a report was issued by the National Commision which was created for this purpose. The MMIWG crisis refers to the fact that Indigenous women and girls (as well as 2SLGBTQSIA+ people) are more likely to go missing or be murdered, especially in rural areas such as the Highway of Tears in Northern British Columbia. Another issue around this is the severe under-reporting of these instances which leads to a large discrepancy of numbers for Indigenous women and girls who have gone missing since 1980. This issue is ongoing as of 2025 and has sparked many campaigns including the Moose Hide Campaign for awareness of gender-based violence, and the Red Dress campaign for awareness of the MMIWG.
Matheson et al. (2022) states that “While there has been a focus on direct acts of genocide, less often has consideration been given to the indirect impacts involving trauma, poverty, food scarcity, forced migration, loss of homes and land, loss of cultural values and overall impacts on health and well-being.” This is a good point, because there are indirect impacts of trauma that deserve just as much consideration when looking at historical trauma of Indigenous people of Canada.
The Intergenerational Transmission of Trauma
Trauma can be transmitted, or carried down, through generations in multiple ways. These include biological, environmental, and social transmissions of trauma.
Biological Transmission (Epigenetics)
According to research by Orton et al. (2023), “Epigenetics is often defined as heritable changes in gene expression, without changes to the sequence of the DNA” and the author goes on to describe how transmission of epigenetics is called epigenetic inheritance. The article also explains epigenetics as “Epigenetic modifications are alterations in deoxyribose nucleic acid (DNA) that do not change the DNA sequence but regulate which genes are expressed” (Orton et al., 2023). The science of epigenetics has been known since the mid 20th century, but more research into epigenetics and trauma has only been happening in the 21st century. This has not given many studies enough data to work with because of the relatively short time frame since epigenetics gained momentum. The most commonly studied type of epigenetics is a process called DNA methylation, “which involves the addition of a methyl group to cytosine residues” (Orton et al., 2023), and shows how trauma can change a person’s biology, and potentially their reaction to future traumatic events, without actually altering DNA. This process allows our body to encode traumatic events into our biology, which, in theory, allows future generations to benefit from anything the trauma would have taught past generations. This could theoretically explain how some cultures are wary of white people even if they have never met a white person themselves because it is written into their DNA from past generations. Epigenetic changes, once thought to be infrequent, are now known to be extremely frequent, with some changes being permanent and others transient (Matheson et al., 2022). There are also increasing links between epigenetic changes resulting from trauma affecting physical health outcomes (Matheson et al., 2022).
During the developmental years of childhood and adolescence, any trauma experienced leaves a distinct biological effect on the brain’s development, including the amygdala, hippocampus, and prefrontal cortex (Laricchiuta et al., 2023). In the journal article entitled “The Body Keeps the Score”, Laricchiuta et al. (2023) mention that humans, having “the slowest rates of brain development of all species, needing years to reach maturity,” are more vulnerable to the harmful effects of trauma during developmental years." Indeed, the article also mentions that “Living with a history of chronic trauma or experiencing exposure to acute trauma during the development may have different, and sometimes even more pronounced, effects on the brain/body than trauma exposure occurring in adulthood” (Laricchiuta et al., 2023). This could mean that trauma experienced during childhood and adolescence has a higher impact on the brain and biology than trauma experienced after maturation to adulthood.
When discussing how little research has been done on how traumatic events could induce intergenerational epigenetic changes, Matheson et al. (2022) state that “In part, this lack of research is not surprising given the numerous instances in which Indigenous Peoples have been experimented on without consent, lied to about the goals of research, and over-researched while at the same time remaining invisible in research.” Additionally, the author expresses that “there is a concern that genetic research might be used to undermine the responsibility of colonial governments to acknowledge the causal role of history in relation to health inequities” (Matheson et al., 2022).
Environmental and Social Transmission
Other ways that trauma can be transmitted to future generations are environmentally and socially. Environmental transmission of trauma can be witnessing traumatic events such as children witnessing domestic violence between parents, or low socioeconomic status. Social transmission of trauma can be patterns of abuse or neglect which are passed down as a result of various mental health conditions in parents.
A simple example of the social transmission of trauma is the common saying, “hurt people hurt people,” which means that people who have experienced trauma may, in turn, hurt others due to maladaptive coping mechanisms or a lack of emotional regulation ability. Mental health conditions are one of the biggest causes of the social transmission of trauma due to neglect or abuse, which then in turn causes mental health conditions in the children.
When it comes to the transmission of intergenerational trauma, an article by Elias et al. (2012) states that “Life trajectories of survivors of mass trauma have been well documented amongst holocaust survivors” but that we have less documentation and research into the life trajectories of residential school survivors. It is my opinion that this could highlight some racial disparity between how trauma is treated in European populations versus Indigenous populations of Canada, and the whole of Turtle Island. The article also states that “While research shows that trauma and traumatic experiences are just as highly prevalent in both indigenous and non-indigenous populations, the multigenerational implications of trauma are thought to be greater within indigenous populations since a higher proportion of the population was affected by a large-scale and sustained traumatic exposure” (Elias et al., 2012). This, to me, implies that more focus is necessary on the issue of intergenerational trauma in Indigenous people in Canada.
Looking Toward Resilience and Healing
When looking toward the possibility of healing a population from the effects of trauma, we must first look at whether trauma is still ongoing. In many Indigenous communities, it still is. For example, there are communities of Indigenous people without access to clean running water, and many Indigenous people are at a higher risk of addictions, mental health conditions, and suicidality because of the traumas they have faced (Valeii, 2024). So, if trauma is still ongoing, then it makes healing from the trauma more difficult. If someone is still experiencing trauma, then can they reasonably be diagnosed with post-traumatic stress disorder (PTSD)? If the trauma is still ongoing then the natural step is to attempt to stop the sources of trauma before effective healing can begin.
Gone et al. (2019) states “Resilience is the ability to thrive despite experiences of adversity or trauma.” This is an important concept, especially when looking at Indigenous Historical Trauma (IHT), because “resilience can be conceptualized in collective as well as individual terms” (Gone et al., 2019). The importance of regaining and preserving culture and traditions will create the necessary resilience in Indigenous people because the suppression and destruction of their cultural identity and traditions were part of the historical trauma. In their article, Matheson et al. (2022) states that “resilience is fostered when the survivors of natural events are able to express and anticipate collective solidarity and cohesion, and to act cooperatively to draw on collective social support resources”. On the subject of reversing epigenetics, research indicates that “environmental enrichment could reverse the epigenetic changes that had occurred” in studies of dogs separated from their mothers (Matheson et al., 2022). This gives us hope that under the right circumstances, trauma that is encoded into our biology through epigenetics can also be healed.
Another path to healing relates to the social determinants of health (Public Health Agency of Canada, 2024). If we can ensure that all Indigenous people in Canada have the necessary socioeconomic stability, access to supportive healthcare, community, a sense of belonging, and all the other social determinants of health, then we would be further along in the path to healing. In her guest speech to our class, Tracy Underwood spoke about how the trauma took several hundred years to occur, so it could reasonably be another several hundred years for it to heal afterwards. I found this particularly important because we cannot realistically expect that after hundreds of years of trauma from colonization, cultural suppression, and genocide, that the healing will just happen. To get to that place, we first need to widely acknowledge the harms done from colonization and get to a place of actual equity where people require different levels of support to achieve equal outcomes. We are not there yet.
Conclusion
When looking at the historical traumas that have been experienced by the Indigenous peoples in Canada, I can see that over hundreds of years, white settlers have caused trauma in many forms. This trauma has etched itself into the Indigenous peoples and through epigenetics, social, and environmental transmission, it has been passed down from generation to generation. This has caused mental health crises, addiction crises, high suicidality, and cycles of trauma which will take a lot of work to undo. It is because of these crises that people then pile on judgement of Indigenous people for having mental health issues, substance use addictions, insecure housing situations, unemployment, and suicidality which further compounds upon an already painful history of trauma and oppression.
I would like to say that I have learned an incredible amount through completing this research into intergenerational trauma, especially of the Indigenous people of Canada. All of this will inform my future social work practice and allow me to continue supporting people who have experienced many different forms of trauma. After having seen how little research there has been into this subject matter, I aim to maybe have the opportunity to contribute further to the research in this area.
This exploration of intergenerational trauma reveals the undeniable truth: the consequences of historical trauma are ongoing. Those wounds continue to shape the present for many Indigenous peoples in Canada who are still negatively impacted by colonization. Breaking the cycle of trauma requires more than just awareness; it also requires action. I believe we must stand in solidarity with Indigenous communities as they reclaim their narratives, heal from the injustices of the past, and build a future rooted in justice and self-determination.
References
Baswan, M., & Yenilmez, S. (2022, July 26). The Sixties scoop. The Indigenous Foundation. Retrieved March 26, 2025, from https://www.theindigenousfoundation.org/articles/the-sixties-scoop
Buller, M., Audette, M., Robinson, Q., & Eyolfson, B. (2019, June 28). Final report. MMIWG. Retrieved March 26, 2025, from https://www.mmiwg-ffada.ca/final-report/
Elias, B., Mignone, J., Hall, M., Hong, S. P., Hart, L., & Sareen, J. (2012). Trauma and suicide behaviour histories among a Canadian Indigenous population: An empirical exploration of the potential role of Canada’s residential school system. Social Science & Medicine, 74(10), 1560–1569. https://doi.org/10.1016/j.socscimed.2012.01.026
Epigenetics, health, and disease. (2025, January 31). Genomics and Your Health. https://www.cdc.gov/genomics-and-health/epigenetics/index.html
Gone, J. P., Hartmann, W. E., Pomerville, A., Wendt, D. C., Klem, S. H., & Burrage, R. L. (2019). The impact of historical trauma on health outcomes for indigenous populations in the USA and Canada: A systematic review. American Psychologist, 74(1), 20–35. https://doi.org/10.1037/amp0000338
Hele, K. S. (2023, December 19). Colonialism in Canada. The Canadian Encyclopedia. Retrieved March 26, 2025, from https://www.thecanadianencyclopedia.ca/en/article/colonialism-in-canada
Isobel, S., McCloughen, A., Goodyear, M., & Foster, K. (2020). Intergenerational trauma and its relationship to mental health care: A Qualitative inquiry. Community Mental Health Journal, 57(4), 631–643. https://doi.org/10.1007/s10597-020-00698-1
Laricchiuta, D., Panuccio, A., Picerni, E., Biondo, D., Genovesi, B., & Petrosini, L. (2023). The body keeps the score: The neurobiological profile of traumatized adolescents. Neuroscience & Biobehavioral Reviews, 145, 105033. https://doi.org/10.1016/j.neubiorev.2023.105033
Matheson, K., Seymour, A., Landry, J., Ventura, K., Arsenault, E., & Anisman, H. (2022). Canada’s Colonial Genocide of Indigenous Peoples: A review of the psychosocial and neurobiological processes linking trauma and intergenerational outcomes. International Journal of Environmental Research and Public Health, 19(11), 6455. https://doi.org/10.3390/ijerph19116455
Orton, S. M., Millis, K., & Choate, P. (2023). Epigenetics of Trauma Transmission and Fetal Alcohol Spectrum Disorder: What does the evidence support? International Journal of Environmental Research and Public Health, 20(17), 6706. https://doi.org/10.3390/ijerph20176706
Peterson, J. (2020, November 5). The impact of intergenerational trauma [Video]. YouTube. Retrieved March 26, 2025, from https://www.youtube.com/watch?v=w_Z73kR71zw
Public Health Agency of Canada. (2024, July 18). Social determinants of health and health inequalities. Canada.ca. https://www.canada.ca/en/public-health/services/health-promotion/population-health/what-determines-health.html
Valeii, K. (2024, December 6). How does intergenerational trauma work? Verywell Health. Retrieved February 3, 2025, from https://www.verywellhealth.com/intergenerational-trauma-5191638