Transgenerational trauma


Transgenerational trauma, or intergenerational trauma is a psychological term which asserts that trauma can be transferred in between generations. After a first generation of survivors experiences trauma, they are able to transfer their trauma to their children and further generations of offspring via complex post-traumatic stress disorder mechanisms. This field of research is relatively young, but has expanded in recent years.

History

Intergenerational trauma was first recognized in the children of Holocaust survivors. In 1966, psychologists began to observe large numbers of children of Holocaust survivors seeking mental help in clinics in Canada. The grandchildren of Holocaust survivors were overrepresented by 300% among the referrals to a psychiatry clinic in comparison with their representation in the general population. Since then, transgenerational trauma has been documented in descendants of slaves, Native Americans, war survivors, refugees, survivors of interpersonal abuse, and many other groups.

Historical trauma

Instances of Transgenerational trauma where the trauma is a shared experience amongst a group of people and their role in society, are often referred to as historical trauma. In general, Historical trauma consists of three factors: the widespread nature, traumatic events resulting in a collective suffering, and the malicious intent of those inflicting the trauma. This form of trauma is specific as it affects a large population and is typically more complex than individual trauma. Historical trauma can result in a greater loss of identity and meaning, which in turn may affect generations upon generations until the trauma is ingrained into society.
Building upon the clinical observations by Selma Fraiberg, child trauma researchers such as Byron Egeland, Inge Bretherton, and Daniel Schechter have empirically identified psychological mechanisms that favor intergenerational transmission, including dissociation in the context of attachment, and "communication" of prior traumatic experience as an effect of parental efforts to maintain self-regulation in the context of post-traumatic stress disorder and related alterations in social cognitive processes.

Symptoms

Symptoms of intergenerational trauma always begins with the survivor of a trauma, which tend to manifest as symptoms of PTSD. Oftentimes trauma in the second generation is deemed as a traumatic response to parental trauma. Transmission between the parent and child can be broken down into 5 measures: communication, conflict, family cohesion, parental warmth, and parental involvement. High levels of maternal stress were directly correlated with weak family functioning and indirectly correlated with deviant behavior among children. Common symptoms in children consisted of depression, antisocial behavior, delinquency, and disruptive behavior in school. Some children experienced direct transmission in which their trauma stemmed from the interactions and relationships with their parents, while others experienced indirect transmission in which their trauma was mainly rooted in guilt. Those who were affected through direct transmission were more likely to lash out through their actions, while those who were affected through indirect transmission were more likely to suffer from depression, anxiety, and guilt.
Symptoms also differed based on ethnicity and type of original trauma. Enslavement, genocide, domestic violence, sexual abuse, and extreme poverty are all common sources of trauma that lead to intergenerational trauma. A lack of therapy also worsens symptoms and can lead to transmission. For instance, survivors of child sexual abuse may negatively influence future generations due to their past unresolved trauma. This can lead to increased feelings of mistrust, isolation, and loneliness. Descendants of slaves when faced with racism-motivated violence, microaggressions, or outward racism, react as if they were faced with the original trauma that was generationally transmitted to them. There are a variety of stressors in one's life that led to this PTSD-like reaction such as varying racist experiences, daily stressors, major race-related life events, or collective racism or traumas. This also presents itself in parenting styles. Parents who not only receive the trauma genetically but also experience stressors frequently may create a home environment that deflects the stress they experience, adding on to the inherent stress of the child. Goodman and West-Olatunji proposed potential transgenerational trauma in the aftermath of natural disasters. In a post-Hurricane Katrina New Orleans, residents have seen a dramatic increase in interpersonal violence with higher mortality rates. This phenomenon has been also been reported in the descendants of Indigenous students at residential schools, who were removed from their parents and extended family and lacked models for parenting as a result. Being punished for speaking their native language and forbidden from practicing traditional rituals had a traumatic effect on many students, and child abuse was rampant in the schools as well.
Symptoms of transgenerational trauma have in recent years been identified among Black Americans, in relation to the effects of slavery and racial discrimination. This passing of trauma can be rooted from the family unit itself, or found in society via current discrimination and oppression. The traumatic event does not need to be individually experienced by all members of a family; the lasting effects can still remain and impact descendants from external factors. For example, Black children's internalization of others' reactions to their skin color manifests as a form of lasting trauma originally experienced by their ancestors. This reaction to Black skin stems from similar attitudes that led to the traumatizing conditions and enslavement of slaves. Black children and youth are more susceptible to racial trauma because they have not yet acquired the knowledge to have a full understanding of racism and its effects. However, these traumatizing behaviors experienced at such a young age are a reflection of a child's parenting. A White child may learn racist behaviors from their environment, but on the same token a Black child can learn to assert their blackness and how to respond to racist remarks and actions from their parents. Traces of trauma have an impact on Black and other minority children's success in an educational context. Transgenerational trauma has also been heavily recorded in refugees and their children, which can last through several generations. Such traumas can stem from violence, political persecution, familial instability, as well as the hardships of migration.

Affected groups

Descendants of slaves

In recent years, symptoms of transgenerational trauma has been identified among Black Americans, in relation to the effects of slavery and racial discrimination. This passing of trauma can be rooted from the family unit itself, or found in society via current discrimination and oppression. The traumatic event does not need to be individually experienced by all members of a family; the lasting effects can still remain and impact descendants from external factors. For example, Black children's internalization of others' reactions to their skin color manifests as a form of lasting trauma originally experienced by their ancestors. This reaction to Black skin stems from similar attitudes that led to the traumatizing conditions and enslavement of slaves. Black children and youth are more susceptible to racial trauma because they have not yet acquired the knowledge to have a full understanding of racism and its effects. Traces of trauma have an impact on Black and other minority children's success in an educational context. Trangenerational trauma has also been heavily recorded in refugees and their children, which can last through several generations. Such traumas can stem from violence, political persecution, familial instability, as well as the hardships of migration.
In general, Black Americans who suffer from any mental illness are resistant to receiving treatment due to stigma, negative conceptions, and fear of discrimination. This reduces the number of those affected to seek help. Lack of treatment causes the symptoms to compound leading to further internalization of distress and a worsening of mental health in the individual. Those affected by race-based trauma oftentimes do not seek treatment not only because of stigma but because of fear that the medical professional will not understand their perspective of a disenfranchised minority. Furthermore, the existing stigma of mental health has led to a lack of research and consequently treatment. However, lack of treatment can also be attributed to the misdiagnosis of symptoms. Signs of trauma exhibited in Black children are often labeled as behavioral or educational disabilities, allowing the trauma to go untreated. While trauma symptoms often manifest as other mental illnesses such as depression and anxiety, the larger diagnosis often goes untreated.

Native Americans

Intergenerational Trauma has also been documented in Native American families. While it is difficult to maintain large generalizations about an ethnic group that is non-homogeneous, in comparison to other minority groups in the US, Native American are more likely to suffer from mental illness and have a suicide rate higher than the national average. However, it is difficult for researchers to understand to what extent these statistics are due to intergenerational trauma. For example, Native Americans today still face discrimination and persecution by the US government and many symptoms that stem from events could easily be misdiagnosed as intergenerational trauma. Still, some research has shown that the worst cases of intergenerational trauma were documented in Native Americans and persisted through 6 generations.

Indigenous Canadians

The fact that Canadian Indigenous groups experience mental illness, suicide and substance use problems more than non-Indigenous populations has been cited as an example of intergenerational trauma. The Truth and Reconciliation Commission describes how Indigenous individuals experienced high rates of physical and sexual abuse in the residential school system, and that the children of Indigenous individuals who never directly experienced the residential school system themselves may still exhibit trauma sensitivity that is disproportionate to their lived experiences thus far. This is considered evidence that the negative impact of Canadian colonization on Indigenous wellbeing has been transmitted down through generations of Indigenous families.

Koreans

Han is a concept of an emotion, variously described as some form of grief or resentment, among others, that is said to be an essential element of Korean identity by some, and a modern post-colonial identity by others.
Jon Huer describes han as a generational feeling of "having been 'wronged' by a superior agent", such as fate or the government. According to John M. Glionna, han is "intensely personal, yet carried around collectively, a national torch, a badge of suffering tempered by a sense of resiliency". According to Joshua D. Pilzer, the idea of han as a national characteristic is recent and arises from Koreans' "modern search for national essences in the wake of colonialism, and in the midst of authoritarian capitalist development and national division".
Michael D. Shin argues that the central aspect of han is loss of identity, and defines han as "the complex of emotions that result from the traumatic loss of collective identity". Han is most commonly associated with divided families: families who were separated during the Korean War. According to Shin, all Koreans may experience han, or a "constant feeling of being less than whole", because of not having a collective identity as a result of the continued division of Korea. Furthermore, new generations of Koreans seemingly inherit it because of growing up in a divided country.

Refugees

One group of people that is often more likely to experience transgenerational trauma is refugees. While all refugees experience some sort of trauma, war related trauma has been documented to have longer lasting effects mental health and span through more generations. Children are especially prone to the trauma of resettling as their childhood has been disrupted by a migration to a new country. They also often face the difficulty of learning a new language, adapting to a new environment, and navigating the social system of school in their host country. Furthermore, most host countries, do not provide an adequate mental healthcare systems to refugees which can worsen symptoms and lead to transmission of trauma. In general, children of refugees overall had higher levels of depression, PTSD, anxiety, attention deficiency, stress, and other psychological issues. Oftentimes, these symptoms manifest as teen delinquency and violent behavior.

Cambodian

Since 1975, the US has accepted many refugees from Vietnam, Cambodia, Thailand, and Laos. While majority of these groups were fleeing war and poverty, Cambodian refugees were also fleeing a genocide from the Khmer Rouge. The atrocities of violence, starvation and torture were common themes experienced by these refugees. Compared to the national rate of PTSD, Cambodian refugees were found to have a significantly higher rate of PTSD. While over parenting can sometimes be seen as a symptom of PTSD, this was not widely expressed among Cambodian Americans. Instead, many Cambodian refugee families refused to talk about their trauma creating an isolating environment for the child. This lead to a transmission of trauma and through the continuing pattern of silence and refusal to acknowledge an issue or seek treatment. Recent evidence also suggests that the intergenerational trauma can stem from a generational, cultural, and language divide amongst children and their parents. Parental expectations of the hierarchical structure of the family, familial obligations, and a language barrier were found to be common themes of conflict. Studies also showed that when both parental figures had PTSD, the child was more likely to have higher rates of PTSD. There has also been data showing that the children of survivors from regions with higher rates of violence and mortality displayed stronger overall symptoms. Role reversal parenting as a form of therapy has show to have positive outcomes amongst Cambodian Americans and have helped to mend broken relationships between parent and child with a much more significant effect on mothers and daughters. In this type of therapy, the parent looks to the child for emotional support which may lower PTSD in the parent, and decrease a sense of isolation and abandonment for the child.

Survivors of childhood abuse

Transmission

Epigenetic transmission

Previous research assumed that trauma was only transmitted by the parents' child-rearing behavior. However, it may also be epigenetically transferred. Epigenetics studies how gene expression and cellular activity is influenced by external factors such as environment. A vastly researched event of epigenetics modifying genes within generations is the Dutch Hunger Winter Famine. Those directly experiencing the famine suppressed specific genes and expressed other ones that aided in survival. When the survivors had offspring, their children also had the same genes suppressed and/or expressed. Therefore, one way trauma can be transferred is through epigenetics. Furthermore, when a child is raised in the same environment as their ancestors, it can trigger the reformation of a gene in each generation; this is the most indirect form of epigenetic imprinting.
The epigenome may also be passed through the gametes. For this to occur, the epigenome must be present in the germline. The epigenome is also extensively reprogrammed during germ cell differentiation and after fertilization to create totipotent cells, erasing many changes that occur during an individual's lifetime. Therefore, the best candidates for heritable epigenetic marks are located at repeat/transposable sequences or regulatory elements that are resistant to reprogramming. Since epigenetic mechanisms can be affected by the environment, it is difficult to determine the extent to which the environment and direct inheritance influence offsprings' epigenome. Therefore, the most compelling studies are in lab settings with controlled environments.
Non-coding RNA is currently one of the most investigated epigenetic mechanisms in the study of transgenerational trauma. Small ncRNAs guide histone methylation and post-transcriptionally regulate mRNA. In C. elegans, starvation-induced stress triggered the expression of small RNAs that cause gene silencing and persist for several generations. These generational effects have been correlated with behavioral phenotypes in some studies. When microRNA from the sperm of these C. elegans was injected into fertilized oocytes, the offspring exhibited similar phenotypes. Although the mechanism of this transmission is complex, one hypothesis is that piwi-interacting RNA and exogenous RNAi are involved in a pathway with secondary small RNAs and chromatin regulatory complexes that results in stable transgenerational inheritance.
DNA methylation is another mechanism studied for transgenerational epigenetic inheritance. 5-methylcytosine is the form of methylated DNA linked to gene repression in mammals, and N6-Methyladenosineis linked to promotion of gene activity. Various empirical studies have shown that trauma alters methylation patterns in the offspring of survivors, predominantly at the glucocorticoid receptor gene. For DNA methylation to be inherited, it has to be stable enough to undergo mitosis and meiosis, and it must escape the aforementioned epigenetic reprogramming. 5mc at repeat sequences and rare regulatory elements are resistant to reprogramming. However, it has been hard to find methylated regions that are stable over multiple generations, and there have been a lot of discrepancies across studies. These discrepancies may be due to method of methylation analysis used or due to variations in the epigenome between individuals.
Recent evidence suggests that histone modifications may also be inherited across generations. Histones tend to be preserved at housekeeping sites and developmentally regulated genes in sperm and are preserved everywhere in oocytes.
Although it isn't confirmed, if changes in the histone modification machinery were to cause phenotypic changes, a second epigenetic mechanism may be involved.

Transmission during pregnancy

Another major way that stress can be transmitted across generations biologically is through the uterine environment. The gestational stage is a developmentally sensitive stage in an individual's lifespan. Exposure to harmful stimuli during this stage can have long-lasting, detrimental effects. The uterine environment with its unique blend of the mother's cellular secretions and proteins is a major source of stimuli. Empirical evidence has shown that trauma experienced by a mother during pregnancy can affect offspring's physiology and psychology. One possible method of transmission is through transport vesicles transferring amino acids and microRNA from the uterine fluid to the fetus. These molecules may then alter gene expression in a way that affects the developmental trajectory of the fetus. Most biological research on transgenerational trauma has focused on the hypothalamic-pituitary-adrenal axis, which is the center of the body's stress response system. One way the HPA axis responds to stress is by triggering the production of glucocorticoids, primarily cortisol. Cortisol triggers “fight-or-flight” physiological symptoms like increased blood pressure and heart rate. In animal models, maternal stress and trauma during pregnancy has been shown to reduce the expression of placental enzyme 11B-hydroxysteroid dehydrogenase type 2, which converts the mother's cortisol to inactive cortisone. This leads to increased fetal exposure to the mother's glucocorticoids, which affects the development of glucocorticoid-sensitive systems like the HPA axis. In some studies, abnormal cortisol levels compared to controls and alterations in DNA methylation were observed in infants of mothers who endured trauma while pregnant, particularly in the NR3C1 glucocorticoid receptor gene.

Psychological and social aspects

There are many current transgenerational studies that have been done on adults that have experienced natural disasters or adversities. One study found that the children of torture victims showed more symptoms of anxiety, depression, post‐traumatic stress, attention deficits and behavioral disorders compared with the comparison group of those who had not experienced the specific trauma. A qualitative study was done on the Brazilian children of Holocaust survivors. This study was able to propose not only a supported model of the transgenerational transmission of traumatic experiences, but one also of resilience patterns that can be transmitted in between generations and developed within generations. Researchers Cowan, Callaghan, & Richardson studied the impact of early-life adversities on individuals and their descendants. Their research was also consistent with the transmission theory, in which their findings revealed that the stress phenotype that was expressed in individuals who experienced the adversity was also observed in children and even grandchildren.
The famous study of Harlow's monkeys also revealed that the adversity of a maternal variable which would create stress in the individual was also witnessed in their offspring although not having experienced the adversity. One last study displayed that if children were exposed to high postnatal maternal licking/grooming and arched-back nursing then they were likely to do the same to their offspring. Vice versa, if children experienced low LG-ABN mothers, then they were likely to provide the same to their offspring. Consequently, this causes a decrease in serotonin and expression, and an increase in methylation. Ultimately, a more stressed pup is created, causing this phenotype to be passed on through experience and genes.
Theses studies allude to the fact that oftentimes adversity, especially early on and for longer periods of time, can impact development in individuals and their offspring.
The oppression that blacks experienced through slavery and racism has a psychological impact on how they view achievement. In terms of the social aspects of this, seem to make it difficult for blacks to surpass a certain SES threshold, to escape a certain neighborhood, to move beyond a certain lifestyle or status.
For Native Americans, past government policy and internal displacementis theorized to have an effect generations later. The social enforcement of their ostracization causes them to be generally removed from society, to be powerless and uninvited in government, and to be left to fend for themselves. The transgenerational transmission of colonial trauma is also considered a contributing factor in the high rates of mental health difficulties Canadian Indigenous communities experience. Displacement and maltreatment during colonization had led to negative effects in the children of Indigenous peoples who survived such experiences. This is passed down generationally via ongoing social marginalization and lateral violence. The loss of Indigenous cultures and resulting lack of community cohesion poses a further challenge for Indigenous groups in resolving transgenerational trauma.

Treatment

Like all other mental disorders, the key to preventing transgenerational trauma is to recognize the issue and to intervene before transmission occurs. Because intergenerational trauma often stems from other issues, it is often unrecognized or misdiagnosed by clinicians. Moreover, there is a lack of trauma therapy specialists in the US which further affects treatment. A lack of treatment has many consequences such as health, behavioral, and social issues that can persist throughout the child's life.
In more complex intergenerational trauma diagnoses, the Transgenerational Trauma and Resilience Genogram can be helpful to clinicians to fully grasp the situation. The TTRG maps out the family unit, marking those who have experienced trauma and their experience, as well as relationships between individuals, and patterns of functioning.