Examples of this include collective trauma experienced by descendants of the Atlantic slave trade; segregation and Jim Crow laws in the United States; apartheid in South Africa; the Scramble for Africa, Armenian genocide survivors, Jewish Holocaust survivors and other members of the Jewish community at the time; by the First Peoples of Canada during the Canadian Indian residential school system; and in Australia, the Stolen Generations and other hardships inflicted on Aboriginal and Torres Strait Islander peoples.
While transgenerational trauma gained attention in recent decades, the hypothesis of an epigenetic mechanism remains controversial due to a lack of rigorous experimental results on humans.
Historical trauma results in vulnerability to mental and physical health problems due to ancestral suffering which has been collected throughout generations into "legacies of disability for contemporary descendants".
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"[clarification needed] 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.
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.
[40] 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.
[8] In general, black Americans who have any mental illness are resistant to receiving treatment due to stigma, negative conceptions, and fear of discrimination.
[45] 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.
[50] In general, children of refugees exhibited higher overall levels of depression, PTSD, anxiety, attention deficiency, stress, and other psychological issues.
[55] In turn, these traumatic experiences impacted the ways that refugees raised their children since they internalized notions of being outsiders in a new country and emphasized success in the face of their many sacrifices.
European colonization has, in some instances, involved subjugation of the indigenous peoples of the Americas through violence, ethnic cleansing, forced assimilation, and acculturation.
[22] Indian reservations, and harmful policies excluding and oppressing Natives evoked similar responses to trauma as the descendants of Holocaust survivors.
Mental health workers and primary care physicians asked to take a survey entitled “Secondary Traumatic Stress Scale” reported that they had trouble sleeping, feeling emotionally numb, and having intrusive thoughts about clients.
One study found that the children of torture victims showed more symptoms of anxiety, depression, post-traumatic stress, attention deficits, and behavioral disorders than the comparison group of those who had not experienced the specific trauma.
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.
[38] The transgenerational transmission of colonial trauma is also considered a contributing factor in the high rates of mental health difficulties that Native Canadian communities experience.
[89] The experience of traumatic stress can modify cognitive, behavioral, and physiological functions, which can increase susceptibility to both mental and physical health issues.
Because the attachment relationship between parent or caregiver and child is a dominant mechanism through which transgenerational trauma is transmitted, treatment should focus on the importance familial and interpersonal patterns relative to the client, and utilize attachment-focused interventions.
[101] Some protective factors include fostering secure attachment between parent and child, as well as having access to several sources of support (i.e., family, peers, community).
[102] The model incorporates several features from existing empirically supported methods of treatment, such as trauma exposure, cognitive processing and reframing, stress management, and parent education.
[103][104][105] Specifically, analytic music therapy (AMT) was found to be effective in facilitating a degree of healing through self-exploration that mitigates the negative impact of transgenerational trauma.
[106] Outside the treatment modalities described, several tools and techniques were also found to be helpful in bringing awareness to the effects of transgenerational trauma, as well as decreasing its psychological impact.
For example, the Transgenerational Script Questionnaire (TSQ) has been used to compliment psychotherapy sessions as a means of helping to develop consciousness of both the internal and external family system.
[107][108] The TSQ targets transgenerational scripts, which are unconscious systemic patterns that persist in families and groups, and are perpetuated through emotions, beliefs, and behaviors.
[109] This process allows for clinicians to better assess the origins and maintaining factors of an individual's experience of transgenerational trauma, which ultimately contributes to a more comprehensive conceptualization of treatment.
[112] Research in rodents suggests that epigenetic changes can be observed in genes associated with the hypothalamic-pituitary-adrenal (HPA) axis, which coordinates the body's stress response system.
He says "This is a malady in modern science: the more extraordinary and sensational and apparently revolutionary the claim, the lower the bar for the evidence on which it is based, when the opposite should be true.
And I think scientists are willing participants in it in a way that I find more and more distasteful the older I get, because it does a massive disservice cumulatively to how science is understood by the general public because we have this constant hype.
"[18] The biologist Ewan Birney specifically criticized a paper which used a sample size of 32 people to back its claim that children of Holocaust survivors showed evidence of inherited stress.