Epigenetics is the branch of science that looks at differences in genetic expression or phenotypic changes. When a parent experiences certain environmental stimulation, they develop a response to it. The parent then passes on their DNA proteins (which includes genetic and phenotypic data) to the offspring. When the zygote is formed, the phenotypic variations are reset. However, this process does not erase all the phenotypic data, leaving behind some expressions in the offspring. When these expressions are seen in the offspring despite the absence of the original stimulant, it is called transgenerational epigenetic inheritance.
Trauma is also believed to be inherited in a similar fashion. Transgenerational trauma has been popularly researched on holocaust survivors and prisoners of war (POW). These effects can extend to other populations that experience stress, trauma and Post Traumatic Stress Disorder (PTSD). Pregnant women in Rwanda during the Tutsi genocide in 2011 and their children were studied for depression and other relevant markers. Cortisol levels (associated with stress) were much higher in the children of women who were exposed to the genocide than those who had migrated from Rwanda. The mothers’ exposure to stress led to epigenetic changes in their offspring.
A similar pattern was noted in Congo women, who experienced prenatal stress, and their children. Stress and trauma during the prenatal stages may not be strictly causal, but they stand as a reminder of the importance of prenatal and postnatal care for mothers and their children for reducing mental vulnerability in upcoming generations.
An important approach that epigenetics brings out is a contradiction to the popular nature versus nurture debate. Reproduction involves creation and replication of cells received from the parent DNA, which is why people can easily assume children are simply a duplication of their parents for multiple traits and behaviours. However, it is not the DNA, but the proteins which make up the DNA, that is received from the parent. These proteins create DNA in an environment of interactions by neurochemicals and neurotransmitters. The production of these chemicals is regulated by the interactions they have with their environments, such as the food they eat or the emotions they feel.
Other victims of environmental and socio-cultural trauma include obesity and schizophrenia, respectively. A 2020 study concluded that obesity can have more catalyzers than just a sedentary lifestyle. Environmental exposure of previous generations can increase the likelihood of obesity in offspring generations even when those environmental stressors are no longer present. Similarly, the chances of a child developing schizophrenia are higher than average if their parent has the disorder. Genetics account for a 10% increase in risk, but social factors like adversities can increase it even further. Adversities faced by the parent can cause chemical changes that lead to epigenetic expressions in the child. These expressions or “epigenetic marks” can influence the risk of schizophrenia even in the absence of these adversities.
A facilitator to such epigenetic inheritance is the transgenerational atmosphere. Researchers explain that survivors can create an atmosphere of elaborated suffering around them. Children in such families unwittingly experience this “traumatized psychological field” – an atmosphere that is saturated with the remains of the traumatic experience of the parent. The child is unintentionally exposed to the vulnerability in this atmosphere and grows up with a sense of trauma that is never originally a part of their own life.
Dealing with transgenerational trauma can be complicated due to covert clinical presentation and a lack of sure-shot interventions. One of the methods used to combat this is the Transgenerational Trauma and Resilience Genogram (TTRG). It has a framework that focuses on the larger ecosystems – familial, cultural, and sociopolitical – around the survivor/client. Researchers have also advised using transgenerational trauma interventions for disasters survivors to enhance the care provided to them via counselling. Another intervention is the Adaption After Persecution and Trauma (ADAPT) model which works on a community level for people who experienced mass trauma, like colonization. The ADAPT model emphasizes the motto “healthier the community, healthier the individual” in putting a pause on the transmission of trauma through generations.
Transgenerational trauma has been one such space where an interdependent outlook of genes and environment has resulted in more effective assessments and treatments. Infinite interactions and individual mapping coexist in human development under epigenetic transgenerational inheritance. It has highlighted the need for ecosystemic specificity, which requires system-specific information for the same psychological problems, their presentation, prevention, and remediation in different individuals.
So far, we have been trying to single-out the source which makes an individual the way they are. Instead, it is time that we shift our focus to the interactions that influence a person’s life. Transgenerational epigenetic inheritance is built upon the interaction of genes and the environment. This new perspective can pave the way beyond the age-old nature versus nurture dualism – beyond the black and white, into a colorful spectrum of interactions that shape human lives.
Jahnvi Jose
