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watch: we do a deep dive into #intergenerationaltrauma

can we inherit the trauma of our parents?

content warning: this article references childhood abuse and trauma.

since disney’s global hit encanto , tiktokers are opening up about their experiences with intergenerational trauma.

encanto follows an extraordinary family tucked away in the columbian mountains. along with a plot full of magic and dancing is the story of a family still trying to heal from a horrific tragedy decades earlier. tiktokers instantly picked up on the family dynamics and began sharing their own family experiences on the platform.

along with the psychology dynamic, another concept has also started trending in popularity: the idea that traumatic events can actually impact the way our dna is expressed in our own bodies. the theory has us wondering if it’s true — can trauma be passed through generations?

trauma’s impact goes deep

research indicates that traumatic events in our lives can have an effect on which genes our body flips the switch on.

the standard understanding of genetics is that our traits are passed down through the generations via the sperm and egg. while the genes from these cells combine to form a unique code that can then turn into a person, the genes themselves — our dna — don’t change very much through our lifetime.

of course, our body has to respond to our environment and what is needed from specific cells (i.e. a nerve cell and a muscle cell are very different, even though they carry the same genetic code.) this is where the field of epigenetics comes into play, where researchers look into how behaviours and environment can turn a gene “on” or “off,” according to the cdc.

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while environmental cues , like exposure to pollutants, viruses, bacteria and basic nutrition can play a huge role into how our genes are expressed, significant experiences — things we would classify as trauma — can also have a lasting impact.

“some of the first studies i was involved with was the impact of early childhood abuse and severe neglect on stress,” says patrick mcgowan, a professor of biological sciences at the university of toronto, and a neuroscience and epigenetics researcher. “this has repercussions for a lot of mental health outcomes, primarily involving mood disorders like depression and anxiety that can persist throughout the lifespan.”

mcgowan refers to a study that looked at the effects of early childhood neglect/abuse which showed that this lived trauma correlated with changes to markers on the dna (called methlyation) in specific parts of the adult brain. these markers don’t actually change the genetic code itself, but mcgowan and his team’s research indicated that it does change in how genes were being used by the body, impacting behaviour in adulthood.

can we inherit trauma?

for years, media’s focus on epigenetics have surrounding a few studies that might point to actually passing down these effects to future generations. a sort of inherited trauma that goes beyond concern about how our parents have raised us.

in one study, author dora costa, economist at the university of california, los angeles, and her team noted that the sons of prisoners of war held in the deplorable conditions of confederate prison camps during the u.s. civil war had a higher mortality rate than the population at large — even though they were not exposed to the camps themselves. the sons had an 11 per cent higher rate of death, even after controlling for socioeconomic and marital status.

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previous generations of sons from these families didn’t have a higher mortality rate before the war. neither did the sons of soldiers born before the fathers were imprisoned. this also seems to point to the possibility that a change in the father’s behaviour after the war could also have something to do with a higher rate of mortality.

mouse models have also indicated that conditioning a fear of a specific smells in one first generation can, under certain circumstances, result in a second generation that is sensitive to the same smell. however, researchers note that the fear doesn’t translate exactly from generation to generation: what the first generation was fearful of, the next may merely be sensitive to. mouse models also indicate that the inherited fear can be “unlearned” within a lifetime, preventing it from being passed down to the next generation.

however, many scientists warn that there isn’t enough evidence to support this game-changing theory, pointing out that the critical pathway of these chemical markers from parents’ dna to egg or sperm cells to embryo is not yet mapped out. this is especially important considering that during conception, most of these markers are wiped away, allowing the genetics of both the mother and father to combine.

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mcgowan explains that it’s difficult to precisely tease apart the genetic effects passed on from our parents versus the effects our parents will have on us once we’re born. some adoption studies in mice (where mice are immediately removed from their birth parents and placed with new parents to understand the differences between nature versus nurture) as well as in-vitro studies (where a fertilized egg is brought to term by a different mouse in an attempt to boil down the effects of genetics versus the “maternal environment” during pregnancy and after birth) have provided some evidence that genetic annotations may be passed on, but these studies all have their own potential effects on how genes are expressed. it’s not crystal clear how exactly the changes to the markers on dna translate to a functioning creature.

until this theory is better understood, disney has already released another movie reflecting complex family dynamics.

emma jones is a multimedia editor with healthing. you can reach her at emjones@postmedia.com or on twitter @jonesyjourn.
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