There was an article in Time Magazine that talked about the survivors of the holocaust and how it affected the genes of subsequent generations. A team of researchers raised male mice and separated them from their mothers from birth until they were two weeks old. The removal was at random and often. The mice were cared for normally otherwise. The trauma of sudden and unpredictable removal caused PTSD-like symptoms in the mice. Things like easily being startled and isolating themselves. 

“The investigators looked at five target genes associated with behavior—most notably, one that helps regulate the stress hormone CRF and one that regulates the neurotransmitter serotonin — and found that all of them were either overreactive or under-reactive These mice… were the equivalent of first-generation Holocaust survivors. They then fathered young and, like most males of the species, had nothing to do with their upbringing. The pups were raised by their mothers with none of the trauma and separation their fathers had suffered, and yet when they grew up, not only did they exhibit the same anxious behavior, but they also had the same signature gene changes.” (Kluger, 2010)

While studies on mice are not the same as studies on humans, often mice study results are shockingly similar behaviorally and genetically to humans. There is evidence that traumatic history in grandparents and parents can cause genetic differences that have the possibility of changing the behaviors of their children, grandchildren, and great-grandchildren.  

Those are children who have not been treated differently than their peers. Now suppose the behavior of a parent is at least partially dictated by both their genetics and the way they were raised. If that is the case, it can be easy to understand how there are multiple generations of people who had average childhoods but still grew to be adults who have symptoms of PTSD. 

Some traumas cause PTSD which happens on a much smaller scale than the holocaust. Car accidents, abuse, war, homelessness, so many other things. It has to do with how the brain processes the trauma. 

This can help us understand how some families who, by all counts desperately want to be different from their parents but end up finding themselves in similar situations to their parents—not to mention the effect of poverty and/or addiction that can further affect the way a child’s brain is forming. It will affect the way a child is raised which can then alter the way the child will behave when they are on their own. Some adults are choosing not to parent at all rather than risk their personal trauma affecting another person. 

I grew up in a place where there was a general air of expectation based on the principles: “you get what you deserve,” “pull yourself up by your bootstraps,” etc. I can clearly remember hearing people say, “I can’t understand why he would use drugs when he saw what it did to his father.” Which, I wish it was that easy. I wish that seeing how destructive a habit can be to someone would be enough to ensure someone else won’t do that thing. 

I bring this up because often as an adoptive parent, I find myself confused at my children’s behavior. I think to a degree most parents of all stripes feel that way sometimes. But I struggle to understand the why behind their behavior. 

However, getting a better understanding and acceptance of the fact that trauma changes people has helped me to not be as anxious about the why. I will probably never know why exactly my kid’s brains work the way they work. I can say with confidence that as much as they are a product of genetics, they are also a product of the environment (the ol’ nature vs. nurture argument); we are doing our best here to help them be the change for themselves and future generations.

Not all adopted children are going to have deep wells of trauma impacting their brains and bodies, but every adopted child has experienced the trauma from the loss of the bond with their birth mother—whether that bond lasted 9 months, 3 years, or a decade. They might never be able to put it into words, but many adult adoptees talk about a loss they felt and feel without having an explanation for it. It has taken me a long time to be able to stomach that fact. I hate so much that my kids hurt and there’s nothing I can do to make it stop entirely. 

I think many adoptees were done a huge disservice by their parents who were under the impression that it was best not to disclose the adoption until the child was older (or to not tell them at all if it could be helped). That’s an unfortunate piece of adoption history I wish was different. 

Look at an adoptee’s birth certificate. Post-adoption, their official birth certificate lists the adoptive parents in the lines where birth parents would have gone. I felt a strange mix of gratitude and sorrow when I saw it the first time. 

I think as adoptive parents it is our job to equip ourselves with the best knowledge we can to help our kids thrive. Even if I can do exactly nothing to change the way their brains were formed before I knew them, I can go out of my way to try and have a positive impact now that I do know them. 

I think also, as a parent who has been adopted from foster care, knowing about intergenerational trauma has helped me have more compassion overall towards birth families of past kids who have been in foster care. Yes, they were doing awful things, and yes, the kids needed to be removed for their own safety. But it is important to remember they were also once victims to a past that wasn’t even properly theirs. 


Kluger, J. (2010, September 9). Study: PTSD Survivors’ Children May Have Genetic Scars. Videos Index on Retrieved March 6, 2024, from,8599,2016824,00.html