History vs. Your Story
DNA History Month
In just a couple weeks, we will usher in America’s celebration of heritage and history months. January doesn’t have one designated, but the buzz around personal DNA kits that arises each holiday season suggests that many people are focused on their personal genetic history. It is in these earliest weeks of the new year that many people take their first plunge into genetic genealogy. They learn about health risks, ancestry, and “lifestyle and environment” factors. They also begin thinking deeper about the role of the past and future in their present-day strategies and choices.
One thing that I’ve been asked about lately as my friends and family have dug into their own DNA pasts is heritability. Are we really just a product of our biological mom and dad’s DNA? Can we parse our genomes into halves that replicate the sum of who they’ve become? How tethered are we to our ancestors’ DNA?
Well, it’s true that our cells are “diploid,” a.k.a. made up of a copy of each of our bio-parents’ 23 chromosomes. But every time our bodies make sex cells, they shuffle those 46 chromosomes into one copy to be passed down via our egg or sperm. So we are not exact copies of them nor are we passing down to our children exact copies of ourselves. On top of this, there are many copying errors as DNA is replicated and passed on. We are never the same as another human being. Even identical twins are not 100% genetically the same.
The Good, The Bad, and The Questionable
This scientific explanation probably leaves you wanting. I get it. What people really want to know is whether we are going to end up like our parents. The answer to that is more complicated.
Genes don’t program our behavior. They interact with environmental factors like the quality of our food, air, water, and sleep. They are shaped by how we feel, how safe we are, and how we are treated by others. So we have the potential to live out very different lives than our forebears.
At the same time, if you grew up with your parents as major influences on you, especially if they were your primary caregivers when you were little, then the environment you grew up in was heavily influenced by them–their values, habits, behaviors, interactions, etc. So many external drivers of your internal growth were indeed conditioned by them. From this socio-historical and cultural input, things about them were transmitted to you and emblazoned in who you have become.
Inherited Trauma
Looking at it from a genetic standpoint, there is bad news and good news about our DNA’s past and future. The bad news is that trauma does get under our skin and can negatively impact our biological processes via the epigenome. We can pass on harmful changes to our genome and give our offspring poorer life chances.
The good news is that when we challenge the harmful behaviors and replace them with healthful ones, we can effect positive changes to that epigenome. We can turn the tide and pass on an even healthier legacy to our future generations.
Many of us are beginning to see that it is okay to reject things that don’t serve us. It is worthy to continue to love those emotional “influencers” in our lives and yet stake out a new path forward. This is way harder than words on a page convey, but for most of us this is our reality. We have to find ways to live with trauma, accept those who were a part of it while rejecting their own strategies and choices, and do better for the future generations who deserve only the best.