How trauma is passed down through generations #1
This is the first in a series of explainers about generational trauma science.
This is the first in a series of articles I am putting out to dispel myths about generational trauma.
Subscribe if you would like to learn more, and this will enable you to comment—leave your questions for me on generational effects and Ill do my best to incorporate them in to future content.
Most of us have realised by now that more than just eye colour runs in families. When it comes to trauma, there is a lot of misinformation out there. Let’s consider what trauma is; whether it is inherited; whether it alters DNA, and what all this means for our future.
What is trauma?
When we experience trauma, we have encountered an event or situation that overwhelms our capacity to cope and leaves lasting effects on how our brains and bodies respond to threats. When we feel unsafe, our bodies activate our stress-response systems (including our threat detection systems).
The more trauma we encounter, the more intense the stress-response activation becomes, and over time it can change how those systems function. This makes us more sensitive to potential threats and alters the regulation of the hormones involved in the stress response.
Through neuroplasticity, the experience of trauma can also alter neural connections and patterns of activity in the brain. It can even affect the expression of some genes. If you want a more in-depth look at what trauma is, I’ve written about it previously here.
Can trauma be inherited?
Most of us, especially those who experience anxiety or depression, understand instinctively how our body’s stress architecture changes in response to stimuli, and most people don’t have an issue in accepting this to be true.
But there is widespread confusion about how trauma is passed down through generations.
Some people reject the idea entirely, seeing it as either pseudoscience or mystical fatalism. Others embrace it uncritically, assuming ancestral pain lives in us like a ghostly apparition.
Let’s get this straight: inherited trauma is a thing! Both of those views contain part of the truth, but they both also lack the necessary nuance for us to understand the true complexity of how trauma might transmit.
Generational trauma is not magic, but I argue it is deterministic—not in the sense that we are at the whims of fate, nor can we predict outcomes for individuals with any real certainty, but in the sense that our biological systems shape our social systems, and our social systems shape our biological systems.
Bear with me.
We are all born, but none of us chose to be. We didn’t choose our biology, we didnt choose our parents, nor our relationship with them (at least as children). We didn’t choose our social conditions or the general environment around us, and neither did our parents.
But! We are not destined to suffer because they did, or another way to put this, our children are not destined to suffer because we did. I am merely saying that behaviour, stress physiology, emotional regulation and worldview emerge from an interconnected web of influences, many of which begin long before birth.
The reason for hope is actually the complexity; the effects of generational trauma (and even direct trauma) are dynamic, probabilistic, plastic and interactive. They can constrain the trajectories available to us without allowing anyone to know in advance exactly where those trajectories will lead (which is the central reason to keep trying).
These effects do shape parenting behaviour, emotional reactivity and endocrine function. In some cases, they may also involve changes in gene expression.
Is it really in your DNA?
The question everyone is obsessed with!
Discussions of gene expression often turn quickly to epigenetics, but the relationship between trauma and DNA is frequently misrepresented. First, a caveat: Epigenetic mechanisms can help regulate gene activity, although not every change in gene expression is epigenetic.
So let’s attempt a more accurate account:
Your DNA is like a musical score: almost every cell contains essentially the same DNA sequence. Gene regulation acts like the conductor, directing which parts are performed, when they are performed and how loudly. The resulting performance is gene expression.
Experience, such as trauma or adversity, can influence performance. Some genes may become upregulated, like turning a volume dial up, while others become downregulated, turning the volume down. These changes do not alter the underlying genetic code, but they can affect how cells and bodily systems respond to stress. These are direct effects, that is, if you directly experience the trauma or adversity yourself.
There is now a pretty big body of research demonstrating that some of these direct epigenetic effects can be passed down to offspring, especially in model species such as mice and fruit flies. In humans, there is not yet solid evidence that these effects are passed down. But I do think there is growing reason to suspect that some trauma-related changes can sometimes influence subsequent generations.
For this to occur though, the relevant information must be carried by sperm or ova during conception and survive the extensive epigenetic “resetting” that occurs during reproduction and early development. Even if this does happen, this germline transmission is likely to account for only a relatively small proportion of the variation in generational trauma effects.
The much larger influence is likely to come from the biological, developmental, and social conditions acting on us from conception onward (or indeed direct effects from our DNA itself, such as how we might respond to stress). These include (but are not limited to) the prenatal environment, hormonal and immune signalling, early brain and stress-system development, caregiving, family relationships, socio-economic circumstances, family and cultural attitudes towards mental health, and experiencing direct exposure to threat.
So what I’m trying to say is, if you placed all of these possible effects, biological, social, historical and cultural into a pie, and if you were somehow able to slice the “epigenetic effects” piece out of that pie, it would be a really small piece, and I myself would not be satisfied by that small slice!
Is change possible?
So as I indicated earlier, because what happens after conception is likely to matter far more than any trauma-related changes present in a parent’s sperm or ova, there is direct room for helpful intervention. This does not mean that nurture is more important than nature (because they are always interacting).
Development after conception is itself thoroughly biological, while also being shaped by relationships and social conditions.
Crucially, even if epigenetic effects turn out to be more important than we thought, they are still not necessarily permanent. Gene expression remains responsive to environmental input, and our neural and hormonal systems retain varying degrees of plasticity—throughout our entire lives.
What this really means is that trauma experienced either directly or indirectly can leave biological traces, but those traces are not our destiny.
So “cycle breaking” really becomes about support, safety and social connection because these are more within our control and can help shape these systems in new directions.
Change remains possible.
Other articles about trauma and generational trauma:
Trauma might be carried in your DNA— but it’s not that simple
After mass violence, trauma spends socially. Here are 3 ways you can help reduce it.
Visit my YouTube for more.
Subscribe to leave comments asking your questions about generational trauma (or any topic about human behaviour). Selected questions will be answered in subsequent essays, explainers and YouTube videos.
Subscribe to leave comments asking your questions about generational trauma (or any topic about human behaviour). Selected questions will be answered in subsequent essays, explainers and YouTube videos.