The Roots of Trauma: What Shapes Our Sensitivity to Suffering

In my previous blog post about Yellowjackets, I explored what trauma can do to us—how it echoes long after the event, shaping who we become and how we cope. That post was about the impact of trauma. This one is about the vulnerability to it. Because not everyone who goes through something hard ends up carrying the same emotional scars. And not all trauma looks like panic attacks or flashbacks. Sometimes it looks like irritability, shutting down, overworking, perfectionism, or difficulty trusting others.

When people struggle in the aftermath of a traumatic experience, the question they often ask themselves—or are asked by others—is:
“What’s wrong with you?”
That question focuses on the residue—the anxiety, avoidance, emotional reactivity, or behaviors that seem “dysfunctional.” But those aren’t defects. They’re clues. They’re adaptations that once made sense in a different environment.

The more compassionate question is:
“What happened to you?”
That turns our attention to experience—the emotional bruises, the overwhelming events, the childhood adversity that overwhelmed someone’s capacity to cope or made them feel fundamentally unsafe.

But even that isn’t always the whole picture. Because two people can go through the same experience, and one may carry it like a scar while the other seems to bounce back. Which brings us to the third, often invisible layer:
“What shaped how you responded?”
This is about vulnerability—not weakness, but biology. It includes the way your body manages stress, your temperament, your inherited traits, and even how your early environment wrote itself into your nervous system through gene expression.

That’s the “informed” part of being trauma-informed: not just compassion, but clarity.
In recent years, the language of trauma has become more common—sometimes in ways that heal, and sometimes in ways that flatten the complexity. Words like “triggered” or “dysregulated” are now part of everyday conversation. And while it’s a sign of cultural progress that we’re talking about trauma at all, not all of these conversations are grounded in reliable science.

Take, for example, trigger warnings. These began as grassroots efforts among trauma survivors—especially those with PTSD—to signal potentially distressing material online. The goal was care and autonomy. But as the idea spread into classrooms and institutions, the application became broader, sometimes even performative. Research now suggests that trigger warnings don’t reliably reduce distress and may inadvertently increase anticipatory anxiety or avoidance—particularly in people with trauma histories (Bellet et al., 2018).

We now live in an age of infinite information: Google results by the billions, mental health reels on every feed, and AI-generated content available 24/7. But alongside that access has come a flood of misinformation—some of it well-intentioned, some of it careless, and some of it deeply misleading. Trauma is a complex, serious subject. And when its language is repurposed without precision—whether by influencers, institutions, or even AI—it can lead to misunderstandings that distort our view of ourselves or others. It can encourage avoidance when resilience is needed, or conflate discomfort with harm in ways that actually undermine healing.

That’s part of what motivated me to write this post (and the last one). I believe in trauma-informed care—not just as a posture of empathy, but as a commitment to discernment. If we want to meet people with compassion, we also need to meet reality with accuracy—so we can practice wisdom in our healing.

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1. Adverse Childhood Experiences: How Early Environments Shape Us

Let’s begin with the most widely understood pathway: the experiences we live through, especially in childhood.

Not all childhood stress is traumatic. But when the stress is chronic, overwhelming, and unbuffered by supportive relationships, it becomes toxic. And for many people, the roots of trauma vulnerability begin not in adulthood, but in childhood.

We often categorize Adverse Childhood Experiences (ACEs) into three broad types of negative experience:

• Abuse (emotional, physical, sexual)
• Neglect (emotional or physical unmet needs)
• Chaos (unpredictability from mental illness, substance use, incarceration, violence, or instability at home)

Originally studied in a groundbreaking collaboration between the CDC and Kaiser Permanente in the late 1990s, ACEs have since become one of the most robust predictors of lifelong mental and physical health risks. The more ACEs a person experiences, the more likely they are to struggle with depression, anxiety, PTSD, substance misuse, and chronic diseases like heart conditions or diabetes (Felitti et al., 1998); (Anda et al., 2006).

But ACEs aren’t just risk factors. They shape the developing brain. A child growing up in an abusive or chaotic environment may learn to stay hypervigilant for danger. A child neglected emotionally may develop limited capacity to regulate feelings or form safe attachments. These are not signs of damage—they are adaptations to environments where survival came before thriving.

We often ask, “Why is this adult so reactive, withdrawn, or dysregulated?”
But if we zoom out, the better question is: What kind of childhood required them to be that way to survive?

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2. Stress Biology: When Survival Mode Becomes the Default

If ACEs are the events that happen to us, the next layer is how those experiences shape the systems inside us—starting with the one that manages stress.

The hypothalamic-pituitary-adrenal (HPA) system is like our internal thermostat for stress, regulating the release of cortisol and other hormones that prepare us to fight, flee, or freeze. But in people who’ve experienced trauma—especially early, repeated trauma—this system can become dysregulated.

“When a child is overwhelmed with fear, their stress response system is activated excessively. Over time, this sensitization means they react to even minor stressors as if they’re life-threatening.”
— Dr. Bruce Perry, The Boy Who Was Raised as a Dog  (Penguin Random House)

Some trauma survivors have hyper-reactive stress systems: their bodies flood with stress hormones at the slightest trigger. Others become numb or under-responsive, barely activating even in high-threat situations. Neither is healthy. Both reflect a nervous system that has adapted to chronic threat and now struggles to return to baseline.

As Robert Sapolsky has explained (paraphrased from Why Zebras Don’t Get Ulcers), our stress-response system evolved for short bursts of physical survival—like escaping a predator. It wasn’t built to handle the chronic, low-grade stress of modern life or the internalized pain of unresolved trauma. When this system is activated constantly, it stops protecting us and starts wearing us down.

Understanding trauma through this lens invites compassion. These aren’t overreactions. They’re survival strategies encoded deep in the body (Yehuda et al., 1996); (Gunnar & Quevedo, 2007).

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3. Genetic Predispositions: The Temperament We Inherit

Of course, not everyone exposed to trauma develops long-term psychological harm. That’s where genetics enters the conversation. Some of us are simply born more sensitive—more emotionally reactive, more tuned-in to our environments, more vulnerable when things go wrong.

Imagine two kids growing up in the same noisy, unpredictable home. One of them seems to bounce from room to room, unfazed by the yelling or the slammed doors. The other startles at every loud sound, clings more tightly to routines, and takes longer to settle down after a conflict. Neither child is “wrong”—they’re just wired differently. That second child may have a biological sensitivity that makes them more affected by the same stressors their sibling seems to shrug off.

Researchers have identified inherited traits that help explain this difference. Some people are born with more reactive stress systems or more sensitive emotion-processing pathways in the brain. These traits don’t guarantee distress, but they do mean that life’s bumps and bruises may hit harder—and linger longer.

But genes don’t act alone. They don’t write a destiny—they set a stage. And what happens on that stage depends on the environment. In a calm, nurturing home, that same sensitive child might become exceptionally empathetic, creative, or attuned to others. In a chaotic one, they might grow up feeling constantly overwhelmed, like the world is always just a little too loud.

That’s the paradox of inherited sensitivity: what makes some people more vulnerable can also make them more responsive to care, safety, and connection. It’s not about hardwiring—it’s about what that wiring is exposed to (Caspi et al., 2003); (Binder et al., 2008).

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4. Epigenetics: How Trauma Echoes Across Generations

And finally, we come to the most surprising layer—the one that bridges biology and history.

Epigenetics is the study of how life experience changes how our genes are expressed—essentially turning some up and others down without changing the underlying DNA. This helps explain how trauma gets “into the body” in lasting ways.

One striking example comes from a study led by Rachel Yehuda at Mount Sinai, which looked at Holocaust survivors and their adult children. Researchers found that survivors who had been imprisoned in Auschwitz showed measurable changes in how their bodies regulated stress. More remarkably, their children—who had never experienced the Holocaust—showed similar biological patterns (Yehuda et al., 2014).

Another study, also led by Yehuda, followed women who were pregnant during the September 11 attacks in New York. Some of these women were in or near the World Trade Center at the time—a single, acute, life-threatening event. Researchers found that the babies born to mothers with PTSD had significantly altered stress regulation systems, as if their bodies had been shaped in utero by their mothers’ experience (Yehuda et al., 2005).

Why would this happen? One theory—one I find compelling—is evolutionary. If a parent’s body endures prolonged or severe stress, it may biologically “warn” the next generation: Life is going to be hard. Prepare accordingly.

In harsh environments, that kind of adaptation might be protective. But when the world the child inherits is more stable or safe, the inherited stress sensitivity can become a mismatch—making life feel harder than it is.

The good news is that these biological changes are not permanent. Research has shown that supportive caregiving in early childhood—even in high-risk families—can help normalize stress responses (Parade et al., 2018). And in adults, mindfulness, therapy, and meaningful relationships have been associated with positive changes in how our bodies regulate stress and inflammation (Roberts et al., 2015).

The body, it turns out, is always listening—not just to danger, but to healing, too.

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Conclusion: From Compassion to Discernment

When we recognize these pathways—early adverse experiences, stress biology, inherited emotional sensitivity, and intergenerational effects—we move beyond moral judgments or simplistic labels. In simpler terms: what happened to you, how your body adapted to chronic stress, what you inherited from your parents, and what you carry from generations before you. We see people not as broken, but as shaped. We begin to understand that what looks like dysfunction may actually be adaptation. That what looks like overreaction may be the imprint of a nervous system doing its best to survive.

And this is not rare. Studies suggest that nearly two-thirds of adults have experienced at least one ACE, and about one in six has experienced four or more—an important threshold, as research shows that individuals with four or more ACEs are significantly more likely to suffer from depression, anxiety, substance use disorders, and chronic physical conditions like heart disease and autoimmune disorders. Meanwhile, genetic sensitivity and inherited biological patterns don’t show up in a blood test or personality quiz—but they are just as real, shaping how many of us react to stress, to relationships, and to the pressures of modern life.

Being trauma-informed isn’t just about using the right words. It’s about using them accurately. It’s not about shielding people from all pain, but about helping them carry it with understanding and agency. And in this cultural moment—when misinformation spreads as quickly as good information—discernment is part of care.

This essay is an invitation: to go deeper than the buzzwords, and to ground our compassion in what we actually know about how trauma works. Because if trauma can shape biology, then so can safety. If adversity can echo across generations, then so can healing.

And if we’re willing to meet reality with accuracy, we can begin to practice wisdom—in how we support others, in how we listen to ourselves, and in how we shape environments that allow everyone—not just to survive—but to grow, connect, and thrive.