Siblings cope with trauma differently. Here's why.

Family Dynamics & Boundaries • July 7, 2019

Maya Still Can’t Explain It to Her Sister

Maya is forty-one. She runs a design firm, has two kids, and a therapist she’s seen every other week for three years. She’s done the work. She knows the language — attachment, nervous system dysregulation, relational trauma. She can articulate, with impressive precision, how growing up with a volatile, emotionally unpredictable father shaped her anxiety, her perfectionism, and the way she flinches when someone raises their voice.

Her sister, Diane, remembers it differently. Their dad was “just stressed.” He worked hard. He had a temper, sure, but he loved them. Diane isn’t in therapy. She doesn’t feel like she needs it. She gets a little impatient when Maya brings it up at family dinners — a small tightening around the eyes, a subject change that arrives too quickly.

Maya leaves those dinners feeling the particular loneliness of someone whose truth has been quietly dismissed by the person who was supposed to share it. She wonders, sometimes, if she’s imagining things. If she’s been too sensitive all along.

She isn’t. But Diane isn’t lying, either.

This is what makes sibling trauma dynamics so complicated, and so painful: two people, same house, same parents — and genuinely different experiences of the same childhood. Not because one of them is wrong. Because the science of human development tells us that’s exactly what we should expect.

What Is Relational Trauma?

Before we go further, it’s worth naming what we’re actually talking about. Because “trauma” is a word that gets stretched in a lot of directions, and some people — maybe you, maybe your sibling — resist it entirely because it sounds too dramatic for what you experienced.

Relational trauma doesn’t require abuse in the conventional sense. A parent who was emotionally absent, chronically anxious, unpredictable, or critical can create the conditions for it. So can a parent who was loving in some ways but utterly unavailable in others — the dad who showed up to soccer games but never once asked how you were feeling. The mom who gave hugs but exploded without warning.

And here’s what’s crucial: two children can be raised by those same parents and develop very different internal landscapes because of it. Not because one is more sensitive, or more dramatic, or making it up. Because of biology, timing, role, and the particular relational dance each child formed with each caregiver.

If you’ve ever tried to explain your childhood emotional experience to a sibling who responded with blank incomprehension, this is why.

The Science of Why Siblings Diverge

The research on this is rich, and it points in a consistent direction: growing up in the same family does not mean growing up in the same environment. Not really.

In 1987, behavioral geneticist Robert Plomin, PhD, and his colleague Denise Daniels published a now-landmark paper that asked a deceptively simple question: if family environment shapes who we become, why are children raised in the same family so different from each other? Their answer introduced the concept of the nonshared environment — the idea that what matters most developmentally isn’t the family environment both siblings share, but the unique micro-environments each child experiences. How parents treat each sibling differently. Which child becomes the confidant and which becomes the scapegoat. Who was born during the financially stable years and who arrived during the divorce.

Plomin’s later work, including a 2024 paper in JCPP Advances, continued to affirm that nonshared environmental effects — the experiences that distinguish one sibling’s development from another’s — account for a substantial portion of why children in the same household turn out so different. The salient environment, he noted, is often “unsystematic, idiosyncratic, or serendipitous.” It includes accidents. Illnesses. The particular way a parent looked at you on one pivotal afternoon. Chance matters. Timing matters. Birth position matters.

Then there’s the work of developmental psychologist Jay Belsky, PhD, professor of human ecology at the University of California, Davis, and one of the world’s leading researchers on child development and environmental sensitivity. Belsky’s differential susceptibility hypothesis — developed across decades of research, including a widely cited 2007 paper in Current Directions in Psychological Science — proposes that children differ innately in their sensitivity to their environment, and they differ in both directions. Some children are, by biological and temperamental disposition, more affected by negative environments — and also more capable of benefiting from positive ones. These aren’t simply “vulnerable” children. They’re highly plastic children: more responsive to everything, for better and for worse.

This is why the sibling who seemed “fine” growing up may genuinely have been less affected. It doesn’t mean the family was fine. It means that child’s nervous system processed the same input differently — absorbed less, was buffered more, or happened to form a more secure attachment with one parent while you formed an anxious or avoidant one with another.

These findings matter because they dissolve one of the most corrosive beliefs in sibling trauma dynamics: the idea that if one sibling is doing better, the other must be exaggerating. The research says otherwise. Same inputs. Different outputs. Always.

How Differential Responses Show Up in Driven Women

In my work with clients, I see a particular pattern that emerges for the sibling who was more sensitive — the one who absorbed the family’s dysfunction more deeply and carried it further into adulthood.

Often, she’s the driven one. The one who got good grades, went to a competitive college, built a career that’s impressive from the outside. She’s the one who sits across from me and says, with genuine bewilderment: “My sibling had the same childhood and they’re fine. I’m the messed-up one. What’s wrong with me?”

Nothing is wrong with you. But let’s look at what that “drive” might actually be.

For many of the women I work with, the relentless ambition that defines their professional lives is, in part, a coping strategy that formed in childhood. When home feels unpredictable or unsafe, achievement becomes armor. A report card full of A’s is something you can control. A credential, a promotion, a title — these are measurable, legible forms of worth in a world where your emotional worth felt unreliable. The driven woman who carries childhood relational trauma often isn’t running toward success. She’s running away from the feeling of being not enough.

Her sibling — the one who “seems fine” — may have found a different strategy. Emotional detachment. Minimization. A thick narrative about how it “wasn’t that bad.” That’s not health. That’s a different kind of coping. One that may surface differently — in their relationships, their parenting, their capacity for intimacy — even if it doesn’t show up as anxiety or a therapist’s waiting room.

Neither sibling is broken. Both are doing exactly what their nervous systems learned to do in order to survive the same home.

What I consistently see is this: the more sensitive sibling tends to feel most alone not during the childhood itself, but in adulthood — when she tries to talk about what happened and discovers that the person who was there can’t, or won’t, witness it with her.

The Role of Attachment — and How It Differs Between Siblings

One of the most important factors in sibling divergence is often the least visible: the particular attachment pattern each child formed with each parent.

Attachment isn’t just about whether your parents loved you. It’s about the specific, moment-to-moment dance between a child and a caregiver — the degree to which the caregiver was attuned, consistent, available, and responsive to that particular child’s particular needs. And because siblings are different people with different temperaments and different needs, the same parent can offer meaningfully different relational experiences to each child.

A mother who was capable of warmth and attunement but became overwhelmed by intense emotional expression might have provided relatively secure attachment to a more easygoing firstborn — and a much more anxious or disorganized attachment to a more sensitive, emotionally expressive second child. The parent didn’t change. The relational dynamic did.

Birth order shapes this, too. The eldest child often receives undivided parental attention in early development, and may also be assigned roles — the responsible one, the parentified one, the caretaker — that come with their own particular psychological cost. The youngest may have been sheltered, or may have arrived when the family system was already under strain. The middle child is, famously, navigating a space that belongs to no one. Each position in the sibling hierarchy creates a distinct relational experience, even with identical parents.

Gender adds another dimension. In many family systems — particularly those shaped by intergenerational trauma or cultural conditioning — girls and boys are treated differently, assigned different roles, held to different standards, and protected (or not protected) from different forms of harm. The daughter may have been the emotional caretaker. The son may have been exempt from emotional labor entirely. These aren’t small differences. They shape the nervous system, the internal working models children develop for what relationships feel like, and what they expect from themselves and others for decades to come.

When you try to talk to a sibling about your shared childhood and they look at you like you’re speaking a foreign language, it’s possible — likely, even — that they genuinely lived a different emotional reality. Same address. Different family.

The Both/And Reframe

This is where I want to offer you something that might feel uncomfortable at first: your sibling’s different experience doesn’t invalidate yours. And your pain doesn’t mean your sibling is wrong, or lying, or in denial.

Both things can be true.

This is the Both/And of sibling trauma: your experience was real, and it was damaging, and your sibling’s experience was genuinely different, and neither of you has the complete picture of your family of origin. Families are complex systems in which each member occupies a unique node. You don’t have access to what it felt like to be your sibling, just as they don’t have access to what it felt like to be you.

What this means in practice — and I say this gently, because it’s hard — is that pushing your sibling to validate your experience may never yield what you’re actually looking for. And waiting for them to “get it” before you allow yourself to heal is giving them a power they may never be equipped to exercise.

This came up viscerally with one of my clients, Elena. She’s a physician in her late thirties, the second of three children. Her older brother is warm but avoidant — the topic of their childhood is, as she puts it, “completely off the table.” Her younger sister has been in and out of crisis for years. Elena sits in the middle: aware, grieving, and desperate for one of them to say, “Yes. I see it too. It was real.”

What Elena is grieving, at its core, isn’t just what happened in her childhood home. She’s grieving the sibling witness she never had — the experience of being seen in her pain by someone who was there. That grief is legitimate. It deserves space. And it’s separate from the work of healing, which doesn’t require her brother’s confirmation to begin.

Both/And also means: you can love your sibling and deeply disagree with how they’ve made sense of your shared history. You can have compassion for their coping strategies and maintain your own truth. You can wish things were different between you and stop waiting for their permission to grieve what happened.

If you’re not sure where your relational patterns began, taking the quiz can be a clarifying first step — it helps identify which childhood wounds are still running the show beneath the surface.

The Hidden Cost of Comparing Your Pain

There’s a particular trap that the more-aware sibling often falls into: the comparison spiral. It usually sounds like one of these:

“My sibling turned out fine, so I must be too sensitive.”
“My sibling had it harder than I did — I don’t have the right to be this affected.”
“If I’m the only one struggling, maybe the problem is me.”

Every version of this thinking has the same effect: it turns the lens of scrutiny away from the family system and onto you, specifically. It locates the problem in your nervous system, your sensitivity, your “drama” — rather than in the relational patterns that shaped all of you.

Comparison also tends to flatten the complexity of what actually happened. Complex trauma isn’t a single wound that all siblings either received or didn’t. It’s a texture — an accumulation of thousands of small relational moments that registered differently in each child’s body. The fact that your sibling doesn’t carry it the way you do isn’t evidence that nothing happened. It’s evidence that the human nervous system is a remarkably individualized instrument.

And there’s a quieter cost, too: when you minimize your own experience in service of “not making it a big deal,” you cut yourself off from the compassion you need to heal. You can’t metabolize pain you’ve decided you’re not allowed to have.

What I consistently see in my work is that the comparison spiral doesn’t bring you closer to peace. It keeps you stuck in a loop where your healing depends on a verdict — from your sibling, from your family, from someone who was there — that may never come. Healing doesn’t require a verdict. It requires your own clear-eyed acknowledgment that what happened to you was real, it mattered, and you’re allowed to tend to it.

The Systemic Lens

When we look at sibling trauma differences through a systemic lens — that is, through the framework of the family as an interlocking emotional system — something important comes into focus: siblings don’t just have different experiences of the same parents. They’re assigned different roles within the family system itself, and those roles shape their psychology in profound ways.

Psychiatrist Murray Bowen, MD, whose family systems theory transformed the field of family therapy in the latter half of the twentieth century, gave us language for understanding this. Bowen observed that under chronic family stress, anxiety doesn’t stay contained within one relationship — it moves. It triangulates. A third person gets drawn in to stabilize a struggling dyad. In many families, that person is a child.

One child may become the identified patient — the one who acts out, breaks down, or struggles visibly, and in doing so, becomes the family’s focal point for anxiety. This child often presents as the most “troubled” adult. But the role didn’t originate in their psychology. It was assigned by the system.

Another sibling may be cast as the golden child — the one whose apparent success soothes the family’s collective anxiety about its own worth and functioning. This sibling may genuinely believe the family was fine, because the family worked hard to treat them as though it were.

A third may have learned early to disappear — to be so undemanding, so low-maintenance, that they avoided both the designation of “problem” and the burden of “hope.” Their coping strategy was invisibility. They’re not less affected. They’re differently protected.

These systemic roles matter because they determine, in large part, what each sibling gets to know about their family. The identified patient often holds the family’s emotional truth — the anxiety, the grief, the dysfunction — precisely because no one else was willing to carry it. The golden child is frequently shielded from it. The parentified child has more of it than any child should.

When adult siblings come together and try to make sense of their shared history, they’re often speaking from these roles rather than from a shared reality. And those roles — however unconsciously adopted — are tenacious. They shape what each sibling is able to see, to say, and to tolerate hearing.

The systemic lens also illuminates intergenerational patterns: the ways that anxiety, dysfunction, and coping strategies pass from one generation to the next, landing differently in different children based on timing, temperament, and the emotional climate of the family at each child’s birth. Your grandmother’s unprocessed grief became your mother’s anxiety became the unpredictability you and your siblings navigated differently. None of it was random. And none of it was your fault.

Understanding the family as a system doesn’t excuse harmful behavior. It doesn’t ask you to forgive what hurt you or to minimize the impact. It offers a wider frame — one that makes your experience intelligible, not just as a personal wound, but as part of a larger, longer story that you didn’t write and didn’t choose.

There is one particular dynamic worth naming directly here: the emergence of the family hero role — and why, in many families, it falls disproportionately on driven daughters.

In families where dysfunction or chaos is present, one child often compensates by becoming conspicuously competent. She excels at school. She doesn’t make demands. She reads the emotional temperature of every room with eerie accuracy and adjusts accordingly. She is the one the family can be proud of — the proof, to the outside world and sometimes to themselves, that things aren’t so bad. She is the family hero: the child who performs wellness so convincingly that everyone, including herself, can almost believe it.

This role tends to fall on daughters for reasons that are neither accidental nor universal, but are well-documented: in families shaped by traditional gender expectations or intergenerational cultural conditioning, girls are more likely to be socialized into emotional caretaking, self-effacement, and achievement as a form of relational currency. The good daughter who keeps her room clean, keeps her grades high, and keeps her pain to herself. The one who is least likely to be seen as “the problem.” The one who becomes, paradoxically, the most invisible carrier of the family’s unacknowledged wound.

Racial and cultural dynamics layer another dimension onto this. In families navigating systemic racism, immigration stress, or strong cultural frameworks around honor, silence, and self-sufficiency, the pressure to succeed despite — and to do so without complaint — can be particularly acute. The driven daughter in these families may have been doing double labor her entire life: performing competence for the outside world while managing the emotional consequences of a family system that had no room for her pain. Her siblings may have coped differently, or may have been exempt from these expectations by gender, birth order, or temperament. But she’s the one who arrives in adulthood holding the most, and the least permission to say so.

How to Move Forward When Your Siblings See It Differently

This is, for many women I work with, the most practically painful dimension of sibling trauma: not the wound itself, but the loneliness of having it when no one who was there will share it with you.

A few things I want you to hold:

You don’t need your sibling’s agreement to begin healing. Validation from someone who was present for the harm is deeply meaningful, and its absence is a real loss. But it is not a prerequisite. Your nervous system doesn’t require a consensus vote. It requires your own honest witnessing — and the support of someone trained to help you do that work safely.

Grieve the sibling relationship you wanted. If your sibling isn’t able to be the witness you need, that’s worth grieving directly. Not as a detour from healing — as part of it. The longing for a sibling who “gets it” is a longing for the kind of intimate, mutual knowing that family should have provided and, for you, didn’t. That’s a real loss. It deserves acknowledgment, not minimization.

Lower the stakes of the conversations you’re trying to have. You may be approaching your sibling looking for something that feels like confession or corroboration — some acknowledgment that transforms your shared history. What you might find more possible is simply being curious about their experience, without requiring it to align with yours. Their story can be different. It doesn’t have to be an attack on yours.

Consider that your sibling may not be ready. Healing moves at different speeds. Some people won’t begin doing the work of examining their family of origin until their forties, fifties, or later — sometimes triggered by becoming a parent themselves, sometimes by loss, sometimes by a crisis that makes the old coping strategies impossible to maintain. Your sibling’s current resistance to your narrative doesn’t mean they’ll never arrive at their own version of truth. It means they’re not there yet.

Protect your healing from the comparison trap. Your path forward doesn’t run through your sibling’s validation. It runs through your own clarity — about what happened, what it cost you, and what you want your life to look and feel like now. Trauma-informed therapy provides a space to do that kind of excavation safely, with a guide who won’t ask you to minimize what you know to be true.

And if you’re somewhere in the middle — not sure whether what you experienced qualifies, not sure whether you’re being “too sensitive,” not sure what you even feel about your family — that uncertainty is not weakness. It’s the beginning of honest inquiry. The most important thing you can do is stay curious about your own experience rather than rushing to a verdict about it.

Healing doesn’t ask you to resolve the sibling question. It asks you to tend to what’s yours — the grief, the confusion, the hypervigilance, the hunger for the family you deserved — with the care and steadiness that you’ve likely been extending to everyone around you for most of your life.

You can begin that now. You don’t have to wait for anyone to catch up.

If you’re ready to understand what’s underneath the relational patterns you’ve been living with, reaching out is a good first step. And if you’re not sure where to start, Fixing the Foundations offers a structured way to begin doing the deeper work on your own time.

Why the “High-Functioning” Sibling Often Carries the Most Unspoken Pain

Sarah is thirty-seven. She’s a project manager at a healthcare company, lives alone in a condo she bought herself, and has been in weekly therapy for four years. She can trace, with clinical precision, the through-lines of her childhood: the father who raged and then withdrew, the mother who managed him by disappearing into busyness, the years she spent being the “responsible one” — the kid who never created problems because the house already had enough.

She has done the work. She has read the books, filed the receipts of her own suffering, and learned to name what happened to her without minimizing it. And she can’t understand — not really, not in her body — why her younger brother refuses to acknowledge any of it. He’s warm, funny, functional. He talks about their parents like they were quirky but loving, and he gets a particular, careful blankness on his face whenever Sarah tries to go deeper. She doesn’t push anymore. But she carries the loneliness of being the only one in her family who seems to know what actually happened there.

What Sarah doesn’t always see — and what I see consistently in my work with women like her — is that the role that protected her brother also cost her something she’s still trying to name. She became the responsible one because she was capable enough, perceptive enough, and attuned enough to take it on. Her sensitivity was the very quality that made the family lean on her. And while her brother was allowed to remain relatively unburdened by the family’s emotional undercurrents, she absorbed them on his behalf — and on everyone else’s.

This is the hidden math of the high-functioning sibling: the child who carries the most is also the child most likely to be told she’s fine. After all, look at her. She’s managing. She’s successful. She’s in therapy. What she’s less likely to be told — and what she needs to hear — is that the managing was the wound. That the hypervigilance, the self-sufficiency, the iron grip on competence, are not signs of health. They’re the adaptations of a child who learned early that she couldn’t afford to fall apart, because no one would be there to help her up.

The sibling who appears most together often carries the most unspoken grief. Her brother’s comfort comes partly at the cost of her own. And her work — the real work — is not convincing him of what she knows. It’s learning to set down what she’s been carrying without anyone’s permission.

Bronfenbrenner’s observation has a shadow side that rarely gets discussed: what happens to the child who never had that person? Or who had it inconsistently — warmth mixed with volatility, love shot through with unpredictability? That child often becomes the driven adult who can’t stop achieving, who tends to everyone else with extraordinary competence, and who quietly wonders why, despite everything she’s built, she still doesn’t feel held. She’s still waiting for someone to be irrationally crazy about her. And she’s been waiting since childhood.

About the Author

Annie Wright

LMFT  ·  Relational Trauma Specialist  ·  W.W. Norton Author

Helping ambitious women finally feel as good as their résumé looks.

As a licensed psychotherapist, trauma-informed executive coach, and relational trauma specialist with over 15,000 clinical hours, she guides ambitious women — including Silicon Valley leaders, physicians, and entrepreneurs — in repairing the psychological foundations beneath their impressive lives. Annie is the founder and former CEO of Evergreen Counseling, a multimillion-dollar trauma-informed therapy center she built, scaled, and successfully exited. A regular contributor to Psychology Today, her expert commentary has appeared in Forbes, Business Insider, Inc., NBC, and The Information. She is currently writing her first book with W.W. Norton.

Work With Annie

Annie Wright

LMFT · 15,000+ Clinical Hours · W.W. Norton Author · Psychology Today Columnist

Annie Wright is a licensed psychotherapist, relational trauma specialist, and the founder and successfully exited CEO of a large California trauma-informed therapy center. A W.W. Norton published author, she writes the weekly Substack Strong & Stable and her work and expert opinions have appeared in NPR, NBC, Forbes, Business Insider, The Boston Globe, and The Information.

MORE ABOUT ANNIE

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