In the grand constellation of human relationships, siblings are ever-present and strangely overlooked. We may have shared bunk beds or fought over dinner scraps, yet as adults, sibling bonds can become emotionally charged, distant, or even estranged.
“Your siblings are the people you’re likely to know the longest in your life,” says Dr Geoffrey Greif, a professor at the University of Maryland School of Social Work and co-author of Adult Sibling Relationships. “You’ll likely know them longer than your parents, longer than your spouse, longer than your friends.”
Greif has spent decades studying how siblings shape our lives and our identities. One of his core ideas is that “nobody grows up in the same family”. Even children raised under the same roof can inhabit completely different emotional worlds. “I’ve never had the experience of having me as a sibling,” he says. Birth order, shifting parental relationships, financial change, illness, trauma, even time itself – all of these shape how children are parented, and how they see their siblings.
“There’s no one truth in any one family,” Greif says. “Even in a loving household, you’re being parented by people who are changing all the time.”
Most adult siblings, Greif says, exist somewhere between closeness and conflict. He names three defining characteristics of sibling relationships: affection, ambivalence, and ambiguity. Some siblings talk daily; others drift apart and don’t talk for years. Many hover in an undefined middle ground – bound by blood but estranged by personality or pain.
Research on this dynamic is surprisingly scant. Siblings are hard to study because they are hard to standardise, and every family constellation is different: being the eldest of three girls isn’t comparable to being the eldest boy in a family of seven, for example, and families have different value systems and lifestyles. Much of the existing research into siblings relies on individual interviews, which often means only one side of the sibling story is being told.
But the research we do have paints a striking picture. One study found that the warmth a person felt from their sibling at 23 predicted lower depression in midlife. Another, tracking participants for 30 years, found that closeness with a sibling in childhood – but not with a parent – predicted emotional wellbeing at 50. A study of more than a million Swedes found that one’s risk of dying from a heart attack rose after a sibling’s death, not only due to shared genetics, but also because of the emotional toll of losing such a central figure in their lives.
Even distant siblings can provide what Greif calls “instrumental support”, such as help with ageing parents. When these ties rupture, the loss is both emotional and operational.
Difficulties often surface during moments of family transition – especially illness or death. “You can go off in your 20s and climb mountains and not need to interact with your siblings,” Greif says. “But when your parents are in their 70s or 80s and they need care, suddenly you’re back in a room with them, trying to figure out how to share responsibility.”
These reunions often reopen old wounds. Birth order hierarchies reassert themselves. Resentments return. The golden child may still act entitled; the scapegoat still feels excluded. And when in-laws, grandchildren, and property are added to the mix, it’s no longer just a sibling story. “It becomes a whole system,” Greif says. “And that’s where things can get really hard.”
Muireann* is estranged from her twin sister Saoirse*. Their parents had a tumultuous relationship and their mother was often left alone trying to care for the girls and work to keep the family afloat. Despite their mother’s best efforts, the girls were often left in situations that were unsafe, which resulted in emotional difficulties for both of them. Now in their late 30s, the women no longer speak.
“Our relationship was the most vital one I had through childhood. I can’t describe the heartache of not having a relationship with my sister,” she says. “We were super close from the beginning – talking to each other across our cots. It was magic for a lot of our childhood.” In school, Saoirse was bullied, which caused a growing distance between them. “It broke her. I felt, in hindsight, really guilty for not standing up for her.”
Over time, their paths diverged – Muireann became fiercely independent, her sister grew increasingly reliant on their mother. Tensions escalated until, one Christmas, a violent altercation ended with Muireann locking her sister and mother inside the house to escape.
“I want to get back in touch with her,” Muireann says. “I just don’t think this should last forever. I spend a lot of time worrying for her. I wonder if she misses me.”
In Ireland, sibling estrangement violates the sacred narrative of family unity. “My mother would always say, ‘The worst thing that could happen is you kids not staying close,’” says Sadhbh* (44), who grew up with two brothers. “There’s still this blood-is-thicker-than-water thing. The biggest sin you can commit is to air your family’s dirty laundry by going no contact.”
But Sadhbh’s mother’s worst fear has been realised. What started as childhood slagging between Sadhbh and her brothers became a dysfunctional dynamic between the adult siblings where cruelty, verbal abuse, and aggressive competitiveness was normalised as “banter”. When Sadhbh started therapy as an adult, she realised the impact this dynamic was having on her self-esteem and anxiety.
“I never went to therapy for my childhood. I went for panic. And then the therapist was like, ‘Hang on. No, there’s a lot of stuff you think is normal, but it’s not normal’. I’ve had therapists ten years apart from each other repeat the same thing to me: ‘Stop talking to your family.’ And I was just like, ‘No, that’s not an option’.”
For years, Sadhbh tried address the dynamic with her brothers and invite them to have a more loving relationship, but they didn’t change how they spoke to her.
“My older brother, he just wants to poke and poke and poke and have a debate and win. It’s like he’s still a teenager who has to have this sibling rivalry. And I don’t have the energy for it. And I tried a lot with him, but it’s just exhausting. It’s just the same, and then there’s apologies and ‘Come on, you’re my sister, love you, let’s go for a drink – but his behaviour has not changed at all.”
Sadhbh cut off contact with her younger brother first, then her older brother a few years later. “I’m so bone sad and hurt, but that’s grief at a loss I’ve chosen. I’d rather be lonely as f**k and be safe – like emotionally safe.”
Sadhbh highlights how families often get stuck in unhealthy dynamics and prefer to let issues to fester rather than try to evolve and change. “You get scapegoated if you are trying to question things, evolve, call the dysfunction out. And often we just choose, ‘Well, I’d rather not be ostracised’. But then you’re just putting up with really unhealthy family dynamics.”
As a family therapist, adolescent mental health specialist and a former chair of the Family Therapy Association of Ireland, Dr Monica Whyte has worked extensively with individuals and families navigating complex relationships. She believes Irish history and culture plays a unique role in shaping how Irish families respond to conflict.
“There’s what I call a silencing pressure ... pressure to keep families quiet around certain things – around addiction, abuses of power, things like that. There’s a cultural pressure to be silent in order to keep up the family image. And that pressure often means people can’t talk about what’s really happening, even with their own siblings.
“The culture of silence in Irish families can’t be separated from our institutional history. For decades, we had state and church-run systems that divided up power and communication – there was no transparency, and no sharing of stories. That structure has left a mark on how families operate. Information is compartmentalised. Pain is hidden. And a lot of families learned that secrecy was a form of protection – even when it was causing damage.”
This cultural focus on the family can result in pressure on family members to tolerate mistreatment or even more serious breaches of trust and safety. “There’s often a huge loyalty to family, and it can feel like betrayal to speak up or step back,” says Whyte. “But some of the biggest breaches in families are the result of trauma – abuse, addiction, chaos. When someone walks away from their family, often it’s not because they’re giving up, but because they’re trying to survive. That can be very hard for Irish families to accept. There’s a lot of stigma still around going no contact. And often, when someone tries to set a boundary, the family sees it as rejection, not protection.”
The introduction of new people to the family can create issues. When sibling relationships become strained, in-laws are often part of the story, Greif says. “Most often, the complaints that come up are about relationships with mom and dad,” he says, “but right behind that is: who did my sibling marry?”
Romantic partners bring their own values, dynamics, and loyalties into the mix and these can shift the sibling dynamic. In these moments, the sibling at the centre of the in-laws often feels torn. “You can’t be neutral,” Greif says. “You’re the bridge between two people who would never have to interact if it weren’t for you. And that means you have to step up. You have to actively help navigate that relationship.”
Increasingly, one of the most volatile forces in sibling estrangement is political polarisation. “Let’s say I voted for Kamala Harris and my sister-in-law voted for Trump, and let’s say I have a trans child. I can’t stand the idea that someone in my family would support someone who doesn’t support my child’s rights.” He pauses. “There are lines that people just can’t cross.”
For some people, breaking off contact with a family member is a necessary act of self-preservation. But Greif worries about the long-term emotional costs – especially when those decisions are handed down to future generations.
“If I’m estranged from my brother, what message am I giving my children?” he asks. “That this is how we deal with conflict? That if something gets hard, we walk away?”
Family therapist Karen Gail Lewis has spent decades working with adult siblings in Washington DC. She has identified “four ghosts” – four hidden dynamics that shape and often sabotage adult sibling relationships. The first, frozen images, refers to the way we continue to see our siblings as they were decades ago. Lewis describes how her own brother still sees her as “Little Blanche”, the dutiful girl who couldn’t possibly rebel – an image that can feel infantilising.
While some frozen images are rooted in pain or conflict, others are born of admiration: the idealised frozen image. “Sometimes, we don’t resent our siblings – we revere them,” she says. “And when they fall from that pedestal – cheat on a spouse, vote differently, fail in some visible way – it can feel like a betrayal not just of trust, but of identity.”
Fionn* (41) idolised his sister growing up. Ailbhe* was five years older, and was confident and popular in a way that introverted and sensitive Fionn admired. When Fionn was in his mid-20s and his long-term girlfriend cheated on him, Ailbhe was his rock. It took him a long time to recover from the heartbreak and betrayal. Three years ago, when Fionn discovered that Ailbhe had cheated on her husband, he couldn’t bear to look at her.
“She saw how much that broke me and then did it to her husband – it shattered my faith in her and in relationships generally. I never, ever thought she’d do that to someone and it made me think I’d never be able to be sure about anyone.”
When Ailbhe’s husband discovered the affair, the couple decided to work through it and are still together, but Fionn didn’t speak to his sister for over a year. They’re now “civil” but Fionn admits he still finds it hard to reconcile the perfect image he had of his sister with what he now knows.
“Her husband has forgiven her, so I guess it doesn’t make sense why I can’t fully, but it’s hard,” says Fionn. “I wish I didn’t know. I miss her.” Her now or the image he had of her? “Both.”
The second of Lewis’s four ghosts is “crystallised roles”. These are the rigid family roles assigned in childhood – the smart one, the rebel, the clown – which, over time, calcify into identities we cannot shake. A woman cast as the “responsible one” may feel she must always hold everything together, while her “troublemaker” brother is never expected to contribute. Even when siblings try to swap roles – the rebel gets sober, the golden child burns out – the family story often resists updating.
The third is “unhealthy loyalty”. Lewis recalls a man who had once been a high achiever but, after losing his job during the recession, felt an unexpected sense of relief. “He said, ‘Now when I visit my family, I feel more comfortable. I’m not so different from them any more.’” For years, his success had made him feel like an outsider. Without knowing it, he had been holding himself back – out of love, perhaps, but love in a distorted form.
Finally, the fourth ghost is “sibling transference”, or the way we unconsciously replicate early sibling dynamics in our adult relationships with others. A woman who learned to manage her impulsive brother as a child may find herself drawn to a partner with similar traits. A man who felt invisible next to his overachieving sister may find himself triggered by competitive colleagues. We don’t necessarily marry our siblings, Lewis says, but we often re-enact our sibling roles with those closest to us.
Despite the deep significance of these dynamics, sibling therapy is not common. “Therapists aren’t trained to do this work,” says Lewis. “Psychology schools don’t teach sibling therapy. So even therapists who might be interested often don’t have the tools.” Lewis trains other therapists, and sees this specialisation as urgent. “I’m 81 in two weeks. I want this work to continue. I don’t charge for training – I just want my expenses covered. I trained therapists in Estonia last year. I’d love to come to Ireland if anyone’s interested.”
Lewis says many siblings who seek therapy together aren’t doing so from a place of harmony, and often, one sibling is driving the reconnection. “One says, ‘I haven’t talked to her in six years, but we ran into each other and she agreed to come once just to shut me up.’ But more often than not, they come back.”
The work is often brief but transformative. “Sibling therapy is often shorter than individual or couple therapy. People say, ‘I’ve been in therapy 20 years for my trauma.’ But if you never worked through how that trauma played out between you and your siblings, there’s still residue.”
Lewis is careful not to impose a one-size-fits-all notion of success on sibling therapy, saying, “Some siblings end up close. Others get to ‘We can be civil’. Some drop out of therapy and I think, ‘Well, that didn’t go anywhere,’ and months later I get a letter saying it changed their lives. You just never know.”
What she sees as most valuable is the opportunity to tell the truth and be heard. “When siblings talk – really talk – about what it was like growing up together, things shift. Not always into harmony. But into clarity. And that’s something most people never get to do.”
Whyte agrees that there needs to be more awareness and access to therapy that isn’t just focused on one person.
“In Ireland, we have a heavy reliance on individual models of therapy,” she explains. “That means you’re often working one-to-one, without hearing the different perspectives and stories within the family. So a lot of stories remain untold and unheard.”
Whyte practices systemic family therapy, a collaborative approach that works with family members together – siblings, parents, even grandparents – to understand relational patterns and make meaning of shared experiences. Unlike individual therapy, which focuses on internal emotional states and personal growth, systemic therapy examines how people interact, how roles are reinforced, and how patterns get repeated – often unconsciously -across generations.
“Systemic family therapy looks at how we live our lives in connection with others – our family of origin, but also the family we create for ourselves,” she says. “It’s not just about individual change. It’s about systemic change – looking at how we make meaning together, and how we can shift our shared dynamics.”
But sibling therapy also requires a therapist with the right orientation – and access to that expertise can be uneven across the country.
“If someone doesn’t live near a systemic therapist, they might only be offered individual therapy – psychodynamic, CBT, or otherwise – and those are valid approaches, but they don’t necessarily bring the family into the room,” Whyte says. “And that can limit what’s possible in terms of repair.”
Not every sibling story ends in reconciliation. For some people, like Sadhbh, distance feels like the only option to ensure her emotional safety. But Lewis and Greif believe that the stories we tell ourselves about our siblings – and the roles we play in theirs – can be rewritten, if we’re willing to listen.
“You can’t argue someone out of their pain,” Greif says. “If your sister says, ‘You never let me in your room as a kid,’ don’t say, ‘You were annoying’. Say, ‘I can understand why that hurt you’.”
For those who unable to access therapy, Lewis offers a free downloadable book called Are You a Sibling? with practical tools and advice, and a guide for therapists on running sibling retreats.
For individuals thinking of reaching out to a sibling they are estranged from, she recommends starting from a place of curiosity. “If you’re considering reconnecting, start by asking yourself, ‘What’s my frozen image? What role have I clung to? Am I holding myself back out of some warped sense of loyalty? Understanding yourself is the best place to start from.”
*The names of siblings in this piece have been changed to protect the anonymity of interviewees.
