Overview

When one child in a family transitions, or later detransitions, attention usually goes to that child and their parents. Their brothers and sisters get far less of it. Yet siblings are often the people who share a bedroom, a school and a social world with the young person. They are asked to learn a new name, to explain the change to friends, and sometimes to keep their own doubts to themselves. Years later, when a sibling detransitions, they may be the first to notice and the last to be asked how they feel.

This page covers what is known about siblings' experiences. It looks at the small research literature, at accounts from detransitioners and trans-identified people on Reddit, at sibling clusters (more than one child in a family taking on a trans identity), at siblings as a source of support, and at family therapy approaches. The evidence is thin. Most published studies of siblings have fewer than 20 participants, were recruited through gender-affirming clinics or networks, and asked only about siblings who were still trans-identified. No published study we found looks at siblings of detransitioners. The accounts below are a small, self-selected sample and should be read as illustrations, not as typical experiences.

For the wider family picture, see Parents and Families and Parents' Experiences.

What the research says

Small qualitative studies

Most of what has been published about siblings comes from interviews with a handful of people:

• Wheeler et al. (2019) interviewed eight young people aged 11–25 whose sibling was gender-diverse, recruited mainly through the UK's former Gender Identity Development Service (GIDS), the NHS gender clinic for under-18s at the Tavistock and Portman NHS Foundation Trust in London. The researchers described a "process of adjustment". Learning more about trans issues helped siblings take on supportive roles, but it also brought significant fears about their sibling's wellbeing and about the relationship itself (Wheeler et al. 2019).
• Parker and Davis-McCabe (2021) interviewed 17 Western Australian siblings aged 14–26. They reported having to act as a go-between, managing conflict, keeping their sibling's identity secret from people who didn't know, and holding back their own negative emotions. Many also described closer relationships. Sixteen of the 17 said the experience had affected their mental health or caused difficulties in their relationships, and support for it was rarely available (Parker & Davis-McCabe 2021).
• A 2024 scoping review (a structured map of what research exists on a question) by Klepper and colleagues found only nine relevant articles. Siblings of trans and nonbinary youth "lacked knowledge" and support for their own understanding, and "may experience unique stressors" around their sibling's changing identity. None of the studies tested any intervention for siblings (Klepper et al. 2024).

These studies were written within a gender-affirming framework. Siblings' worries are generally treated as an adjustment to be worked through, not as possible insight into whether transition is right for their brother or sister. They tell us that siblings carry a real burden. They tell us very little about how often siblings' concerns turned out to be justified.

Younger siblings and ideas about sex

One of the few quantitative findings about siblings comes from the TransYouth Project, a US study led by psychologist Kristina Olson that has followed socially transitioned children since the mid-2010s. (Social transition means changing a child's name, pronouns, clothing and presentation without medical treatment; see Social Transition of Young Children.)

In a 2018 study, Anne Fast and Olson compared three groups of 3- to 5-year-olds: 36 socially transitioned children, 36 matched controls, and 24 siblings of transgender or gender-nonconforming children. The groups did not differ in gender preferences or behaviour. However, the published abstract reports that "both transgender children and siblings were less likely than controls to believe that other people's gender is stable" (Fast & Olson 2018). Put simply, preschoolers whose brother or sister had transitioned were more likely to say that a person's sex category can change over a lifetime.

Researchers read this finding in different ways:

• From an affirming view, this is a more flexible and accurate understanding of gender, learned from family experience.
• From a sex-realist view, it shows that a sibling's transition can teach very young children something false: that a person can change sex. At ages 3 to 5, children are still working out gender constancy, the understanding that being a boy or a girl does not change with clothes, hairstyle or time. A family narrative in which a brother "became" a sister may unsettle that understanding while it is still forming.

A larger 2019 TransYouth Project paper found that 189 cisgender siblings did not differ from unrelated controls in their own gender identity or preferences. The authors argued this suggests "there likely is not a unique gender socialization experience in the homes of transgender children" (Gülgöz et al. 2019). Both findings come from families recruited because they had supported a young child's social transition, and the siblings were not followed into adolescence, so neither study can say how siblings' views develop later.

Living alongside a sibling's transition

When attention shifts

Families often reorganise around a child in crisis, and a sibling's transition can bring appointments, school meetings, worries about suicide risk and conflict between parents. Siblings in the Australian study described suppressing their own feelings so as not to add to the strain (Parker & Davis-McCabe 2021). Some commenters on /r/detrans use the term "glass child", which the writer Alicia Maples popularised in a 2010 TEDx talk. It describes a sibling of a high-needs child whom parents "look right through" while their attention is taken up elsewhere (WBUR 2026). One detransitioned woman, whose own brother had genital surgery and then blocked his whole family, wrote to another worried sibling:

It’s difficult being a sibling of someone with autism and mental illness. “Glass sibling” is what it’s sometimes called. Just know you’re not alone and none of it is in your control or your fault. —Antiquatedfish, detrans female

The point applies both ways. In a family where one child struggles with neglect or a parent's preference for the other sex, several of the children may be affected at once (see Trauma).

Being asked to use a new name and pronouns

Siblings are usually expected to adopt a new name and pronouns quickly, often before they understand why. Younger children may get it "wrong" for a long time, and for them the old name and sex may simply be the truth. A trans-identified man described his younger sister copying a grandmother who refused the change:

I came out when I was 11 and she was 8. We had some issues, for example my (transphobic) grandma would visit and misgender and deadname me, since my sister didn’t understand what was going on she would do it with her. —wormmiilk, ftm

On trans forums, a sibling's use of the new name is often treated as the test of their loyalty. This puts siblings, especially young ones, in a bind. Questioning the change can be read as rejection, so many go along with it whatever they privately think. For a fuller discussion, see Names and Pronouns.

Feeling unable to voice doubts

A recurring theme in sibling accounts on /r/detrans is having concerns but not being able to say them. That can be because parents have fully committed to the transition, because clinicians have warned that doubt is dangerous, or because the trans sibling may cut contact. A stepsister who did raise her concerns wrote:

I think I went in too hard and scared him, overwhelming him with information. he just shut down and I don't think a lot of it went in. so he kind of avoids me now. —fukinfrogslegs, desisted female

The same pressure can run the other way. Some detransitioners describe siblings who pushed them into a trans identity. One desisted woman said her eldest sibling called her an "egg" (online slang for someone said to be trans without yet knowing it; see Egg Cracking):

the oldest one said i was an "egg" (because i.. looked uncomfortable in girl clothes -_-) and forced me to "come out" before i had even really been identifying that way —2cal4u, desisted female

Sibling clusters

What families report

Some families report more than one child identifying as trans, sometimes within a few years of each other. On /r/detrans, these accounts often come from an older sibling who identified first and who now believes the younger ones followed:

I'm desisted, but both my younger siblings transitioned medically, and it seems clear that the biggest difference between me and them was their susceptibility to social pressure. —novaskyd, desisted female

My little sibling (female) started identifying as a boy because of me :( luckily my mother told me shes not putting him on testosterone for a long time because, and I quote "you just seemed so much more sure". It's gonna be kinda awkward when I tell her I'm detransitioning, lol. —Top_Spinach_5329, detrans female

The same commenter later added that her younger sibling's identical twin identifies as nonbinary but, in her words, is "not in as deep." When one woman described three female siblings in one home all identifying as trans men, a detransitioned man asked:

There are not 1, not 2, but 3 FTM children/youth in one home? Your parents didn't think that was a bit strange and perhaps a bit of a contagion? Or, worse, did they steer you in that direction? —Hedera_Thorn, detrans male

Admiration for an older sibling is a plausible route. One detransitioned woman wrote that she "would have listened to my older brother. I practically worshipped him growing up" (RealityGirlZine, detrans female). Children copy older siblings' hobbies, music and opinions. Taking on an older sibling's identity framework, especially one that brings attention and praise at home, fits a familiar pattern. Trans commenters describe the same thing in a positive light, for example a trans woman whose sister and she "came out to each other at the same time" and who called it "such a special bond" (CoveCreates, mtf).

What the research can and cannot say

There is no good estimate of how common sibling clusters are today. The older evidence comes from adult clinic populations, mostly before the large rise in adolescent referrals:

These figures point in different directions. The twin case reports suggest some heritable component. The Swedish register, which is far less affected by selective reporting, found no same-sex twin pairs in which both had a diagnosis and very low sibling concordance. None of these studies can separate shared genes from a shared home: siblings share parents, trauma, family attitudes to sex roles and, increasingly, the same online spaces.

The cluster pattern most often discussed today concerns friendship groups rather than siblings. In Lisa Littman's 2018 survey of parents, which proposed the hypothesis of rapid-onset gender dysphoria (ROGD), parents reported that in 36.8% of the friendship groups described, the majority of members had become trans-identified (Littman 2018). That study relied on parent reports, has been heavily criticised, and focused on friendship groups rather than siblings. Whether peer influence works the same way between siblings has not been studied. See Social Contagion and Peer Influence and Rapid-Onset Gender Dysphoria.

A careful conclusion: the family accounts are consistent with sibling influence and shared family factors, but they cannot establish how often one sibling's identification leads to another's. Families who would not see it that way, including those who see multiple trans children as evidence of a shared innate trait, are less likely to post on /r/detrans.

When a sibling detransitions

Guilt in the older sibling

Detransitioners who identified first sometimes carry heavy guilt for siblings who followed them and did not come back:

I honestly feel guilty because BOTH my younger siblings identified as trans after I did and imo I am the one who "affirmed" them into it. Me detransitioning didn't de-affirm them though. And now I can't honestly discuss my opinions with them without getting cut off. I care deeply about them. But there is this chasm now, cutting off our bond and our ability to be honest with each other. —novaskyd, desisted female

The asymmetry she describes matters. An identity a sibling once modelled does not necessarily go away when the model changes course. By then the younger sibling may have their own friends, clinicians and community invested in it, and a detransitioned sibling may be seen as a threat rather than a guide. Other commenters push back on the self-blame:

It’s not your fault, even if your actions somehow influenced these turn of events. —daddioflies665, desisted male

How siblings react

Accounts of siblings' reactions to a detransition vary widely. Some are relief, some indifference, and some feel like a second rejection. A sibling who was a vocal ally may experience the detransition as a betrayal of a cause they had taken on:

I think my sister doesnt like me anymore because of detransition. She was and is a huge advocate for me and other trans and queer people. She thought i was happy as man, and when i told her i actually wasnt, she stopped talking to me and now is uncomfortable around me. —jackolantern717, detrans female

A sibling who is still trans-identified may try to fit the detransition into their own framework:

my brother is still ftm and he keeps being like ok but we all know youre like nonbinary or something. and i have to bite my tongue so i dont go like baby i do not think that is a thing that exists —anthonypreacher, detrans female

Others describe relief, and the end of a tension that had never been spoken:

The only person I speak to from my family is my older sister. I was worried she would be all "I told you so" too, but her response was more just... relief. —TCnup, detrans female (FTNBTF)

Humour can ease the change too. One desisted woman wrote that her brothers "make jokes about telling their kids to call me uncle-aunt" (sleeper_agent02, desisted female). Another found that a sister who is a doctor was "the one person to accept my detransition" (chef-rach-bitch, socially trans, regrets transition).

Young children relearning

A common worry is how to explain a detransition to small children who have only known the transitioned identity. One detransitioned woman described young cousins, who in her culture are called brothers and sisters, adjusting without difficulty:

My cousin who knew me as anything but a boy since she was born understood everything without hesitation, because she loved me as her relative, not as some gender. —thistle_ev, detrans female

Her older cousin, then 7, even remembered her birth name without being told. Accounts like this suggest that for many young children the bond matters more than the label, and that a simple, honest explanation from an adult they trust is often enough.

Siblings as support

During transition

Trans-identified people often describe a sibling as their most reliable ally, sometimes the only family member who used their new name. In one 2025 interview study, 52 trans youth (mostly young people of colour) described siblings who helped them when parents were unsupportive, through "nonchalant" acceptance and by not outing them to other relatives (Alexander et al. 2025). The Klepper review found sibling support was associated with less depression and suicidal ideation, an association that does not by itself show cause and effect (Klepper et al. 2024).

The other side appears in trans forums too: siblings who refuse the new name, or who make acceptance conditional. One trans man wrote of a sister who:

refused to use my name and pronouns until my name and gender change certificate arrived, because, according to her, she "hadn't fully accepted it" and wouldn't "accept it" till my certificate arrived —NoMango7188, ftm

During detransition

For detransitioners, a sibling who stayed steady, neither cheering the transition on nor fighting it, comes up repeatedly as what helped. One detransitioned woman described her brother this way:

When I told my brother I was detransitioning, he responded with “Yeah, I figure you would.” … What he did was talk to me, he let me live my life and he was there when I figured my own stuff out. —ReasonableSpud, detrans female

Advice on /r/detrans for siblings worried about a trans-identified brother or sister tends to follow the same lines. Build the relationship on things other than gender. Be honest without campaigning. Make it clear that the door stays open:

Being honest with my younger brother has been a huge source of support in my life, strong sibling relationships are truly a blessing. Don't worry about "intervening" as much as being honest and heart-to-heart with your sibling. —Affection-Angel, detrans female

Your goal shouldn't be to induce your sibling to detransition but open a dialogue for his self-led exploration of themes: what needs are met through my transition? What needs aren't? —Takeshold, detrans and female

The same commenter suggested that gender should come up only a small part of the time in such a relationship, and that an openly detransitioned sibling can serve as "a signpost if he ever needs one." This reflects an insight found across many detransition accounts: being pushed tends to harden an identity, while a relationship that doesn't depend on it leaves room to reconsider. For more, see Supporting a Detransitioning Child and Healing and Recovery.

Family therapy approaches

The family as a system

Family systems therapy treats a young person's distress as part of a wider pattern of relationships rather than as a problem inside one person. From this view, siblings belong in the room. They know the family from the inside, and the way a family responds to one child's gender distress shapes every child in it. One detransitioned woman, reflecting on her own case, wrote:

a general examination of the family dynamic would probably be really good in most cases (assuming the pros don't get distracted by the trans factor). —trialeterror, detrans female 🦎

She added that families should "be open to the possibility that change may be required from more than just the child."

Exploratory and affirming models

Two broad systemic approaches exist:

• Gender-exploratory therapy: open-ended psychotherapy that explores the possible sources of gender distress, such as trauma, sexuality, autism or family dynamics, without assuming in advance that transition is the answer. Family therapist Anastassis Spiliadis set out a "Gender Exploratory Model" grounded in a "systemic-developmental framework" that explicitly includes the family and moves away from "affirmative" versus "reparative" extremes (Spiliadis 2019). See Gender-Exploratory Therapy.
• Affirmative family therapy: models such as Jean Malpas's "multi-dimensional family approach" at the Ackerman Institute's Gender & Family Project (Malpas 2011) aim to help families accept and support a child's stated identity. A 2025 paper argued for bringing siblings into "affirmative systemic therapy" as "mediators, educators, and advocates" (Van Vliet & Rabiau 2025). In this model, the sibling's role is to support the identity, not to question it.

The difference matters for siblings. In an affirming model, a brother's doubts are something to be resolved through education. In an exploratory model, those doubts are information: he may be the person who remembers how the change began, which friends were involved, or what was happening at home at the time.

Official guidance

England's independent Cass Review (2024), the review of gender services for under-18s led by paediatrician Hilary Cass, recommended that standard psychological treatment for gender-related distress "should include support for parents/carers and siblings as appropriate" (Recommendation 3, Cass Review 2024). This is one of the few places where siblings appear in clinical guidance at all. No trial of any sibling-focused intervention has been published (Klepper et al. 2024). Families looking for therapists who work this way can check the support directory.

Limitations

• Very little data. The published sibling studies each have 8–52 participants, recruited through affirming clinics or networks. No study looks at siblings of detransitioners or follows siblings over time.
• Selection in the accounts. Reddit comments come from people motivated to post. On /r/detrans those are mostly detransitioners and family members with concerns; on trans forums, trans-identified people. Neither group represents siblings in general.
• Clusters are not measured. No modern study estimates how often more than one child in a family becomes trans-identified, or why. The twin and register studies above mostly predate the recent rise in adolescent referrals.
• Competing explanations. Shared genes, shared family environment, imitation and shared online exposure all predict some clustering, and current data cannot tell them apart.

References

• Alexander, K., Robinson, B. A., & Stone, A. L. (2025). Unionized Against Cisnormativity: How Siblings of Transgender Youth Divest from Family Gender Norms. Gender & Society. source.
• Cass, H. (2024). Independent Review of Gender Identity Services for Children and Young People: Final Report. NHS England. source.
• Fast, A. A., & Olson, K. R. (2018). Gender Development in Transgender Preschool Children. Child Development, 89(2), 620–637. source.
• Gómez-Gil, E., Esteva, I., Almaraz, M. C., Pasaro, E., Segovia, S., & Guillamon, A. (2010). Familiality of Gender Identity Disorder in Non-Twin Siblings. Archives of Sexual Behavior, 39(2), 546–552. source.
• Gülgöz, S., et al. (2019). Similarity in transgender and cisgender children's gender development. Proceedings of the National Academy of Sciences (PNAS). source.
• Heylens, G., De Cuypere, G., Zucker, K. J., et al. (2012). Gender Identity Disorder in Twins: A Review of the Case Report Literature. Journal of Sexual Medicine, 9(3), 751–757. source.
• Karamanis, G., Karalexi, M., White, R., et al. (2022). Gender dysphoria in twins: a register-based population study. Scientific Reports, 12, 13439. source.
• Klepper, M., Bosse, J., Flores, D. D., & Sanders, R. (2024). Sibling Support for Transgender and Gender-Diverse Youth: A Scoping Review. Journal of Adolescent Health, 75(4), 543–552. source.
• Littman, L. (2018). Rapid-onset gender dysphoria in adolescents and young adults: A study of parental reports. PLOS ONE. study page, source.
• Malpas, J. (2011). Between Pink and Blue: A Multi-Dimensional Family Approach to Gender Nonconforming Children and their Families. Family Process, 50(4), 453–470. source.
• Parker, E., & Davis-McCabe, C. (2021). The sibling experience: growing up with a trans sibling. Australian Journal of Psychology, 73(2), 188–199. source.
• Spiliadis, A. (2019). Towards a Gender Exploratory Model: slowing things down, opening things up and exploring identity development. Metalogos Systemic Therapy Journal, 35. source.
• Trapp, B. (2026). My twin brother was disabled, but I don't consider myself a 'glass child'. WBUR Cognoscenti. source.
• Van Vliet, A., & Rabiau, M. (2025). Intragenerational Support for Gender-Questioning and Trans Youth: Centering the Sibling Subsystem in Affirmative Systemic Therapy. Journal of Marital and Family Therapy. source.
• Wheeler, N. L., Langton, T., Lidster, E., & Dallos, R. (2019). Understanding more about how young people make sense of their siblings changing gender identity. Clinical Child Psychology and Psychiatry, 24(2), 258–276. source.