She wrote me that she felt terrorized. She travelled in the car – her bully was there. She ate at the kitchen table – her bully was there. This little five-year-old girl, Little Laura, told me that she had to walk to school with her bully. At school, her bully, with his predatory behaviour, was there. Every day. Feeling terrorized was something this little girl learned to live with.
The Hidden Family Epidemic We Can No Longer Ignore
The research is finally catching up
For years, sibling bullying has been one of the most overlooked forms of childhood mistreatment.
We have spent decades studying school bullying. We have developed policies, prevention programs and awareness campaigns. Yet, when the same behaviour happens inside the family home, it is frequently minimized, excused or dismissed.
We hear the familiar explanations:
“They’re just siblings.”
“All brothers and sisters fight.”
“He doesn’t really mean it.”
“She needs to toughen up.”
But what happens when the behaviour isn’t occasional fighting? What happens when one child repeatedly intimidates, humiliates, threatens or physically hurts another child?
What happens when home is no longer a safe place?
I began advocating for greater recognition of sibling bullying because I knew how deeply these experiences could affect a child. I also heard from adults who were struggling with depression, anxiety, self-harm, suicidal thoughts and complex post-traumatic stress symptoms, many of whom connected their difficulties to experiences growing up with an abusive sibling.
I wanted the research community to pay attention.
And it is.
1. One in four children: The international research
A significant international study published in February 2025 in the journal Child Abuse & Neglect examined sibling bullying among more than 30,000 children aged 10 and 12 across 18 countries.
Researchers Umar Toseeb, Emre Deniz and Nathalie Noret investigated how frequently children experienced physical and verbal bullying by siblings.
The findings were striking.
28% of children experienced sibling bullying victimization.
That is approximately one in four children.
The researchers defined the reported experiences as being physically hurt or called unkind names by a sibling more than three times during the previous month, excluding ordinary fighting and play fighting.
The prevalence varied between countries, ranging from 9% to 59%.
This is important because it demonstrates that sibling bullying is not simply a problem affecting a handful of families. It is a widespread childhood experience across different countries and cultures.
The researchers also found that positive experiences within the home, neighbourhood and school were generally associated with lower odds of sibling bullying victimization.
This gives us another important message: the environment surrounding children matters.
We cannot simply tell children to get along. We need to create family environments where aggression is recognized, boundaries are respected and children feel safe.
2. The long-term mental health consequences
One of the most important studies in this area was published in 2019 in Frontiers in Psychiatry.
The research, led by Dr. Slava Dantchev and including Professor Dieter Wolke, Matthew Hickman, Jon Heron and Stanley Zammit, examined the independent and cumulative effects of sibling and peer bullying.
The researchers used data from the Avon Longitudinal Study of Parents and Children (ALSPAC), a long-term UK birth cohort.
The original cohort included approximately 14,000 pregnancies. However, the particular analysis included up to 3,881 young people with relevant follow-up information.
Children reported their experiences of sibling and peer bullying at approximately age 12. Researchers subsequently examined mental health outcomes at ages 18 and 24.
The findings were concerning.
At age 24, children who had experienced sibling bullying showed increased odds of:
- Suicidal ideation.
- Suicidal self-harm.
- Clinical depression, particularly among those who were both victims and perpetrators of sibling bullying.
The researchers found that children who were sibling bullying victims had 1.52 times the odds of suicidal ideation compared with children who were not involved in sibling bullying.
They also had 2.20 times the odds of suicidal self-harm.
Young people who were both victims and perpetrators had 1.91 times the odds of clinical depression.
These associations remained even after researchers adjusted for several childhood factors, including peer bullying, earlier mental health difficulties, maltreatment and domestic violence.
This is significant.
The findings suggest that sibling bullying can have consequences that extend well beyond childhood, even when researchers account for other difficult experiences in a child’s life.
3. When bullying happens at home and at school
One of the most important findings in the 2019 research concerned children who experienced bullying in both environments.
Think about what that means.
A child is bullied at home by a sibling. They then go to school and experience bullying from their peers.
Where do they feel safe?
There is no real escape.
The researchers found that children exposed to both sibling and peer bullying had:
- Nearly twice the odds of clinical depression.
- More than twice the odds of suicidal ideation.
- More than three times the odds of suicidal self-harm.
This is what makes sibling bullying particularly concerning.
School bullying is devastating enough. But when the family home becomes another environment where a child experiences repeated intimidation, the child may have nowhere to recover emotionally.
Home should be a place of safety, not another place where a child has to anticipate the next incident.
4. Sibling rivalry versus sibling bullying: There is a difference
This distinction is essential.
Not every disagreement between siblings is bullying. Children argue, compete, become jealous and occasionally hurt one another’s feelings.
Sibling rivalry is generally characterized by disagreements, competition and conflict between children who have relatively equal power within the relationship.
Sibling bullying is different.
It involves repeated harmful behaviour, an intention to hurt or intimidate, and a power imbalance.
The power imbalance may be physical, psychological, social or emotional. One child may be older, stronger, more intimidating or better able to manipulate the family situation.
The behaviour may include:
- Repeated physical aggression, hitting, kicking or pushing.
- Threats and intimidation.
- Name-calling and humiliation.
- Deliberate exclusion and rejection.
- Destroying or taking possessions.
- Manipulation, coercion and psychological control.
The defining issue is not simply whether siblings fight.
It is the pattern of behaviour.
Is one child repeatedly targeted? Is one child afraid of the other? Does one sibling have power over the other? Is the behaviour causing distress and continuing despite the victim’s objections?
These are important questions.
And we need to stop using the word rivalry to excuse repeated harmful behaviour.
5. The family home: Where children should feel safest
One of the reasons sibling bullying is so difficult to address is that it happens within a relationship children do not choose.
Children cannot simply leave their families.
They share bedrooms, bathrooms, kitchens, vehicles, family gatherings and everyday routines.
They may be expected to play together, share possessions and spend time together even when one child is frightened of the other.
Unlike school, there is often no established system for reporting sibling bullying. There may be no formal intervention, no consequences and no outside adult who recognizes what is happening.
The child may learn to stay quiet.
They may become hypervigilant, constantly watching the other sibling’s behaviour and anticipating what might happen next.
They may begin to believe that their feelings do not matter or that they are somehow responsible for the mistreatment.
And sometimes, the adults who should protect them simply do not see it.
6. Parents and denial: Why intervention matters
Sibling bullying often becomes normalized within families.
Parents may interpret repeated aggression as ordinary childhood conflict. They may assume the children will work it out themselves.
Sometimes they are aware of the behaviour but do not recognize its seriousness.
Other times, they may actively minimize what is happening.
Dr. Wolke and colleagues have repeatedly drawn attention to the fact that sibling bullying can take place without parents fully recognizing its extent.
This is where parental intervention becomes critical.
Children need to understand that aggression, humiliation and intimidation are not acceptable ways to relate to another person.
Parents should not expect a child who is being targeted to simply tolerate the behaviour.
Nor should they automatically insist that both children are equally responsible.
A child who repeatedly hurts another child needs boundaries, supervision and appropriate intervention. A child who is being targeted needs protection and reassurance.
The goal is not to force siblings to become friends.
The goal is to make the home safe.
7. A new body of research: What we are learning in 2026
In September 2026, a new scoping review and meta-analysis was published in Trauma, Violence & Abuse.
Researchers Naiqi Tian and Mengtong Chen reviewed 117 studies examining sibling bullying, aggression and abuse.
Their findings further demonstrate how widespread the issue is.
The pooled estimates included:
- 37.7% experiencing sibling victimization.
- 35.8% engaging in perpetration.
- 33.3% involved in sibling aggression or abuse overall.
Importantly, the researchers also identified trauma-related symptoms as a significant outcome associated with sibling aggression and abuse.
The study brings together a substantial body of evidence and reinforces the need to recognize sibling mistreatment as an important area of childhood research and intervention.
The terminology used in this research is also important. Sibling aggression, bullying and abuse overlap, but they are not necessarily interchangeable. The severity, frequency, power imbalance and nature of the behaviour all matter.
We need to understand the full spectrum of experiences rather than dismissing everything as sibling rivalry.
8. The consequences can extend into adulthood
We need to look beyond childhood.
The sibling relationship is potentially one of the longest relationships in a person’s life.
It can extend from early childhood into adulthood, through parenthood, retirement and old age.
For some people, that relationship becomes a source of companionship and support.
For others, it remains a source of fear, rejection, conflict and emotional distress.
Adults who experienced repeated sibling mistreatment may continue to struggle with trust, self-worth, anxiety, depression, relationship difficulties and trauma-related symptoms.
Not everyone will experience these consequences, and we should never assume that a particular mental health diagnosis was caused by sibling bullying alone.
But we should also stop pretending that childhood experiences within the family cannot have lasting effects.
They can.
And the research is giving us increasingly strong reasons to take these experiences seriously.
9. What needs to change?
We need a much greater awareness of sibling bullying among:
- Parents and caregivers.
- Teachers and school administrators.
- Psychologists and counsellors.
- Physicians and other medical professionals.
- Researchers and policymakers.
We also need better screening, education and intervention.
When a child presents with anxiety, depression, behavioural difficulties or unexplained distress, professionals should consider asking about the child’s experiences at home, including relationships with siblings.
Parents need to understand that repeated aggression is not automatically normal sibling behaviour.
Children need to know that they deserve to feel safe in their own homes.
And adults who experienced sibling bullying need to know that their experiences matter, even if nobody recognized them at the time.
We can no longer ignore sibling bullying
I started this journey because I wanted people to understand something that had been overlooked for far too long.
Sibling bullying is common.
It can be repeated, deliberate and deeply damaging.
It can affect a child’s sense of safety, their relationships and their mental health. Its effects may continue into adulthood.
The research is growing. The international evidence is expanding. We now have longitudinal studies examining outcomes years after childhood and a growing body of research bringing together findings from around the world.
Yet, the conversation is still not where it needs to be.
We need to stop dismissing sibling bullying as a normal part of growing up.
We need to recognize the difference between sibling conflict and repeated abuse.
And most importantly, we need to listen to the children who are telling us they are afraid.
No child should have to live in fear of their own sibling.
It is time we started talking about it.
— Laura Corbeth
Research and Resources
Wolke, D., Tippett, N., & Dantchev, S. (2015). Bullying in the Family: Sibling Bullying. The Lancet Psychiatry, 2(10), 917–929.
https://doi.org/10.1016/S2215-0366(15)00262-XThis is pretty important. I am hopeful that with the new study, there will finally be a focus on sibling bullying.
Dantchev, S., Hickman, M., Heron, J., Zammit, S., & Wolke, D. (2019). The Independent and Cumulative Effects of Sibling and Peer Bullying in Childhood on Depression, Anxiety, Suicidal Ideation, and Self-Harm in Adulthood. Frontiers in Psychiatry, 10, 651.
https://doi.org/10.3389/fpsyt.2019.00651
Toseeb, U., Deniz, E., & Noret, N. F. (2025). The Prevalence and Correlates of Sibling Bullying Victimisation in Early Adolescence: An Investigation of over 30,000 Adolescents in 18 Countries. Child Abuse & Neglect, 160, 107211.
https://doi.org/10.1016/j.chiabu.2024.107211
Tian, N., & Chen, M. (2026). Sibling Bullying, Aggression and Abuse in Childhood and Adolescence: A Scoping Review and Meta-Analysis of Prevalence, Predictors, and Outcomes. Trauma, Violence & Abuse.
https://doi.org/10.1177/15248380261487140