Sibling Bullying: The Moments That Last Into Adulthood

The short answer: what passes between siblings is the parents’ business. If one child is regularly hurt or humiliated by another, step in: in our family, we don’t humiliate each other.

Many adults carry a sentence from a brother or sister for decades. The one who said it often does not remember it at all. The one who heard it remembers everything: the words, the place, the faces, and very often the parent who was a few metres away and said nothing.

My view: what passes between siblings is the parents’ business. Not every squabble, but every humiliation. A child who is mocked by a sibling while an adult looks away learns two things at once: that they are worth less, and that nobody will protect them. And a hair separates ordinary fighting from cruelty. Parents must know which side of it their children are on.

Why sibling moments last

Brothers and sisters are often the longest relationships of our lives. They know us before we can talk, and often long after our parents are gone. And because they are so close, what passes between them, the kindness and the cruelty, goes deep.

A word from a stranger can be forgotten. A word from a brother, said again and again, can become part of how a child sees themselves. I’m the stupid one. I’m the ugly one. I’m the one nobody wanted.

Children also notice how their parents respond. Did a parent step in? Did they take it seriously? Did they laugh along? Did they always side with the older one, or the younger, or the “easy” one? Often, what stays most is not only the sibling’s words, but the silence of the adult who heard them.

Ordinary conflict, and something more

Siblings fight. They argue over toys, space, attention, fairness. That is ordinary, and it can even teach children how to negotiate, share and make up.

But some sibling behaviour goes further: repeated teasing that humiliates, physical hurting, excluding, threatening, cruel words aimed at a sibling’s body, intelligence, or worth. When this happens over and over, and one child is always on the receiving end, it is bullying.

Research suggests it matters. A large UK study of more than 6,900 young people found that those who were frequently bullied by a sibling at age 12 were about twice as likely to have depression at 18, and more likely to self-harm, than those who were not (Bowes and colleagues 2014). The researchers concluded that “being bullied by a sibling is a potential risk factor for depression and self-harm in early adulthood.”

Sibling cruelty is sometimes dismissed as “just kids being kids.” The research suggests it deserves the same seriousness as bullying at school.

What the cruel sibling may be carrying

It can help to look at the child who hurts, too. A sibling who is cruel is sometimes a child in pain: jealous of attention, feeling less loved, struggling at school, copying what they see between the adults, or being hurt elsewhere themselves. And sometimes a child is cruel because it worked and nobody stopped it.

This does not excuse cruelty. But it tells parents where to look. Stopping the behaviour is the first step. Understanding what is underneath it is the second.

The labels that stick

Sometimes the lasting harm comes not from siblings, but from comparisons made by adults. “Why can’t you be more like your sister?” “He’s the clever one, she’s the pretty one.” “She’s always been the difficult child.”

Children absorb these labels. They often live up, or down, to them. And siblings use them against each other.

A child labelled “the difficult one” at six may still feel it at forty, at the family dinner table.

What parents can do now

Take it seriously. If one child is regularly hurt by another, step in. “In our family, we don’t humiliate each other. That stops now.”

Protect the target. Make sure the child who is being hurt knows you see it, and that you are on their side.

Look under the behaviour. Spend time with the child who is being cruel. What is going on for them? Do they need more attention, help, or support?

Avoid comparisons. Speak about each child on their own terms. Celebrate each child’s strengths without setting them against each other.

Watch the adult model. Children who see contempt between parents often use it with siblings. Children who see kindness are more likely to show it.

Repair old moments. If you know there was a moment when you didn’t protect one child, it is not too late. Even years later, a parent saying “I should have stepped in, and I didn’t. I’m sorry” can ease something that has been held for a long time.

If you carry a sibling moment

As you read this, you may have remembered something of your own. A word from a brother. A game that was not a game. A parent who looked away.

It is worth knowing that you are not being oversensitive. Sibling wounds are real, and they can shape how you parent your own children, especially when your children fight. Talking about the memory, with a partner, a friend, a sibling if it is safe, or a counsellor, can help loosen its grip.

When to get help

If a child is being repeatedly hurt by a sibling, seems anxious, low, or withdrawn, or talks about hurting themselves, talk to a doctor or school counsellor. If a child is in danger, act immediately and call your local emergency number.

A question to carry

Tonight, think about your children together. Ask yourself:

What moment between them, today, might one of them still remember in thirty years?

You cannot control every word they say to each other. But you can make sure that, when it matters, an adult steps in. That, too, is a moment children remember.

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Next step

Look at one real evening. Answer a few questions about what happened between your children, and get a 7-day sheet to try. Try Tonight’s log →

Sources

• Bowes, L. and colleagues (2014). Sibling bullying and risk of depression, anxiety, and self-harm: a prospective cohort study. Pediatrics, 134(4), e1032–e1039. PubMed