The 4 surprising ways sibling rivalry can harm your long-term health

MANY of us think a bit of rivalry between siblings is harmless – normal even.

But research has shown that the line between rivalry and aggression tends to be pretty blurry.

Aggression between siblings can often be dismissed as harmless rivalry, researchers say

And it can harm your mental and physical health in the long-term.

Though our brothers and sisters can be close confidants, they are also natural competitors for our parents attention.

So while rivalry can foster unique talents and growth, it can also lead to jealousy and bickering.

“Too much of it can lead to aggression, bullying and even abuse and violence,” write Corinna Jenkins Tucker and Tanya Rouleau Whitworth, researchers from the Crimes Against Children Center at the University of New Hampshire.

They described aggressive behaviour as an an intent to cause harm, including physical pain and humiliation.

It goes beyond bickering and petty conflicts, crossing over into pushing, hitting or breaking cherished personal items, the researchers – whose work focuses on sibling dynamics, parenting and mental health – said.

 “Many behaviours between siblings fit this definition,” they told The Conversation.

Aggression between siblings is more common than you might think.

In 2013, Corrina and Tanya found that a third of US children under the age of 18 had been victimised by a sibling in the previous year.

“In fact, sibling aggression is the most common form of family violence, with more children victimized by a sibling than by a caregiver.

“It’s a form of family violence not talked about, despite its ubiquity,” they added.

Corrine and Tanya wrote: “The cause of sibling aggression can be rooted in family dynamics.

“Parents may model negative behaviours that are then repeated by children.”

Children might also become aggressive towards their sibling if they have low empathy or anger issues, the researchers said.

Corrina and Tanya pointed out how great efforts are made to stop bullying between peers, but parents tend to dismiss the same behaviours between their kids.

They sometimes blame the victimised sibling for provoking aggression or being too sensitive.

When sibling aggression becomes abuse

Corrina and Tanya wrote: “A widely held view is aggression between siblings cannot be abuse.

“But for a surprising number of children, it is.

“This false belief has led to many suffering in silence.”

Aggression between siblings becomes abuse when it is chronic, Tanya and Corrina explained.

It can involve torment through weapons, objects and even sexual assault.

How can sibling aggression and abuse harm your health?

Sibling aggression and abuse can have long-term effects on peoples’ mental and physical health.

But it’s not just the victims that suffer, Corrina and Tanya said.

Both the perpetrators and the victims of sibling aggression can suffer lasting effects to their mental and physical health because of it.

Here are some of the effects:


Siblings who have endured aggression – as well as the siblings behind it – tend to experience higher rates of depression, Corrina and Tanya said.

They also experience issues with:

2. Substance use

3. Delinquency 

4. Sleeplessness

The abuse doesn’t have to be long-term for the effects to be felt.

“Data shows just one incident of victimization at the hands of a sibling is linked to worse mental health in childhood and adolescence,” the researchers wrote.

Sibling aggression can seep into other family ties too, they pointed out, straining parent-child relationships and sometimes causing its victims to become estranged from the rest of their family.

Finally, an aggressive relationship with your sibling can play out in relationships with friends or people you date, Corrina and Tanya said.

How to prevent or intervene in sibling aggression

“Parents often want simply to stop the behaviour and move on – or ignore it,” Corrina and Tanya wrote.

“However, this is a missed opportunity for teaching important social skills.”

If your children or children display aggressive behaviour you should:

immediately interrupt it not take sidesteach them skills to lessen aggression, such as listening, seeing another person’s perspective, managing anger, negotiating and problem-solving

These skills could improve your child’s mental health, they said, and could make them less aggressive in other relationships too.

Clinical psychologist Dr Becky Kennedy shared her own tips on how parents can handle quarrels between their children with The Sun last year.

But when it comes to abuse between siblings, Corrina and Tanya emphasised that “teaching siblings conflict resolution skills is not appropriate”. 

“Engaging in mediation may further victimize the targeted child when there is a power imbalance,” they added.

Parents should immediately seek help from a mental or physical health professional, they said.