It seems to be the accepted norm that siblings will fight and torment each other. But researchers say sibling bullying should be treated as seriously as bullying from a peer. In fact, being picked on by a brother or sister can be harmful to a child's mental health, found a study published online today in Pediatrics.

More than 3,500 children and teens aged 1 month to 17 years or their parents were interviewed for the study about various levels of aggression shown by siblings and peers as part of the National Survey of Children's Exposure to Violence.

They looked at the range and extent of sibling aggression experienced by the children, including instances of physical assault with and without a weapon or injury; stealing something with or without force, or breaking siblings' things on purpose; and saying things to make the child feel bad, scared or not wanted around.

The results showed that mild and severe sibling aggression in the past year was associated with significantly worse mental health for both children and adolescents. They assessed for mental distress by asking questions relating to depression, anxiety, and anger. When comparing sibling versus peer aggression, each type of bullying predicted greater mental distress.

We asked study author Corinna Jenkins Tucker, Ph.D., C.F.L.E., an associate professor of family studies and Carsey Institute Faculty Fellow at the University of New Hampshire, to tell us more about the findings.

Why do you think bullying by siblings often is dismissed as normal, benign and seen as beneficial?

Generally, there has been a historical acceptance of sibling aggression reflecting the belief that it is normal and benign. For some, there is a belief that it is beneficial for learning to manage conflict in other relationships.

There are different norms of acceptability with regard to aggression with siblings versus with peers. Peer aggression is less likely to be accepted than is sibling aggression.

Is it a problem for parents to believe "some fighting in normal"?

Siblings will fight with each other. However, there are constructive and destructive ways of fighting. For the types of victimization that we assessed - mild and severe physical assault, property and psychological aggression- being the victim of each type was linked to greater mental distress in children and adolescents.

How does severity and frequency play a role in the bullying? How does bullying play out differently for children and teen siblings?

Our data showed that both mild and severe forms of sibling victimization were linked with greater mental distress in children and adolescents. In one case, mental distress was greater for children than for adolescents with regard to mild physical assault (assault without a weapon or object and without injury).

We also showed that experiencing just one type of sibling aggression in the past year was related to lower mental health for children and adolescents compared to those who experienced no sibling aggression.

How are sibling and peer bullying similar and different?

We were able to show that being the victim of sibling and peer aggression generally was associated with lower mental health. In one case, however, being a victim of peer but not sibling property aggression (forcibly taking things away, breaking things on purpose or stealing things) was associated with greater mental distress.

What is the significance in determining kids who have experienced sibling and peer bullying had greater levels of distress that a child who had experienced one type of bullying?

In our study, children and adolescents who experienced poly-victimization with regard to physical aggression had the worst mental health. Poly-victimization is obviously a possibility and something parents and others should be aware of.

One limitation of the study was that it could not determine the direction of effects between aggression and mental health. Could you tell us more what this means? 

Our data were collected by an interview conducted at one point in time and we are not able to establish a causal relationship between sibling victimization and mental health. We are able to say that our data show a relationship or an association between being a victim of sibling aggression and mental health. Thus, it is possible that being a victim of sibling aggression caused lower mental health or that lower mental health caused someone to be a victim of sibling aggression.

Our analyses, however, did show that even after accounting for other kinds of co-occurring victimizations such as maltreatment by parents and internet victimization that may explain what we found, the relationship between sibling aggression victimization and mental health remained.

Should parents talk to their kids about sibling bullying?

Parents can help their children and adolescents learn to fight constructively and develop effective conflict resolution skills. Parents can assist children with identifying the issue or problem, seeing each other's point of view, and working towards a mutually agreed upon solution. Once children learn these relationship skills and as they get older, give them opportunities to use them independently with each other and their friends.

Our work suggests that prevention and intervention programs to stop aggression and parenting programs include a focus on sibling aggression. The difference in norms of acceptability of sibling versus peer aggression should be reconsidered.

Other Resources

For more information on bullying, when to seek help for a child who is being bullied or bullying, and common signs of a child who is being bullied:

KidsHealth: Teaching kids not to bully

KidsHealth: Helping kids deal with bullies

National Institutes of Health: Bullying

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