As with peer bullying, sibling bullying is also harmful to a child or teenager's mental health, the new research finds.
"Historically, sibling aggression has been unrecognized, or often minimized or dismissed, and in some cases people believe it's benign or even good for learning about conflict in other relationships," says Corinna Jenkins Tucker, lead author of the paper and an associate professor of family studies at the University of New Hampshire.
"That's generally not the case in peer relationships. There appears to be different norms for what is accepted. What is acceptable between siblings is generally not acceptable between peers."
The mental health consequences of bullying between siblings are real, researchers say. Tucker's report used data from The National Survey of Children's Exposure to Violence, a phone survey that collected the experiences of 3,599 children aged 1 month to 17 years who had at least one sibling younger than 18 living in the household at the time of the interview. One child was randomly selected to be the subject of three telephone interviews.
Children ages 10 to 17 answered the questions themselves; for children younger than 10, the parents answered the questions. (Tucker acknowledges this is a potential limitation of the study, as parents may not know as much about sibling conflicts as they might think -- particularly if the children share a bedroom.)
The interviewers asked about incidences of sibling aggression in the past year, and they also assessed mental health by asking how often the children experienced anger, depression and anxiety.
Of the children interviewed (or interviewed by proxy), 32 percent reported experiencing at least one type of sibling victimization in the past year. Researchers found that "all types of sibling aggression, both mild and severe, were associated with significantly higher distress symptom scores for both children and adolescents," the study authors write.
Image: Siblings fighting, via Shutterstock