Lead author Corinna Jenkins Tucker of the University of New Hampshire said fights between siblings -- from toy-snatching to being banished from the bedroom -- are so common they're often dismissed as a part of growing up, but sibling aggression is associated with significantly worse mental health.
"An implication of our work is that parents, pediatricians and the public should treat sibling aggression as potentially harmful and something not to be dismissed as normal, minor, or even beneficial," the researchers wrote.
Tucker and her colleagues analyzed data from the National Survey of Children's Exposure to Violence, a national sample of 3,599 children, ages 1 month through 17.
The study looked at the effects of physical assault with and without a weapon or injury, stealing, breaking a possession, and psychological aggression such as saying things that made a sibling feel bad, scared, or not wanted.
The study, scheduled to be published in the July issue of Pediatrics, found of the 32 percent of children who reported experiencing one type of sibling victimization in the past year, mental health distress was greater for children age 9 and younger than for adolescents ages 10-17, who experienced mild sibling physical assault, but children and adolescents were similarly affected by other psychological or property aggression from siblings.