The study looked at more than 3,500 kids under 17 with at least one sibling. Researchers found that 32 percent of children have experienced at least one form of aggression from a sibling.
ABC News Chief Medical Correspondent Dr. Richard Besser has this advice for parents. "You need to take it seriously and there are some things you can do at home. You want to have a rule. You're just not going to accept this. There's a zero-tolerance for bullying," he says.
Besser adds that parents should set a good example and when parents do see bullying, they should separate the children. He also says parents should always try to acknowledge the positive interaction between siblings.
The study is published in the journal "Pediatrics."