https://blogs.psychcentral.com/nlp/2013/12/sibling-rivalry/
“Researchers involved in the study have found that sibling rivalry is often filled with psychological and physical aggression, which can traumatize children, leading to higher instances of depression, anxiety, and anger later in life.
In fact, sibling aggression may be more damaging than bullying.
The study was commissioned by the Centers for Disease Control and Prevention and the Department of Justice Office of Juvenile Justice and Delinquency Prevention.
During the study, researchers found that 32 percent of the children who were surveyed suffered aggressive behavior from siblings that caused them distress and anxiety. According to the lead author of the study, Corinna Jenkins Tucker, this should be treated just as seriously as peer bullying.
According to clinical psychologist Dr. John Caffaro, sibling violence is the most common form of family violence, occurring far more frequently than parental or spousal abuse.
Some studies have estimated that nearly half of all children with siblings have suffered physical violence such as bites, kicks, and punches, while nearly 15 percent of those have been attacked repeatedly.
Even severe incidents are rarely reported because families dismiss them as horseplay.”
How about a broken finger?
How my heart sings 