It found that bullying by brothers and sisters has the same harmful effect as it does from schoolmates or strangers.
Interestingly, they found that even mild bullying — a punch once in a while — could be detrimental.
And young children suffer most.
Researchers at the University of New Hampshire conducted more than 3,500 telephone interviews with children and teenagers (an adult caregiver was interviewed if the child was younger than 10).
The researchers asked these kids whether they had experienced physical assault, property damage or "psychological aggression" — in other words, name calling, meanness and ostracism.
Kids and teens on the receiving end of sibling bullying did, indeed, experience mental distress from teasing and aggression.
ABC Chief Medical Editor Dr. Richard Besser says he asks his young patients about being bullied at school, but doesn't ask about bullying at home.
However, he will now, and he jokingly said he is looking at his childhood experiences in a new light.
Here's the exchange between Dr. Besser and Good Morning America co-host Robvin Roberts.
Roberts: "How was it in your house? Because i've met your brothers."
Dr. Besser: "I was picked on all the time. I was the youngest of 4 brothers."
Roberts: "But you didn't think of it as bullying at the time?"
Dr. Besser: "No, it was just what kids do."
And he went on with a big smile, "I'm gonna give them (his brothers) a call when we're done."