Dubsyd, I understand how worrying b6's behavior is for you. I have a nephew who had a similar destructive phase. It was a long phase from about 2-10 years old. He constantly broke things and could not control his behavior. At one point, when nephew was 8 and dd was 7, I had to watch him constantly because I saw him push dd down several times, and then actually jump on top of her once. He also tore one of dd's dolls apart during that same visit.
He is quite gifted and has also suffered with many physical problems and ADHD. He was really challenging, and because he is my nephew, I worried about him and his future.
The difference is that his parents were also worried. At first, his mother provided very little discipline and would "rationalize" (make excuses for, in my mind) his behavior, saying that he is really bright and likes to take things (like dolls) apart with his hands. I think she also felt like he had to deal with many physical problems so she didn't want to try to work on another problem. Eventually, after problems at school, she got counseling for him AND herself and became able to follow through on discipline as he got older. They have tried many different therapies with him including counseling, medication and even hypnosis. His father was quite frankly worried that he was antisocial and always would be. At his worst, I was afraid that I could never let dd play alone with him. But at 12 and medicated for ADHD, he is much better. He can control his behavior, interact sociably and respectfully, and no longer is the destructive force he used to be.
So I don't know if there's a diagnosis here or not, but I think it would be great if you could tell his parents about what you saw in the context of your concern for him and the possibility that he needs help. If they are already concerned but just haven't talked about it, your desire to support them may feel very welcome.

Last edited by MomC; 12/17/14 06:09 PM. Reason: added b6