We have 8 and 11 year old boys. They generally get along and people remark how well behaved and mature they are. The 11 year old, unfortunately, can be a bit clueless sometimes, and causes the 8 year old grief... For example, he might pick up the 8 year old's toy and fiddle with it, only to break it in seconds. But, more often than not they're best friends. The 8 year old can get very upset/frustrated with the older one when he's clueless, though. Just recently, the 11 year old broke a key prop for the 8 year old's Halloween costume, just about an hour before the party they were to go to. Feeling so bad for the 8 year old, I called around and then rushed out to find a replacement while the family was having supper.
When I got back, I heard this story: The two boys had reconciled and the 8 year old was calmly talking with the 11 year old about costumes, and, while at the top of the stairs the 8 year old said "I have an idea for you..." and pushed him down the stairs quite deliberately. Fortunately, the 11 year old landed well, but it could've been... my stomach is in knots thinking what it could've been. After it happened, allegedly the 11 year old shouted "what was that?!" and the 8 year old kept repeating "I'm sorry I'm sorry..." I asked him to explain why he did it, what he was thinking and he's at a loss, just saying "I don't know."
It wasn't heat-of-the-moment, though obviously there was history. It seems almost sadistic. Should I be worried about the 8 year old's mental health, here? Our "punishments" are usually natural and logical consequences, but I'm at a loss here.