Thanks for sharing your point, very interesting. I believe you when you say your brother was not abused, but are you sure he received all the love and care he needed? His needs might differ from the norm, especially if he has a neurodiversity such a sociopathy - if his specific needs were not fulfilled, it can cause behavioural issues.

For example, many children need to be hugged, but some hate that - so a parent might hug all their children, but for the child that hates hugs, their needs are not getting fulfilled (but the parent thinks "Im doing a great job, I don't abuse my children, I hug them every day..." etc). Each child needs love and care specific to them - so in the case of your neurodiverse brother, his needs were likely not of the norm and perhaps more specialist. The absence of abuse is not the full picture.