Unfortunately it’s very often poor parenting at the root of the problem.
I am really thinking of the extreme cases like those I mentioned,rather than merely children pushing the limit, and I really do not think that upbringing comes into it. many children like this are mentally ill or mentally abnormal in some way and the parents see themselves as failure for having a child like this (of course many are adult children), many parents struggle to admit just how 'deranged' their child is and struggle to admit it too themselves, this is becoming clear in the Southport enquiry and the elder abuse case I was involved with. there is that unexpressed beleif that there can be a solution, something minor, that does not require anyone to do anything very much, certainly not involving in authorities in any way.
Thank goodness. I have never faced anything like this, but I do wonder whether if things were as bad as these cases, I would not at some point step back and tell my child, thats that, you are to get out of the house and, almost, my life and I would turn to the authorities and say. I have done what I can, you take over.