You are not a failure. I sincerely hope nothing anyone on WS said has made you feel that way.
I (personally) believe individuals diagnosed as having one of the "dark triad" disorders--Machiavellanism, Narcissistic Personality Disorder, or Anti-Social Personality Disorder--are born that way. BUT, that doesn't necessarily mean their true "nature" is this evil bad seed either. I believe the disorder develops due to a neurological problem in the brain and the root cause of that neurological problem could be many different things--underdevelopment of the brain, head trauma, or encephalitis, for example. While I do believe that triggered events cause the disorder to manifest itself in those who are predisposed, I don't find it helpful for anyone involved to automatically assume that the parents are responsible for it. It could really be anything. A high-stress situation that the child's parents have no control over. Being bullied by other kids at school. It can even be triggered by an illness unrelated to the brain but one that causes the child stress.
I'll give you an example from my personal life. My mother has bipolar disorder. Her mother had bipolar disorder. Logic would seem to follow that I also have bipolar disorder. Let me put it this way: the odds are not in my favor. YET... here I am at the ripe old age of 35 and I've never experienced symptoms of a manic episode, or a depressed episode, or even hypomania. That is not to say that I never will. But, sometimes I wonder if being hypervigilant about my mental health over the years has kept the disorder from developing. I know the importance of seeking intervention... EARLY & OFTEN. I've seen the many ways that choice can make or break someone. If I start having trouble sleeping, I am requesting medicinal help from my doctor. If I start to feel more overwhelemed or stressed out than usual, I schedule more frequent appointments with my doctor and we brainstorm different ways I can reduce my anxiety. I also speak openly about my anxieties and worries and the things that are bothering me much more than my mother or her mother ever did. They liked to suffer in silence. Me... not so much. I honestly believe these proactive measures have saved my life. Literally and figuratively.
Unfortunately, people who are genetically predisposed to certain illnesses aren't always aware of it. In fact, I'd venture to say that awareness is rare. Some illnesses aren't always as clear cut or obvious as bipolar disorder. It may have skipped a generation or two. A predisposition may exist due to trauma or underdevelopment. It is nearly impossible to pinpoint the cause of such disorders because too many factors come into play. Accidents will continue to happen. Defective genes will continue to be passed on to future generations. Bullies will always exist and trauma can always occur. It never does good to place the actions of one on the head of another. No one is to blame but himself. The focus should be on recognizing patterns of behavior that lead to such atrocious acts of violence and figuring out a way to prevent it from ever happening again.
YKWIM?
ETA: I wanted to clarify that I did NOT see the conversation refocus requests before I replied with this ten-page story. I wanted everyone to know that I was not ignoring those requests and just couldn't bring myself to delete it after spending half an hour typing it all out. :shame: