The professor in Why You Are Who You Are: Investigations into Human Personality cites research that personality is highly heritable and disordered personality characteristics are even more heritable.
The Son Also Rises finds that personal success is highly correlated with extended family success.
The perpetrator of the recent Thousand Oaks shooting was plainly someone with a disordered personality and also not a very successful person. The media seems to blame his actions on PTSD from his time in the U.S. Marine Corps. Certainly a high percentage of Americans who serve in the modern military become disabled due to PTSD, but is that enough to explain a shooting rampage?
I’m wondering about this guy’s family background. Were his biological parents, aunts, and uncles simply mild-mannered accountants? Does he have siblings? What are they like?
Readers: What have you heard? Would someone who looked at this guy’s relatives have had any inkling that he was likely to do something crazy and violent?
Related:
“Long was close to his mother. Court records show his parents divorced in 1991 when Long was a year old.” https://taskandpurpose.com/ian-david-long-thousand-oaks-shooting/
Raised by a single mom.
Like the Norwegian shooter, ABB, also raised by a single, mom, in his case, the father, who didn’t have the defects the mother had, was still denied parental rights.
https://www.telegraph.co.uk/news/worldnews/europe/norway/9592433/Anders-Behring-Breiviks-mother-sexualised-him-when-he-was-four.html
Things may not have been all that well with him before he went into the marines:
https://losangeles.cbslocal.com/2018/11/08/thousand-oaks-gunman-high-school-coach-assault/
Phil, the man was at one point a Marine(ie a highly trained killer). At one point he was married. At the time of his killing, he was living with his mom and likely handing all of his cash over to his ex wife. We have deliberately put many men through this exact sequence. A better question might be what if we had to explain to Socrates, Plato and Aristotle that we expect this to go well?
Robert Plomin, a major researcher in this field, just published Blueprint, available in Kindle format. Check it out. Everything is at least partly genetic. It turns out that even environment can be genetic, which could mean that people apt to join the military, on average, could be more prone to psychopathologies.