Circumstances are virtually everything. The events of their births - both Bundy and Keyes left kids, so I don’t feel comfortable getting into the issues of their births. But even Wikipedia discusses it in case of Bundy, as to Keyes, it is almost semi-obvious. And it is specifically about inheritance.
Their rearing. Not only “how bad” their parents were (maybe not). But Lord, if a three year old arranges knives around his aunt at night and no one takes him to a doctor...if he is sadistic towards animals, and no one cares...then the family is bad.
And later, towards being disliked by classmates, acquaintances. You know what is missing in Bundy’s life? Male friends. The same holds true about Gary Ridgeway. Of Keyes...he was in the army. Usually people come back covered in buddies. Keyes was respected, but afraid.
Personality disorders are partially genetic, too. As to antisocial PD, it is almost like a phase of male development. Getting into groups, running away, stealing, joyriding, drinking, using drugs, all nine yards, but doing all these nasties in a group.
Think of it, how would ancient, or medieval, society, deal with these guys? These groups? Well, in Ancient Greece or Rome our teenagers would be young adults, with own responsibilities (mostly, protecting the community). But in medieval times, they’d form groups, the Crusaders, for example...and be shipped overseas, and pillage, fight and kill...and no one at home would see it. And by 30, grow out of it, return back, settle down, get married.
It is interesting that of all personality disorders, antisocial is the one guys may grow out of. Usually, by mid-30-es, via organized sport, army, or AA.
What is different about serial killers? Most are not in a group.
About testosterone, it is hormone like any other. No more, no less. What would “overload of testosterone” do without cellular receptors to it? Without receptors to it, nothing will work. A man would even look a woman
Androgen insensitivity syndrome - Wikipedia
Joan of Arc comes to mind...
And below receptors, there are G-proteins, and yes, it ends up with genes. Today they are discussing “the warrior gene” and MAO, tomorrow, there will be another repas du jour.
