Suppose biology rules behavior a lot more than we care to admit. In a more unrestricted state of nature, groups rapidly cull this type of behavior constantly, keeping it rare and unknown to the species.
Abandon that process, begin to eliminate the selective effects which eliminated that antisocial nature anytime it arose, and it is only common sense all sorts of unusual behaviors will begin to rear their ugly heads.
I’d bet, go back through this kid’s family tree, and you’ll find relatives who would have quietly disappeared centuries ago, and nobody from their group/town/family would have cared to punish the disappearers, and they probably would have patted them on the back had the disappearing come to light. Of course in that scheme, this kid would never have been born, because these genes would have been removed before they became a real problem.
The most amazing thing is how lack of what we call civiization evolved man by force into a kindly and civilized creature, while the too tight embrace of civility devolves man right back into a cruel beast.
Not sure there is any answer to the issue there. Just an observation.
It’s ironic that here in the 21st century we now have public schools and medical confidentiality laws to help ensure that the kind of people we herded onto Indian reservations 150 years ago will mingle with normal, decent human beings without any constraints at all.