I think it's a matter of social conditioning, though, not an intrinsic part of most of the people who behave this way (though this antisocial behavior leaves a lot of room for psychopaths to operate). "one must pay their debts" is ingrained in us as a truism from birth. I suspect many have never even considered the possibility that loaning money itself was considered a despicable act in many societies, or that it's possible to relate to other human beings in a way that's not transactional. this fact gives me hope that we can recondition most of these people - we must at least separate them from society and try. if they're truly irredeemable, throw them in the volcano. but we must hold out hope for the possibility of human growth and change.