There are no yardsticks or scales. Either/or with their wants at the core.
So ethics morality integrity is never in play with them. Which means they have no brakes.
That could explain the how and why of rampant misery inflicted on "the other"
If you never once question that what you do/say is bad wrong evil you just sail through life happily ever after with like-minded ilk around you. SIGH.