@valiantt:
That's an over-generalization. Psychopathic intent is a wildcard when it comes to speculation. Sure there might be this lust, power, thing going on, but what about those suicide bombers with "righteous intent"? (Not going to mention any names here). They have an idea that they are doing something hazardous to others for the sake of utilitarian purposes (I'm bettering the world, I'm doing this to help others, etc…). Where does that place them?
Wrath/Anger, I'd say. Because, they are killing people that don't conform to their beliefs out of anger for not conforming to their beliefs, if that makes any sort of sense; they are bringing down the 'wrath of what they believe in', so to speak. Can't explain it 100% without naming names, basically.
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@Wagomu:
But you see, you're just forcing that fit at best. Psychopaths don't need a reason to aggress.
The seven deadly sins views sin through the scope of intention. Not all evil results from bad intent, though. Psychopathy is neutral intention. There is also a non-negligiable amount of criminals who act with good intentions.
I'm not forcing anything, it's a basic psychology (I study psychology…kinda-sorta). Almost every single psychopath commits their crimes for a reason, it's simple as that. And, 9 times out of 10, it's because they lust for power and control over others (this can be attributed to a rough upbringing, with them being dominated and controlled over by an elder). Or, they find sexual arousal through the suffering of others--a reason some psychopaths keep 'trinkets' from their victims, so that it's easier to remember the pain they inflicted so they can 'turn themselves on' whenever they want to.