What causes some people to be evil?
It isn't all that hard to accomplish, if you know how to do it. I mean: how to cause some people to be evil. They can't do it by themselves, so if you want evil people you'll have to spend considerable time and effort into making them evil.
In Hell, every novice devil starts at entry level, and they all get the same question on their first night by the fire place:
"What causes the most atrocious burns on a human being?"
"Flames? Hot Irons? Radiation? Acid?"
In other words: "contraria contrariis generantur", or: "Beget the opposing by its opposite". Evil is, after all the art of reversal. Moral reversal in this particular case of causing people to be evil.
This is what you do:
Convince people that by committing atrocities they do good.
By having them believe a series of complete absurdities first. Feed those to them one after the other, and interlace them with perfect logic, so that every step of reasoning between the one absurdity to the next seems to make perfect sense. People are human, which means that when a belief makes sense in step-by-step reasoning, you can be sure that about 90–92% will enter the logical maze at one end, and will come out the other end without remembering where and how they came in.
In other words: they are being made incapable of superimposing the entry thought upon the exit thought, so that they can't come to the realisation that they have come to believe a complete absurdity. All they need to be able to act on that absurdity, is the conviction that it can't be an absurdity, since the logic that binds the morally incompatible elements together in a complete and rounded path of reasoning is so seductively perfect, that they derive their sense of truth from the quality of that reasoning alone, and not from the soundness of the premises on which it is based.
People are suckers for elegant logic and rounded simplicity at the same time. You can enhance their susceptibility by convincing them of the following important foundational absurdity:
"Simplicity is the Measure of Veracity"
Exactly. Don't hammer it into them like a mantra, but be creative: tell them stories that seemingly prove this is true. Presenting it to them raw like this might make them suspicious, as the incompatible elements of "Simplicity" and "Veracity" are too close together. You would risk giving away the game before you have good and well started.
"How long does this process take?"
Until you have effected a stable moral reversal with these people. That is when you have succeeded at getting them "primed", "groomed" or whatever you want to call it.
Theoretically your people are now legitimately evil, since their morals have been completely and diametrically perverted, but they aren't yet culpable, i.e. evil "De Facto", since they haven't done any evil deed yet.
The next step I'm afraid is out of your hands, and beyond their control, as well. Before they can proceed to the business of committing atrocities, they have to get scared of something. Not just scared, but in abject fear for their lives and for their salvation at the same time.
When people get scared to the level of absolute terror like that, they tend to fight whatever is terrifying them, wouldn't you say? Here is where the complete absurdities come in, which we talked about earlier. The main one is the belief that the agents they can physically fight and destroy, are but earthly minions of the actual Agent of Doom, which is however not perceptible, but has near-unlimited powers, omnipresence, eternal life, immanence, transcendence etcetera etcetera ... .
" A bit like God?"
No no not "a bit" and not "like" God. The actual-yet-inperceptible Agent of Doom IS God, but in photonegative mirror image. They already believe in God. It would be foolish to create for these people an Agent of Doom that is too different from God, because that way you have to make them believe in this new entity's existence from scratch so to speak, which you can't possibly do once they are past age ten-eleven or so, because that is when their credulity threshold has become too high for introducing completely new fictional agents that they will take for 100% real. They won't be certain enough of their existence, so that they can't develop a sufficiently pervasive, stable and durable fear and/or hatred.
You can't do before that age either because they can't imagine an evil agent capable of outsmarting God, but that I can assume to be common knowledge needing no further explanation. Experiments have been done with demons imported from other religions, at all ages, but they have all failed.
Your morally reversed people will only act upon perverted faith, provided they are convinced that God may not be able to handle the Imperceptible Agent of Doom, unless they volunteer their most zealous help.
That is when your people become capable of killing and torturing other people in the full conviction that they are doing good, destroying the minions of the Agent of Doom without which this Agent cannot effect their own doom and that of God.
Your people will call their atrocities "acts of faith" (Spanish Inquisition: autos da Fè, and Islamist extremist jihad (ISIL): martyrdom for Islam) because that is what these acts are in their perception.
Summary: you need Holy Good to create Abject Evil. Cold to burn, and heat to freeze. Either a traditional religion old enough to have amassed sufficient authority, or an ideology that isn't necessarily based on the Divine, but that provides enough material for moral reversal among those who already believe in its less virulent form.
I wouldn't say "the Devil's work is never done", but yes I have to admit it takes time and energy, of which fortunately (or unfortunately) Hell has plenty.
I'm a believer of moral relativism. No, I will not answer whether immoral, evil acts are the products of nurture/nature. I don't know the answer.
I believe that every single individual (that includes you and me) has different set of moral value. Usually, normal people's moral value don't differ much with society's moral value (which is, a normal line). Abnormal people's moral value very often defy the normal line. Such people may be evil, may be not.
If the question is changed to be ‘what causes some people to be kind?', I believe the answer would be empathy. Science proves that empathy is the product of both nature and nurture.
If a person has no empathy, does not mean the person is evil. The person is simply unkind, but not evil.
Humans long time history has proven that the most compassionate people are capable of evil wrongdoings (I'm looking at you, religious-ridden terrorists!), and vice versa. Humans aren't at all unipolar.
Different moral value itself is enough to be doing evil things. What causes the different moral value usually is cognition, but maybe there are something else.
"Evil" is itself subjective; you're getting into murky territory, here.
Very few people are evil to themselves. Those few who are, are mentally disturbed. There is no profit or gain in being truly evil, and great risk.
That being said, many people are blind to the evil they do, especially in the name of good.
I think Hanlon said it best; though I doubt he was the first. "Never attribute to malice that which is adequately explained by stupidity." People are dumb a lot more than they are evil.
Thanks for the A2A; hope this helps!
That is a difficult question to answer. There are theories about an extra male chromosome or neuronal hardwiring gone wrong. Some say it's nature, some say nuture. I don't believe in the devil. The truth is no one really knows. I think it's a bit of both. I mean, one person's trauma is another's walk in the park. There is a fine line between genius and insanity. Some people suffer brain damage in utero that is so slight as to go unnoticed. Maybe someday we'll know and be able to stop trouble before it starts. For now there is no answer. Be well.