The evil genius doesn't start out evil - they become that way over time.
Anyone with a few active brain cells today, and that is astonishingly not changed since the dawn of time, is automatically "other than" the others in the village, and probably doesn't "play well with the other kids".
This brings all manner of societal retribution, and it matters not if you live in a hut in the rainforest, or in a penthouse in Manhattan; if you are different enough in the way you think to be classed as a genius, you won't fit in and you're basically going to get a whole lot of shit, or negativity if you will, thrown at you from an early age.
Some of that is pure rejection of otherness or xenophobia; some of it is jealousy and envy, if special talents are being displayed. Some of it is stupid, thoughtless cruelty, the domain of the particularly mentally challenged, and some of it is deliberate cruelty and downright nastiness. Parents and other authority figures might be dismayed, ashamed, disgusted and resentful of their "peculiar offspring" and most of all, there is general and TOTAL lack of rapport with the young genius.
That plays out in absolutely mishandling them, misunderstanding their needs, misunderstanding their communications and so a lot of wounds are inflicted on a youngster who is already having trouble trying to make sense of a world where so little actually makes any sense whatsoever, and to whom adults and elders are not acceptable role models.
You could say that such people grow up in an ongoing nightmare and there seems to be no way out.
The genius child trying to grow up in this mess, and trying to hold it together somehow enough to not go mad altogether, has few options.
If they can, often children with genius potential will play it down as much as possible so they can blend in enough to avoid the endless punishment of rejection and gain some form of positive energy from other humans around them - love, friendship and so forth.
But with extremely intelligent and visionary children, this is not really a possibility; and if they make it through to adulthood at all, they will carry the scars from the battles of their childhood, and that is where the evil genius was truly made.
- OF COURSE such people are seething with resentment, anger, RAGE at the entire human race on all manner of levels - at the personal level, because they were let down by their immediate family; at the societal level at being rejected by others in the society and not appreciated; and at the global level, by simply contemplating the horrors of humanity's stupid actions overall at any length of time.
Depending how bad it was, and in a simple cause-and-effect fashion, our evil genius will get their payback.
And if there was never anyone who loved them properly, and there wasn't "a single one amongst you" who was true and good, and treated them right, then the logical conclusion must be to destroy all of humankind, the ultimate evil genius revenge.
It's really very simple when you think about it.
"Ordinary people", the good burgers, should learn to understand how dangerous it is to treat genius children badly.
One single such child can change the world, quite literally and practically, for millions, even for billions of "ordinary people" when they grow up to become an evil genius.
The ordinary people see then their villages burn, and their schools shot to pieces, and ask all wide eyes, "But how did that happen?!"
It's happened enough, and for long enough now, for folk to start paying more attention. That strange creature in your classroom, on your schoolbus, in the back row of - well everything; the one that everyone likes to torture and have fun excluding, and making suffer, day in, day out, has the potential to become the equivalent of a human nuclear bomb that takes out all your works, your children, your grandchildren, and all and any hope for the future there ever was.
And in a way, there some kind of poetic justice about this whole process.
If you want good geniuses who will bring us the next Renaissance of humanity, instead of evil geniuses who try to blow up the whole world and everybody in it, stop practicing the religions of sameness and conformity.
Love all children right, not just your own; and pay attention to when the "strange ones" are being tortured and mistreated AGAIN, and step in and hold up your hand, say, "That is ENOUGH!"
In doing so, you might have just saved your own life, and that of all of humanity by being that one example that the evil genius remembers as they are about to push that big red button to end us all for good.