Were kids always this mean?

When I was in school the kids were ridiculously mean to each other. I think it is beyond "kids just being kids", I really just think maybe a 25% of the kids were just soulless psychopaths. They just did not care about how other kids felt. For example they would point out some physical flaw that another kid had, make fun of them for it, laugh at them. And when they made the victim kid cry, this would make the bully kid laugh harder. They would have a great old time psychologically traumatizing other kids.

I wonder if kids were always like this. Is this kind of bullying just a natural part of growing up? Or are a certain percentage of kids really just demonic scum who would be better off dead?

I've posted this before but here is an example of what I am talking about:

https://youtu.be/l93wAqnPQwk

Have you read Lord of the Flies?

I just read the summary on Wikipedia. Basically the summary is "it's not just kids but adults too". I guess children's cruelty is more obvious, but as they grow they learn to inflict their cruelty in subtler ways.

It's not about adults, just children.  The point is that humans are a rather nasty species and are only civilized through a proper upbringing.  So basically most children are beasts who are gradually trained to behave in good cultures.

In dense, civilized, urbanized societies, being an immoral, nasty beast aids survival, since fellow humans are the usual obstacles.

In pre-civilized, sparse hunter-gatherer groups, being moral is key to survival, because the main obstacle is nature itself.

In today's overpopulated era, the former, faster breeding species greatly outnumber the latter kind (r-selection vs. K-selection).