Often times, what are seen as outright cruelty comes from individuals who believe they are on a just mission, and the extremes are justified.  There is a belief you need to send a message to people, and intimidate and bully, to get what you want.  You believe you are entitled to certain things, and people unjustly have them.  There is also a push to pay back those who believe wronged you or your group.  Part of this is a group mentality also, where you believe your group was wronged.  End result, you do horrible things in the name of what is right.

I'd say it all stems from blacks and jews.

Oh I know it still goes on today....

A couple of months ago, on the BBC World Service, they were interviewing a lady from an African country, I forget which one, it might have been Republic of Congo.  But anyway, she survived an ordeal where some thugs beat her up, and cut off one of her feet, threw her foot in the fire, and told one of her kids to eat her dismembered foot, and when her child refused, they killed that child.  I don't even know how a person would even think of doing something like that.....

The whole nature is cruel, if you think about. Cruelty is not a human monopoly. If you take a deeper look at animal life you will see that there is slavery, prostitution, rape, incest, murder, war, cannibalism, etc. It was there before the humanity formed the first civilizations. So cruelty is nothing that was invented by humans. We were just not able to get rid of it completely by now.

It is also worth noting that civilization is nothing that you acquire by birth. It is something every individual has to earn through education. One of the overriding principles in Nature is that the strongest will survive and the weak has to die. And that is a principle that modern human civilization has overcome. There is some Altruism found in Humanity. You can see acts of violence, terrorism, war... but you will also see acts of kindness, sacrifice and love.

You're right, maybe because those were more recent events....

In terms of power, maybe selfishness is a better description??

Also, when you say "push the other parties into an inferior level, to dehumanize them"--that seems a bit like a contradiction.  To "dehumanize"-- does that mean it is "human" to be cruel to others and to subjugate them?  I mean, is it "human" to "dehumanize"?

Power, Greed, Insanity, Revenge, and all of that in your subconscious as well.

Evolutionary built-in overpopulation control?

hmmmm.....

overpopulation control?

I never thought of that...

Nature's way of population control??

I suppose....

But why would it have to be sooooo nasty and cruel?