Well it's only a month later...
It isn't an answer, but I think it helps refine the question to keep thinking the horrible - that there are many subtle ways to initiate a process that's a few parts enslavement, a few parts domestication, and something else I don't have a term to describe that captures the inevitable rise of something before it 's fully realized.
Agriculture does that, but it is nightmarish to think of it being done to kids, yet that's what I'm saying.
The school "system", the weird sexual prohibitions that essentially harness the growth toward sexual maturity of children.
Even something as contentless as money. By making a particular system or thing or whatever something you have to do, or participate in, the beneficiaries of that system prosper.
Another way to run the same scam is to establish the parasitic hook in a place the victims will inevitably be.
Skewing the recognition of the seasons, off the solstice and equinox, and on to the arbitrary calendar does that perfectly.
We all live through the year, we all participate in the social framework, and we all use the tools we find as we need them. Dates and events that are institutionalized as permanent fixtures, and virtually brainwashed into our heads through the school...

It's horrifying I think because it means we're sharing space with a superior creature that isn't human. I know that's science fictiony but it's pretty accurate too.
Superior in the way a farmer is superior to his animals and crops.
And just like the evolution of the domestic animal eventually produces domesticated creatures who need it, who can't live outside the farmer's safe perimeter, well look around.
Not superior morally. Morality has nothing to do with it. Unless we insist that it does.
But that means we have to get ahold of "we", and what that "we" means to "us".
 

The best place to hunt
Poachers.

All my life I was told Humans evolved from Animals. Yet today I am more certain than ever that nothing new can evolve from Animals. Thus Humans are just Animals, it's all they ever were, it's all they ever be. Perhaps the difference is that we don't go to the well, or the river to drink where a predator might wait to hunt us down. We open glossy magazines and turn on TV. This is how we drink. And there is where we get killed.

I think Humans will always hunt Humans. The predator in us does not live to create abundance. We thrive on scarcity. Our biggest achievements are when we face scarcity and overcome it. We've not evolved to be Animals of abundance. We continue our scarcity and if we don't find it we manufacture it. This is the only way we know how to hunt. A pity.
 

I've tried all over the place a bunch of times to get down what I think is a crucial misconception about what we are, as an evolving thing, that we're taught and trained to miss entirely. That the very concept of evolution is so threatening to - knowing that what we are is changing all the time. That the face of humanity is altering to its environment and that that environment is/was being bent to serve something that isn't central to what we were for most of our time here.
So why are we told over and over that what a "human" is is what a "human" always was?
So that we don't start wondering about what's happening.
About how easy it would be to sort out the wilder strains from the gene path.
How the big institutions not only seek to preserve themselves but also to preserve the process of selection amongst the membership they carry.
That "human" is most accurately a description of whoever's around. The scary part of that that nobody seems to get is that in a few quick generations whole branches of the human presence can be cut away, and the ahistorical young will never even know they were there.
That's been happening all along.
So that what "human" was 15,000 years ago is not what "human" is today. We adapt to the environment like any good generalist organism. Look at the environment, look at the people that rise to the top.
The center of what we are shifts as the population changes.
Like the freeform bands of hippie times - Who's in the band? Whoever's on stage.
Yet there is something there that's been there all along. But as you say it was there when we were animals. And before that.
The predator/prey thing evolves into rancher/stock, or even farmer/crop, and cannibalism in its most basic b.b.q. form evolves into the owning of other lives, or even more effectively, a version of the domestication thing where the animal is no longer capable of free living.
Survival being paramount, and held solely in the master's hand.
The rationale behind primate research is only a whisper compared to the larger command.
Willing and active participants make the absolute bestest slaves.
There are intelligences that recognize this and have no loyalty at all to what's being domesticated. Morlock and Eloi. Species split takes hundreds of generations and is no more recognizable in the moment than the hour hand of a clock. We were once something that the chimpanzee was also at the same time. Now we aren't.
And there we are.