It makes sense to isolate together those who can. The special schools don't do anything special, they just cut down the distractions, shift 0.5-2 university years into the school and spice things up with some competitive math/physics/programming/chemistry/biology/geography/etc.
> the socioeconomical situation is exactly the same (because communism)
Not true at all. It might look that way to an american, but there are things like social capital, and it's not even true for financial capital. From USA perspective we were all equally poor, but from our perspective and "in our world", 300 vs 900 usd monthly wage is (was) a huuuuuge difference.
You have to consider that my parents and parents of my former classmates were raised during actual communism. Do you know how they raised children during communism? They beat them, because disobedience could mean death or lifelong prison or being sent to uranium mines - for the whole family. One bad word was all it took. And many parents haven't yet realized, even today's, that this is not the correct way. On top of that, during the 90's, rampant corruption has emerged, then the economical crisis, etc.
And then of course the teachers - their role during communism was different that what it should really be today, and many have not realized yet.
About the beatings: it's more about the Russian culture, it's even kinda normal for the husband-wife relationships in some regions. To the West there was less of it.
Sounds like something from a school history textbook. It was way more complicated than that; the "ruling minority" or proximity to it was nearly irrelevant to most people (and also a direct threat - you stayed away from these people and their 'friends' as much as you could), what mattered more was your street's communist committee, the teachers at schools, if you wanted to have nicer (or any at all) stuff, then you had to know the shopkeepers, if you wanted your child to go to a high school, you had to know the principal, if you wanted your child to go to university, then the whole family had to have a clean and pro-communist record, if you wanted to visit a doctor, you had to know them or bring something (not necessarily money - money was not that useful), if you wanted to have a okay-ish workplace then... (I could go on forever)
In my previous comments, I was talking mainly about the 90's and early 00's - post-communism. I'm also not a Russian, I'm as west as communism got.
For the positions like for example even drivers for the high party members it starts getting unequal.
And about the nineties: inequality in the nineties is weird because very large amount of the criminals who got rich didn't bother to educate their children. Of course, some part of them opted for expensive teachers/schools or for sending children to the Western schools, but the "getting by force" attitude of the parents didn't really mesh well with learning.
Of course there are countries that had it even worse, like Hungary and Romania, and the states that broke off the Soviet Union.
In the 80s and 90s some attempts were made to try to escape this reality by changing the question. Multiple-factor intelligence models were proposed and widely accepted by pop-psychology, but most academics acknowledge now that there is some general intelligence level, a "g-factor".
Anecdotal - I always remember my aunt who was a literature teacher. She always stuck to those ideas and told me that it's obvious that there are different types of talents, because there are people that are good at maths, but do a lousy job in her classes. What she did acknowledge once though, was that people that were good at maths were also the ones that have been writing the best essays from all of her students. There was something that underpined their skills in both areas, but since they knew that they can achive something real in maths they probably did not try so hard to "pick the right key" in interpretive literature tasks. On the other hand for those students that were a bit slower literature was the only field that thay could perform well. Good literature students did not have any particular field in maths that they could perform well in. They stuck to literature, because they could memorize all the important answers and boast that they poses some innate talent.
Anecdotal 2 - Sure, there are some kids that could perform in one area better than in the other, but in my experience this variance is overshadowed by the difference between kids that can do ALL things well and kids that can do NO things well.
EDIT: A nice example of the multi-factor intelligence "scam" are the books from D. Goleman in "Emotional Intelligence" series. They were mostly targeted for middle management people and were very in line with the whole trend. The main motive is that emotional intelligence is a much bigger factor than general intelligence in the context of career progression and overall success in life. What was not made obvious is that the comparisons were done in environments of people that were already successful. If you take a group of people that have a high iq level, then it's very possible that the most successful will be the ones that can work with people a little better. Unfortunately it's not sufficient to be a peoples person to achieve high efficiency in such environments. The "hidden" conclusion was: GI + EI > GI; EI < GI; GI + GI < GI + EI (at least to some degree). There were also some unresolved questions - can you really possess EI without a sufficient level of GI? Isn't EI just a form of GI? In summary there was a lot more of nitpicking of definitions than actual science. It all felt like p-value hacking on language level.