My personal theory is that it's a combination of a superior, universally-available education system;
But what would cause a "universally available" system to have a high standard of quality. Even today, private education is of generally higher quality than public education--and there has yet to be a demonstration of
lower quality in private education.
This is because of the principle of
competition in the market: the provision of the highest possible product at the lowest possible price, for the sake of gaining the greatest possible demand, in order to make as much money as possible. Public education has no such element of competition: its funds are guaranteed, regardless of quality.
the lack of the negative effects of poverty on childhood mental development stemming from the final abolition of poverty and economic classism;
Which means...what, exactly? Socialism? Communism? If not, what is meant by "abolition of economic classism"? How is this brought about?
Remember, economic classism is
not neccesarily a bad thing.
Poverty is a bad thing. But, indeed, a high standard of living results in a steady decrease in the negative effects of being at the bottom of the ladder. And a ladder is for the purpose of
climbing. Take away the ladder--make everthing come to the people
without the need to rise on one's own effort--and you
hurt society, rather than help it, because you create
dependency.
the presence of a highly-effective, universally accessible mental health system;
The problem with this is basically the same problem with "universally active" education, as stated above. If this universally acessable medical system is government-provided, quality and efficiency lessens, because of the guarantee of funds and provisions. A
market-based health system results, again, in competition for the provision of the highest possible quality at the lowest possible price.
and the final triumph of liberal democracy and leftist political value systems.
If by "liberal democracy", you mean what we discussed in another thread--namely, a "free society" which emphasizes individual rights--than yes, that results in the betterment of society.
But what is meant by "leftist political value systems"? I hesitate at this, because that may not be neccesarily a good thing.