You make an interesting point, yet I do not agree. Obviously, the greater social/cultural influence on the ability of a people to creatively and critically think is huge, but you are severely underestimating the subtle intellectual effects of early and constant linear-logic-based teaching.

If you read the writings of the original founders of the prussian education system -- the tenets, goals, and purposes of it-- it is hard dismiss the impact it has on children's minds from early on... This image is about the education system's overall process of "squaring the circle"- foundationally setting the mental faculties of children to conform and not question, and to accept adjustment from authority rather than being an agent of socio-economic change. So to your point, yes, the overall social impact is great, but it rests upon the continuous schooling efforts...

The following quote is from John Taylor Gatto, referring to the work of Alexander Inglis, the author of Principles of Secondary Education and was very influential in instituting the Prussian model in the US. In his book, Inglis established 7 principals for what would become our prussian-based education system.

According to Inglis, the first function of schooling is adjustive, establishing fixed habits of reaction to authority. This prepares the young to accept whatever management dictates when they are grown. Second is the diagnostic function. School determines each student’s "proper" social role, logging it mathematically on cumulative records to justify the next function, sorting . Individuals are to be trained only so far as their likely destination in the social machine, not one step beyond. Conformity is the fourth function. Kids are to be made alike, not from any passion for egalitarianism, but so future behavior will be predictable, in service to market and political research. Next is the hygienic function. This has nothing to do with individual health, only the health of the "race." This is polite code for saying that school should accelerate Darwinian natural selection by tagging the unfit so clearly they drop from the reproduction sweepstakes. And last is the propaedutic function, a fancy word meaning that a small fraction of kids will slowly be trained to take over management of the system, guardians of a population deliberately dumbed down and rendered childlike in order that government and economic life can be managed with a minimum of hassle. And there you have the formula: adjustment, diagnosis, sorting, conformity, racial hygiene, and continuity.

Also, I agree that lack of attention and apathy are a major cause of the conformity-thinking, as a mentoring relationship with an intellectually honest teacher is going to empower students, holistically. So within the large class, children are structurally set up to be intellectual failures where we can be more easily influenced and manipulated by the greater social/cultural faculties, as you mentioned in your comment.