Oh, that's my own term that I've somehow deluded myself into thinking was more common. A "studentry" (not referring to a school's student body) is more of a dystopian thing, where you're taken from birth and raised by teachers. Because schooling can only go so far when you still have to go back to your parents who will always try to infuse into you their own beliefs and ways (plus, they get four to five years to do so, those years being the absolute most important in any person's development).
It's been proven that you can turn any "average" person into a prodigy if you raise them in the correct manner, and your ability to learn languages also forms most quickly between ages 0 and 5. So if you are willing to go full totalitarian, the best way to get a high intellect population is to take newborns and put them into these studentries and then begin teaching them from the moment they arrive. Because they do learn even at this stage. They learn things in the womb, but it's when they're born that it kicks into high gear.
Naturally, you can see how that might be troublesome because you can effectively mold a whole generation's entire reality if you can raise them from birth. Indoctrination at schools or from entertainment or from church is scattershot and tends to focus on when a child can actually understand these things. But a studentry is infinitely more focused. The only reason why we don't have studentries in real life is because they're technically impossible to pull off. One, the outcry you'd get from mothers would be legendary. Two, you're still raising them with other humans. We'd need machines to make them effective. You'd also need machines to keep the anguished mothers in their place.