The hard-core, months-long, daily prep courses for super-high-achievers seem like extreme overkill. The kids who need that are probably the ones in the 700-900 range, who need to learn a baseline level of math and English for the first time (of course, if that were possible, it would have already happened in school).
There is a commonly held belief that "Asian students do better because their parents push them really hard".
The parent comment is arguing that the "really hard" part is not necessary. They are stating that if you condition on "studied at all" (above some minimum threshold) you'll explain away most of the group variance.
They're also not even arguing against the claim that studying more is better, just that the biggest improvement is in studying at all.
The final conclusion is spelled out clearly: If you want to improve test scores across the board you don't have to "push kids really hard", rather you have to work to get all students to get over the initial hurdle of studying some minimum threshold.
Now the parent might not be correct, but it's hard to see how you're even coming across with the reading of that comment you are.
Looking at the math section, you might get a 600 if you don’t study but could know all the material but don’t know how to take the test.
But to get a 600 requires you to know a certain amount of material and know how to take the test. Most kids at my HS couldn’t get a 600 math even with 40 hours of math prep.
Test prep has diminishing marginal returns.
On the flip side that means just 1 hour of prep makes a big impact.
This is what research has found and why a lot of focus is on getting kids to do any studying for anything at all.
Many kids do zero homework and zero studying. Getting them to 1 is the hardest part.
This is the biggest actionable problem for these exams. It doesn’t require race or culture or whatever at all. The research says it requires specialized instruction during school - something to achieve focused studying, as opposed to merely watching the clock go down. Difficult for the hardest students but on average, in aggregates, performs well.
My point is that there are a lot of Asian students at Harvard who did 10 hours of test prep for the SAT. They didn’t go to cram school. There are also students who DID go to cram school. I myself studied about 10 hours for the SAT.
You don’t need cram school to improve test scores. You need some studying instead of none at all.