1. The results you list are just average. There could be a bimodal distribution. 2. What those studies call coaching isn’t remotely comparable to years of 20 h

1. The results you list are just average. There could be a bimodal distribution. 2. What those studies call coaching isn’t remotely comparable to years of 20 hour a week cram school. 3. Of course the SAT is coachable. How do you think you learn the math techniques and vocabulary in the first place? If it’s not possible to increase your vocabulary, how do people learn new languages? 4. The percentage of students who make a perfect score on a similar test, the ACT, has increased by 5x in the last five years while the average score has only risen slightly. Clearly a subset of test takers has figured out a way to reliably prep for the test.