That's the average, which tells us nothing about the distribution. If you're looking at the top n% of scores, the distribution is important.
Furthermore, those studies weren't looking at kids who were prepping for 2 hours a day like many kids with perfect and near perfect scores are doing.
Also here's a study from 2017 that shows an average gain of 115 points with only 20 hours of practice (plus 16,000 students who gained more than 200 points).
Another issue is that scores have gone up dramatically over the last 20 years, so given that and the fact that Asian American kids are so overwhelmingly dominant, I think preparation being a major factor is the most likely explanation.
Furthermore, those studies weren't looking at kids who were prepping for 2 hours a day like many kids with perfect and near perfect scores are doing.
Also here's a study from 2017 that shows an average gain of 115 points with only 20 hours of practice (plus 16,000 students who gained more than 200 points).
https://www.collegeboard.org/releases/2017/average-score-gai...
Another issue is that scores have gone up dramatically over the last 20 years, so given that and the fact that Asian American kids are so overwhelmingly dominant, I think preparation being a major factor is the most likely explanation.