As Stanley Sue and Sumie Okazaki pointed out in their 1991 American Psychologist paper, Asian American Educational Achievements: A Phenomenon in Search of an Explanation, the parenting styles and values found in East Asian-American homes tend to correlate with lower test scores when they are found in white homes.
The Results showing higher grades for the Asian adoptees is particularly interesting, becuase of the control of white adoptees unique to this study. If Asian academic success was really due to some special set of academic values inculcated by Asian parents (something not demonstrated by the data to begin with), then why do Asians do better academically than whites even when they are raised by white parents?
The gap between whites and Asians fluctuated from 19 to .09 in the NAEP data while the gap in the adoption data is from 1/3 to 3 times larger. This is consistent with the Sue and Okazaki paper above which showed that contrary to popular anecdotes, the values that lead to higher academic grades are actually found more often in white homes. In other words Asian-Americans perform highly despite their Asian home cultural environment not because of it.Seems like a good case for taking Amy Chua's advice with a grain of salt, or at least for trying to get a better understanding of what impact (if any) parental styles can have, and why.