One significant area in which private school students did excel: SAT scores. Students in private schools performed constantly better on the test than public school students. The study’s authors point out that this does not imply that private schools are any better at teaching subject matter. They offer two possible explanations for this finding:
- Private schools are better at teaching preparation for the test.
- The admissions process at private schools tends to choose students with higher IQ scores, and aptitude tests like the SAT are a better measure of IQ than subject achievement tests.
Regardless of the reason for the difference, the result is that graduates from private schools are somewhat more likely to get admitted into very prestigious colleges.
The second exception that the study found was limited to a very specific type of private school. Catholic schools that are run by holy orders, such as the Jesuits, did show consistently positive academic effects. However, this is a relatively small percentage of parochial schools, since the majority of Catholic institutions are run by a local diocese instead of a holy order.