Human Varieties

This post is a quick update on my in-depth review of group differences in the SAT, occasioned by the publication of the College Board’s reports on the SAT scores of the 2023 high school graduate cohort. Using national-level test data as well as data from selected states, I will examine how the most recent results relate to the trends that I previously identified.
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This article reports racial gaps in the LSAT scores for Canada (2019-2023). By using the threshold method designed by La Griffe du Lion (2007), the standardized effect sizes are computed from the proportions of members of each groups who attain specific score ranges. Results are compared with U.S. gaps in the Law School Admission Test (LSAT) and Medical College Admission Test (MCAT) scores. Details of the analysis is available here.

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We recently published the IQ scores for major ethnic groups, based on the broadly representative Adolescent Brain Cognitive Development sample. These ethnic averages correlated very strongly (r = .90 to .94) with scholastic aptitude scores (SAT or ACT scores) based on nationally representative samples of American-born college students between the years 2012 and 2020.  The aptitude scores came from the NPSAS surveys, which, unfortunately, have a limited number of ethnic classifications.

As Dalliard noted, understanding racial/ethnic differences in aptitude tests is important since it is a guide to the composition of the USA’s future cognitive elite.  Since different ethnic groups have different political interests, which, in turn, shape policy, understanding the cognitive capital of ethnic groups is essential to predicting the trajectory of the USA in the coming century.

While no open-source national surveys provide data on SAT/ACT scores decomposed by detailed ethnic groups, Common Application provides some data for USA citizens and residents.  Common App is an undergraduate college admission application service that allows one to apply to over one thousand member colleges in the USA. While the data sample is large, with over 1 million applicants each year, several issues have been reported by Freeman et al. (2021):

• The percentage of applicants reporting a test score fell from 70 and 73% in 2018-19 and 2019-20 to 40% in 2020-21. This is likely due to 89%  of Common App’s members (900+ colleges) no longer requiring SAT/ACT for admission in 2020-21.
• Nearly 60% of applicants applied from ZIP Codes in the top 20% of the median household income distribution. The decline in reporting rates between 2019-20 and 2020-21 was greater in lower-income communities.
• Underrepresented minorities (not including Asians) report test scores at lower rates than non-underrepresented minorities (71% vs 77%). The drop in reporting rates between 2019-20 and 2020-21 was larger for underrepresented minorities (31% vs 47%).
• In 2019-20, 78% of non-first-generation students reported test scores versus 69% of first-generation students while in 2020-2021 the rates were 48% and 30%.
• Applications to private, more selective institutions were the most likely to include test scores (83% in 2019–20 and 44% in 2020–21), while applications to private, less selective institutions were the least likely to include test scores (67% and 28%).

The high rates of missing test scores, especially for low-achieving groups,  may mean that certain group averages are biased. Moreover, many ethnic groups suffer from ethnic attrition (Emeka, 2019), in which case group identification is correlated with aptitude. To illustrate, in the case of Nigerian-Americans, Emeka (2019) noticed that Nigerians residing in poor families with parents who have not completed high school or college degrees are much more likely to drop out of the Nigerian group in favor of the African American or Black group. This is because for them, “it is not Nigerian not to go to college”.

Those caveats noted, with respect to test scores, which are reported by Kim et al. (2022), the numbers are more or less as expected. Scores for the average Asian group, average White, average Black, and Native Hawaiian or Pacific Islander are 1382, 1278, 1108, and 1181, respectively. Applicants who did not report racial/ethnic information score (1378) higher than the non-underrepresented minorities (1297). Among Asian ethnicities, Asians from India, China, Korea, Japan, Malaysia, and “None provided” scored substantially higher (around 1400 vs 1300 or less) than Asians from Cambodia, Philippines, Vietnam, Pakistan, Other Southeast, or Other South Asia (Figure 2a).

The following table reports the SAT/ACT means by race/ethnicity, including mixed races, as well as Hispanic groups by both region and race. The columns display the N (unadjusted), % of reports, average SAT/ACT, GPA, N (adjusted for % of reports), SAT/ACT in IQ metrics. The IQ metric SAT/ACT scores were computed using the NPSAS20 total SAT/ACT standard deviations.

¹SAT/ACT average
²Real N estimated by multiplying N column by % Reports

Despite issues with the data that were pointed out above, one clearly notices the strong similarity between these IQ-metric SAT/ACT scores by race/ethnicity, including various mixed-race categories, and the IQ-metric SAT/ACT estimates from the NPSAS reported in a previous post.

The full dataset made available by Common App can be found at the following link.  See also the following report. Additional data is included in the file such as AP scores, the number of academic honors reported, and household income.

References

1. Freeman, M., Magouirk, P., & Kajikawa, T. (2020). Applying to college in a test‐optional admissions landscape: Trends from Common App data.
2. Kim, B.H., Freeman, M., Kajikawa, T., Karimi, H., & Magouirk, P. (2022). Unpacking applicant race and ethnicity, part 2: disparities in key indicators of applicant readiness and resources across detailed backgrounds. Common Application.

The SAT is the most popular standardized test used for college admissions in the United States. In principle, SAT scores offer a good way to gauge racial and ethnic differences in cognitive ability. This is because, psychometrically, the SAT is just another IQ test–that is, it is a set of items the responses to which can be objectively marked as correct or incorrect.[Note 1] Unsurprisingly, SAT scores correlate strongly with scores from other IQ tests (Frey & Detterman, 2004). It is also advantageous that SAT-takers are generally motivated to get good scores, and that large numbers of young people from all backgrounds take the test each year, enabling precise estimation of population means.

However, the SAT has at least two major limitations when used for group comparisons. Firstly, it is a high-stakes college entrance test, which means that it is a target for intense test preparation activities in ways that conventional IQ tests are not, potentially jeopardizing its validity as a measure of cognitive ability. Secondly, taking the SAT is voluntary, which means that the participant sample is not representative but rather consists of people who tend to be smarter and more motivated than the average.

This post will attempt to address these shortcomings. I will investigate whether racial and ethnic gaps in the SAT are best understood as cognitive ability gaps, or if other factors make a significant contribution, too. An important method here is to compare the SAT to other tests that are not subject to extraneous influences such as test prepping. Another goal of the post is to come up with estimates of racial/ethnic gaps in the test that are minimally affected by selection bias. This can be done with data from states where entire high school graduate cohorts take the SAT. Other topics that will receive some attention in the post include ceiling effects, predictive validity, and measurement invariance.

Because racial/ethnic gaps in the SAT have changed over time, an essential part of the analysis is understanding these temporal trends. In particular, Asian-Americans have performed extraordinarily well in the test in recent years. Getting a better handle on that phenomenon was a major motivation for the post. Comparisons of trends in the national and state-level results turned out to be informative with respect to this question.

The post is multipronged and somewhat sprawling. This is because the (publicly available) SAT data do not yield straightforward answers to many important questions about racial and ethnic differences. The only way to get some clarity on these issues is to examine them from multiple angles, none of which alone supplies definitive answers, but which together, hopefully, paint a reasonably clear picture. I have relegated many technical details of the statistical methods used, as well as many ancillary analyses, to footnotes so as make the main text less heavy-going. The data and R code needed to reproduce all the calculations, tables, and graphs in this post are included at the end of each chapter, or, in the case of some ancillary analyses, in the footnotes.

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