Race, Ethnicity, and the Scarr-Rowe Hypothesis: A Cautionary Example of Fringe Science Entering the Mainstream

Abstract

In 2020, Pesta et al. published an article entitled “Racial and Ethnic Group Differences in the Heritability of Intelligence: A Systematic Review and Meta-Analysis” in the journal Intelligence. The authors framed their analysis as an examination of the Scarr-Rowe hypothesis, which holds that the heritability of intelligence varies as a function of socioeconomic status. Pesta et al. concluded that the heritability of intelligence does not differ across racial and ethnic groups in the United States. They claimed their results challenge the Scarr-Rowe hypothesis and support the hereditarian position that mean differences in IQ among racial and ethnic groups are attributable to genetic differences rather than environmental disparities. In this commentary, we outline severe theoretical, methodological, and rhetorical flaws in every step of Pesta et al.’s meta-analysis. The most reliable finding from Pesta et al. is consistent with the Scarr-Rowe hypothesis and directly contradicts a hereditarian understanding of group differences in intelligence. Finally, we suggest that Pesta et al. serves as an example of how racially motivated and poorly executed work can find its way into a mainstream scientific journal, underscoring the importance of robust peer review and rigorous editorial judgment in the open-science era.