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General intelligence (g) varies with ethnicity, as do genetic variants associated with educational attainment (Lasker et al., 2019, p. 445)
Bryan Pesta was fired from a tenured university position for a study he coauthored in a peer-reviewed journal. No one actually disputed his findings. It was simply taken for granted that they could not be true.
Three years ago I contributed a paper to a special issue of Psych. One of the other contributors, Bryan J. Pesta, coauthored a paper on “Global Ancestry and Cognitive Ability” (Lasker et al., 2019). It was one of several recent studies that had used genetic data to understand how populations differ on average in their capacity for intelligence.
Pesta and his coauthors looked at data from an existing neurodevelopment study of 9,421 participants from Philadelphia. A little over half of them were European American, and a third were African American. They had all been genotyped and had all taken a battery of cognitive tests.
The study produced several findings:
Almost 15 IQ points separated the African American participants from the European American participants. About three quarters of the difference was due to general intelligence (g).
Among the African Americans, general intelligence correlated with the degree of European admixture.
The correlation was modestly reduced, but not eliminated, when controlled for parental education. Controlling for skin color had no effect. Although skin color does correlate with European admixture, it evidently has a less direct relationship to general intelligence. This finding therefore eliminates “colorism” (discrimination in favor of lighter-skinned African Americans) as a possible cause.
As much as 20-25% of the difference in general intelligence between the African Americans and the European Americans was explained by genetic variants associated with educational attainment. By comparison, the same variants explain only 11-13% of the variation in educational attainment among individuals. This is because between-population variation tends to have more adaptive significance, in the sense that it is more likely to be shaped by differences in natural selection. Conversely, within-population variation tends to be “noise” that is less likely to produce real physical, mental, or behavioral differences. If individuals belong to the same population, they share the same environment of adaptation, be it the natural environment (climate, food sources, etc.) or the cultural environment (way of life, language, social norms, etc.).
Although these genetic variants predicted general intelligence in both groups, the predictive power for the African Americans was only 20% of the predictive power for the European Americans. This finding is consistent with a growing consensus that the genetic architecture of intelligence is different in the two groups. Because the genetic variants have been identified in Europeans or European Americans, they may contribute less to the capacity for intelligence in people of African descent. In addition, other variants may be found only in African populations and thus remain to be identified.
For the above findings, Bryan Pesta would be fired from his tenured position at Cleveland State University. The whole affair is described in The Chronicle of Higher Education (Standifer, 2022). At no point did anyone actually dispute his findings. It was simply taken for granted that they could not be true. And that’s that.
Please don’t argue that Bryan Pesta unconsciously looked for data that would provide the findings he wanted. The data had already been collected by another research team for a completely different purpose. So put aside The Mismeasure of Man and tell Stephen Jay Gould to go back to sleep.
This story isn’t over. People are curious, and curiosity ends up finding a way—despite the barriers we erect. Below is a screen shot of the paper’s access statistics (Hint: The Chronicle’s article came out on October 13).
References
Lasker, J., B.J. Pesta, J.G.R. Fuerst, and E.O.W. Kirkegaard. (2019). Global Ancestry and Cognitive Ability. Psych 1(1):431-459. https://doi.org/10.3390/psych1010034
Standifer, C. (2022). Racial Pseudoscience on the Faculty. A professor’s research flew under the radar for years. What finally got him fired? The Chronicle of Higher Education. October 13. https://www.chronicle.com/article/racial-pseudoscience-on-the-faculty?cid2=gen_login_refresh&cid=gen_sign_in