No support for the hereditarian hypothesis of the Black–White achievement gap using polygenic scores and tests for divergent selection

Abstract

Objectives: Debate about the cause of IQ score gaps between Black and White populations has persisted within genetics, anthropology, and psychology. Recently, authors claimed polygenic scores provide evidence that a significant portion of differences in cognitive performance between Black and White populations are caused by genetic differences due to natural selection, the "hereditarian hypothesis." This study aims to show conceptual and methodological flaws of past studies supporting the hereditarian hypothesis.Materials and methods: Polygenic scores for educational attainment were constructed for African and European samples of the 1000 Genomes Project. Evidence for selection was evaluated using an excess variance test. Education associated variants were further evaluated for signals of selection by testing for excess genetic differentiation (F st ). Expected mean difference in IQ for populations was calculated under a neutral evolutionary scenario and contrasted to hereditarian claims.Results: Tests for selection using polygenic scores failed to find evidence of natural selection when the less biased within-family GWAS effect sizes were used. Tests for selection using F st values did not find evidence of natural selection. Expected mean difference in IQ was substantially smaller than postulated by hereditarians, even under unrealistic assumptions that overestimate genetic contribution. Conclusion:Given these results, hereditarian claims are not supported in the least.Cognitive performance does not appear to have been under diversifying selection in Europeans and Africans. In the absence of diversifying selection, the best case estimate for genetic contributions to group differences in cognitive performance is substantially smaller than hereditarians claim and is consistent with genetic differences contributing little to the Black-White gap.

Wrestling with Social and Behavioral Genomics: Risks, Potential Benefits, and Ethical Responsibility

“…For instance, if ethically or scientifically problematic group‐comparison research were already being conducted and taken seriously, that could be one factor in allowing responsible, better‐skilled scientists to engage in and show the limitations of similar research; arguably, that would not entail unacceptable incremental risk and might indeed mitigate harm from others’ work 133 …”

“…For instance, if ethically or scientifically problematic group-comparison research were already being conducted and taken seriously, that could be one factor in allowing responsible, better-skilled scientists to engage in and show the limitations of similar research; arguably, that would not entail unacceptable incremental risk and might indeed mitigate harm from others' work. 133 Similarly, in some cases where observed phenotypic differences between groups are already well-known, a genomic explanation might be more likely to be destigmatizing than stigmatizing-say, if the prevailing explanation overemphasizes personal responsibility. For instance, although obesity is not disfavored in all social groups, in many, it is often assumed to be the result of weak character (for ex-ample, laziness, lack of impulse control, or lower intelligence).…”

Defense against dark anthropology

“…Biological anthropology has to reckon with very real consequences of all published material in our field. When studies fish for statistical support for polygenic risk scores in traits that are driven by social environments, such as educational attainment or violence, they are cited by white supremacists as support for violent or terrorist acts (Bird 2021; Panofsky, Dasgupta, and Iturriaga 2021). When minorities are largely excluded in medical genetic trials, those same individuals become at risk of being prescribed ineffective medication (Krainc and Fuentes 2022).…”

Ending genetic essentialism through genetics education

“…Population geneticists have expressed skepticism toward the essentialist argument that genes are the best explanation for social disparities between races because of the ontological and epistemic weaknesses in this argument. 6 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 Skepticism is warranted because (1) genetic differentiation between human geographic groups is relatively small when compared to variation within groups, 29 (2) differences in the social and physical environments of racial groups are relatively large, 1 and (3) you inherit your genes with your environment. 35 , 37 Since no scientist has ever conducted a causal inference study on the genetic basis of racial disparities that conclusively ruled out the confounding effect of the environment, 30 , 31 , 37 , 38 skepticism is a defensible attitude toward essentialist claims about the genetic etiology of inequality.…”

“…Such skepticism is also defensible because tests of divergent selection using polygenic scores associated with educational attainment provide no support for the hypothesis that the Black-white achievement gap is due to natural selection. 36 Polygenic variation associated with educational attainment is also inconsistent with the bell-curve hypothesis. 39 …”