Continental Genetic Ancestry Source Correlates with Global Cognitive Ability Score

Abstract

The origins of between-group variation in cognitive ability have been a source of controversy for decades. In this pre-registered study, I tested the hypothesis that such differences are entirely environmental by examining the correlation between the proportion of individuals’ genetic heritage that originates on different continents with their total cognitive test score. In a sample of 193 Hispanic Americans and African Americans, it was found that the proportion of European genetic heritage was positively correlated (r = .277 to .300, p<.001) with the total cognitive test score. This makes any assertion of a purely environmental cause of mean group differences in cognitive ability less probable. One possible explanation is that the ancestors of Europeans experienced stronger selection pressures for high cognitive ability than the ancestral groups for Africans and Native Americans. However, this study may or may not generalize to other groups or a worldwide sample. Molecular genetics data suggest that most genetic causes are not specific for European (or any other continental) heritage. Such genetic variations are polymorphic in most human populations. Any person — from any demographic group — with a high proportion of such alleles is more likely than others to have high general cognitive ability.