Commentary on Fuerst et al: Do Human Populations Differ in Their Mental Characteristics?
Human populations may differ genetically not only in their anatomy but also in their mental characteristics. Our species is not too young for such differentiation. In fact, human genetic evolution has proceeded faster over the past 10,000 years than over the previous million. With the rise of farming, and social complexity, humans were no longer adapting solely to a limited range of natural environments. They were adapting to an ever-widening range of cultural environments, each of which imposed its demands on mind and body. Thus, mental characteristics do not have the same adaptive value in all environments, and differences in adaptive value will lead, over time, to genetic differences. Are the latter large enough to explain IQ differences between human populations? That question has led to studies of people who are ancestrally diverse but raised in the same environment, such as transracial adoptees. Unfortunately, the environment can never be fully equalized. We should measure genetic differences directly, and a promising step in that direction has come with research to identify alleles associated with educational attainment. There is no need to identify all of them, just a large enough sample. These “witnesses” can then be questioned to determine the strength and direction of natural selection, and its consequences. Also promising is the study of IQ and ancestry in ethnically mixed groups. This research instrument is not without problems. Large continental populations often have high-achieving minorities who may contribute disproportionately to the founding of new groups or to admixture with old ones. In addition, natural selection can alter the distribution of alleles within a new group, even after a few generations. Keywords: Ashkenazi Jews, Cognitive ability, Educational attainment, Gene-culture coevolution, IQ, Parsis, Polygenic scoreDownload PDF