Look at the effect sizes of different factors that affect intelligence.
Child and prenatal nutrition and parasite load are much larger factors in IQ variations between population groups. Genetic variation between groups is much smaller and the effect size is very small. In practice it disappears into variation between individuals.
Child and prenatal nutrition and parasite load are much larger factors in IQ variations between population groups. Genetic variation between groups is much smaller and the effect size is very small. In practice it disappears into variation between individuals.
https://www.ncbi.nlm.nih.gov/books/NBK62514/