title: Differential fertility and normal selection for IQ: some required conditions in their investigation.
mesh_terms: D001741:Black or African American; D005075:Biological Evolution; D005053:Eugenics; D005191:Family Characteristics; D005298:Fertility; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests / Q000379:methods; D012107:Research Design; D014481:United States