title: Biology of human intelligence.
abstract: The article presents a brief review of the genetic aspects of intelligence as measured by IQ tests. The results from family and twin investigations seem to agree in as much as high heritabilities for IQ can be calculated. There are, however, a large number of insecurities and sources of error which invite to criticism. Although, at present, it is justified to assume that genetic factors contribute substantially to variations in IQs, it would be premature to claim that genetic and other causes of variation could be expressed in precise figures. It seems doubtful if this situation could be further improved by continued use of IQs in genetic investigations. It should be more profitable to use other entities, such as well-defined special abilities, which could be designed directly for genetic analyses.
mesh_terms: D004777:Environment; D005260:Female; D005796:Genes; D014644:Genetic Variation; D006801:Humans; D007360:Intelligence; D011247:Pregnancy; D011584:Psychology; D012959:Socioeconomic Factors; D014427:Twins