Genes, Chromosomes, and Disease: From Simple Traits, to Complex Traits, to Personalized Medicine

7. Genes and IQ: an unfinished story

Why would IQ be included in a book on genes and disease? The reason is that low IQ has often been equated with poor heredity and treated as if it were a disease. From early in the last century until today, those scientists with a hereditarian (as opposed to an environmental) bent have argued that cognitive deprivation is largely the result of a less-than-satisfactory genetic background. This chapter briefly outlines the fraught history relating genes and environment to intelligence. In the first part of the last century, the presumed genetic basis of “feeblemindedness,” as it was called, served as the “scientific” basis for the involuntary sterilization statutes passed by many states in America, at the provincial ...