Language and Genes

Abstract

Abstract The development of spoken language involves the acquisition of a complex system of knowledge and processing mechanisms that recruits a number of neural systems. These neural systems depend on numerous genetically influenced biological functions that provide for experience dependent learning. That language development and use entail genetic mechanisms is clear. A substantial literature shows that individual differences in language are partially heritable. This evidence of heritability has now motivated efforts to uncover specific genetics mechanisms using modern molecular genetics. To date, one gene, FOXP2 , has been shown to be associated with speech and language. However, it is not appropriate to conclude that FOXP2 contains the human language faculty. Instead, it likely participates with many genetic systems to support language development. What these genetically influenced systems are is only beginning to be revealed. Key Concepts: There is considerable support for a role for genes in language development and function. Twin studies along with adoption studies show that individual differences in language are partially attributable to genetic factors. There is little evidence that vocabulary and grammar are differentially influenced by genetic factors. Heritability of language increases through childhood. Twin research suggests that the genetic influence on language development is shared with nonlanguage cognitive skills. Substantial evidence shows that FOXP2 plays an important role in the neurobiology of language via it regulation of the expression of other genes. CNTNAP2 is a downstream regulatory target of FOXP2 that has been associated with developmental language impairment. Future progress in understanding a complex trait such as language may come from understanding genetic mechanisms controlling the expression levels of genes (eQTLs).