There is a broad consensus that language is, in most right-handers and in a substantial part of left-handers, controlled by the left hemisphere. This seems to be, at least in part, genetically determined, as neuroanatomical asymmetries have been observed already prenatally (e.g. a larger left planum temporale). Left hemisphere lesions in adolescents and adults accordingly lead to persistent language deficits. However, this is not the case in lesions acquired prenatally or in early childhood.