Specific language Impairment

     There are, however, exceptions. Mental retardation or deafness can block a natural path to acquiring a language. Chemical influences or physical accidents suffered by a fetus, or genes that are activated in abnormal ways, can make normal language learning difficult for otherwise healthy, intelligent children. A number of these diversities have been lumped by psychologists under the general name of Specific Language Impairment, or SLI

     These SLI disorders relate only to language ability. They are not part of some general problem of cognitive development, intelligence, emotional trauma, or impoverished environment. The fact that some children are apparently born with brains that function well in all skills but language may mean that there are specific genes that code for language-processing regions of the brain and that may go awry. All the language disorders are more common among boys and girls, and all have a tendency to run in families. SLI are mainly caused by the failure of genes.