Language development is a part of normal human development, since language is something that almost all children acquire. Yet, inadequate environmental circumstances have been known to interrupt this process in children. An environment with the proper stimulation appears to be a critical factor for language development.
Evolution
Linguist Noam Chomsky believed that children are born into the world with biological hardwiring for language, which he described as a language acquisition device. Although not a physical brain structure, this is the brain's ability to learn the rules of language.
Timeframe
The preschool years are thought to be the critical period for language learning. Developmental psychologist John Santrock cites the notion that these are years in which language learning occurs rapidly and with ease.
Brain Activity
Studies have found activity in the brain that is thought to result from the increase in language ability in approximately the first 18 months to 2 years of life. Santrock notes that infants show greater activation in the left side than in the right side of the brain when listening to speech-related sounds.
Case Study
The story of a 13-year-old California girl named Genie, a child who was subjected to severe inhumane treatment including social isolation during the 1970s, shows some support for the critical period for language theory. Genie's parents kept her bound to a potty throughout the day allowing only for the movement of her hands and feet. At night, she was confined to a straightjacket inside of a covered crib. The author describes that Genie was beaten if she made noises and her only form of communication was through growls, never words. Consequently, Genie was not able to fully develop language skills such as the ability to ask questions or understand rules of grammar. With intensive therapy, Genie was ultimately able to string together word phrases.
Considerations
Language delays resulting from isolation are not the same as autism or mental retardation, according to neuroscientist Heather Stewart. Children with autism and mental retardation experience delays caused by aberrations in normal development, whereas isolated children do not have proper human models to teach language skills and therefore cannot develop to their full potential.
References
- University of Washington: Feral Children
- "A Topical Approach to Lifespan Development"; John W. Santrock; 2007
