In my opinion, language development occurs during a specific time in a person’s life, which is known as a critical period. First language acquisition happens due to exposure to the language between age two and puberty (Hartshorne et al., 2018). After this stage, it becomes more difficult for an individual to learn the language. The existence of the critical period is exemplified by the case of Genie Wiley and bilingualism.
Genie Wiley is a girl who grew completely isolated from human contact because she was confined by her parents and denied important childhood milestones. When she was rescued at the age of thirteen years and nine months, Genie could not speak (Carroll, 2016). She was exposed to language for several years after her rescue. Although Genie developed lexicon, she could not acquire grammar (Carroll, 2016).
The case of Genie supports the critical period hypothesis (CPH) because it shows that developing language after a certain age is difficult or in this particular case, impossible. Studies on bilingualism and language development also support the critical period theory. According to a study conducted at the Massachusetts Institute of Technology, people are skilled at learning a second language up to the age seventeen or eighteen years (Trafton, 2016). Additionally, they can only achieve the proficiency level of a native speaker if they start learning it by age ten, which confirms the CPH.
I would advise parents to expose their children to language early in their lives. During this stage, the brain actively engages in language processing. Children can easily learn new words and then how to form sentences from these words. For a first language, language acquisition after puberty becomes more challenging or even unattainable in some cases. Learning a second language is also harder in adulthood. Due to these findings, it is advisable for parents to initiate language development when their children are still young.
References
Carroll, R. (2016). Starved, tortured, forgotten: Genie, the feral child who left a mark on researchers. The Guardian. Web.
Hartshorne, J. K., Tenenbaum, J. B., & Pinker, S. (2018). A critical period for second language acquisition: Evidence from 2/3 million English speakers. Cognition, 177, 263-277. Web.
Trafton, A. (2018). Cognitive scientists define critical period for learning language. Massachusetts Institute of Technology News. Web.