{"id":1265,"date":"2021-06-25T22:51:06","date_gmt":"2021-06-25T22:51:06","guid":{"rendered":"https:\/\/opentextbc.ca\/psyclanguage\/chapter\/language-development\/"},"modified":"2023-05-18T22:51:02","modified_gmt":"2023-05-18T22:51:02","slug":"language-development","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/psyclanguage\/chapter\/language-development\/","title":{"raw":"5.1 Language Development","rendered":"5.1 Language Development"},"content":{"raw":"

Chomsky and the Poverty of the Stimulus<\/h1>\r\nChomsky demonstrated that children acquire linguistic rules or grammar without an inexhaustive sample of the acquired language. In other words, children cannot learn the rules of grammar by mere exposure to a language (Chomsky, 1965). For one thing, children hear an imperfect input. Adult speech is full of slips-of-the-tongue, false starts and errors. Sometimes there are contractions such as gonna<\/em> and wanna<\/em> and words are not necessarily separated in continuous speech. There is also a lack of examples of all the grammatical structures in a language for children to derive all linguistic rules from analysing the input. All of these phenomena are often labelled the \u201cpoverty of the stimulus\u201d (Berwick, Pietroski, Yankama, & Chomsky, 2011). Poverty of the stimulus is often used as an argument for universal grammar. This is the claim that all languages have some underlying common structure within which all surface structures of language emerge.\r\n

Language Development<\/h1>\r\nLanguage development is perhaps one of the greatest mysteries in psycholinguistics. The rapidity of first language acquisition is astounding to anyone who has tried to learn a second language as an adult. This process can be broadly divided into stages based on the characteristics of the infants\u2019 output. However, we must note that output doesn\u2019t always assure us a clear picture of the cognitive processes that are going on within the infants\u2019 minds.\r\n\r\nAs seen in Figure 5.1, infants make [pb_glossary id=\"1423\"]vegetative sounds[\/pb_glossary] from birth. These include crying, sucking noises and burps. At around 6 weeks, we start getting [pb_glossary id=\"1424\"]cooing sounds[\/pb_glossary] followed by [pb_glossary id=\"1425\"]vocal play[\/pb_glossary] between 16 weeks and 6 months (Stark, 1986). This vocal play involves sounds that appear similar to speech but containing no meaning. [pb_glossary id=\"1426\"]Babbling[\/pb_glossary] is observed between 6 to 9 months. This is different from vocal play in that it contains true syllables (generally CV syllables as in \u2018wa wa\u2019 for \u2018water\u2019). Children produce [pb_glossary id=\"1427\"]single-word utterances[\/pb_glossary] around 10 to 11 months followed by an extraordinary expansion of [pb_glossary id=\"1428\"]vocabulary[\/pb_glossary] around 18 months. At the same time, we start to get [pb_glossary id=\"1429\"]two-word utterances[\/pb_glossary]. We also start to get [pb_glossary id=\"1432\"]telegraphic speech[\/pb_glossary]. These are utterances which lack grammatical elements (Brown & Bellugi, 1964). Grammatically complex utterances emerge around two and a half years.\r\n\r\n[caption id=\"attachment_488\" align=\"aligncenter\" width=\"700\"]\"A Figure 5.1 Language Acquisition Milestones[\/caption]\r\n\r\nResearch methods that we can employ with adults is not always possible with infants. One technique is the [pb_glossary id=\"1433\"]sucking habituation paradigm[\/pb_glossary]. This paradigm measures the rate of sucking an artificial pacifier as a measure of interest by the infant in a novel stimulus. It has been observed that babies prefer novel stimuli as opposed to stimuli that are familiar. If they are presented with habituated (or familiar) stimuli and then a novel stimulus pops up, the rate of sucking increases. This can be used to see whether an infant can detect the difference between who stimuli. Another technique is the [pb_glossary id=\"1434\"]preferential looking technique[\/pb_glossary]. Here children look longer at scene that are consistent with what they are hearing. Using such techniques (and others), psycholinguists try to determine at what age children understand the difference between phonemes, morphemes and understand syntax.\r\n

Imitation<\/h2>\r\nThe simplest form of [pb_glossary id=\"1435\"]language acquisition[\/pb_glossary] would be simple [pb_glossary id=\"1436\"]imitation[\/pb_glossary] of adult language. While children do imitate adult behaviour to some extent, this alone cannot account for language development. The sentences produced by children acquiring language do not show imitation of adults. Children often make errors that adults don\u2019t make. However, imitation may play a role in the acquisition of accents, speech mannerisms and specialized vocabulary.\r\n

Conditioning<\/h2>\r\nSkinner (1957) argued that language acquisition happens through the same mechanisms of operant [pb_glossary id=\"1437\"]conditioning[\/pb_glossary] that operated on other human and animal behaviour. However, adults generally do not encourage children to speak like them. On the contrary, adults often imitate the childish speech of children when speaking to them. If any correction is made, it is regarding the accuracy of the statements rather than their syntax.\r\n\r\nAnother observation that learning theories cannot predict is the pattern of acquisition of irregular verb and noun forms. \u00a0Saying *gived<\/em> instead of gave<\/em> or *gooses<\/em> instead of geese<\/em> are some examples of this. \u00a0Children generally show a pattern of correct imitation of the stem but then incorrect production. These incorrect productions are usually because of over-regularization of the past tense or plural forms of the stems. Finally, children produce the correct forms. This is an example of U-shaped development: performance starting off well, then deteriorating before improving. In essence, language acquisition appears to be based on learning rules rather than learning associations.\r\n

The Language Acquisition Device<\/h1>\r\nChomsky (1965) argued for the existence of a [pb_glossary id=\"1438\"]language acquisition device (LAD)[\/pb_glossary]. This is hypothesized to be an innate structure separate from intellectual ability or cognition. If the poverty of the stimulus is true, then children need something in additional to language exposure to arrive at language competency. The language acquisition device was later replaced by the concept of [pb_glossary id=\"1439\"]universal grammar[\/pb_glossary]. According to this idea, the child has innate rules of inference that enable them to learn a language. This would be a set of parameters that constrain and guide language acquisition. As languages vary in terms of their grammar, syntax and morphology, Chomsky hypothesized that language learning was essentially setting parameters using input from exposure to a language that in turn set other parameters automatically. In other words, languages cannot vary in any way possible with infinite variety. There are basic parameters that influence each other.\r\n\r\nWe can look at some examples of parameter setting across language. For example, if a language has subject-verb-object (SVO) word order, then question words (what, where, who, how) would come at the beginning of the sentence while a language that is subject-object-verb (SOV) would put them at the end.\r\n