Туғаннан екі тілділік: даму және артықшылықтары

Bilingualism by learning two languages from birth

Simultaneous bilingualism is a form of bilingualism that takes place when a child becomes bilingual by learning two languages from birth. According to Annick De Houwer, in an article in The Handbook of Child Language, simultaneous bilingualism takes place in "children who are regularly addressed in two spoken languages from before the age of two and who continue to be regularly addressed in those languages up until the final stages" of language development. Both languages are acquired as first languages. This is in contrast to sequential bilingualism, in which the second language is learned not as a native language but a foreign language.

It is estimated that half of the world is functionally bilingual, and the majority of those bilinguals are 'native speakers' of their two languages. Wölck has pointed out that there are many "native bilingual communities", typically in South America, Africa, and Asia, where "monolingual norms may be unavailable or nonexistent". include the ideas that bilingual children will not reach proficiency in either language and that they will be cognitively disadvantaged. Many studies in the early 20th century found evidence of a "language handicap" in simultaneously bilingual children, linking bilingualism with a lower intelligence. However, many of these studies had serious methodological flaws. analytical skill, and metalinguistic awareness. However, most studies agree that simultaneous bilinguals do not have any definitive cognitive advantage over monolinguals. Despite these findings, many therapists and other professionals maintain that simultaneous bilingualism can be harmful for a child's cognitive development. One side argues that only one language should be spoken until fluently spoken and then incorporate the second language. The other side argues that the child, whether simultaneously bilingual or not, would still have speech issues. Some bilingual families have chosen to stop speaking a language after hearing about the supposed negative developmental effects of child bilingualism from people in authority. People were once concerned that being exposed to more than one language would be confusing and cause bilinguals to lag behind their monolingual peers in language development, but multiple researchers have refuted this claim. Bilinguals appear to acquire the same milestones—including when they say their first word, when they say their first telegraphic phrase, and when they obtain a vocabulary of fifty words—within the "normal range of variation" of monolingual development in each language. This is an analysis of overall vocabulary in bilinguals, as this is the more accurate and appropriate measure of language development in bilinguals. Analyzing only one of a bilingual individual's languages would seriously underestimate their true vocabulary knowledge. Any vocabulary deficits in one language are likely filled by knowledge in the other language, suggesting a likelihood that bilinguals know more vocabulary words than monolinguals in general. To this effect, researchers emphasize the importance of assessing overall vocabulary in bilinguals because assessing only one is an underestimation of their true knowledge, and when assessed in overall vocabulary bilingual children were no different from monolingual children in terms of language development.

Studying bilingual acquisition is important because it may have real effects on academic performances for bilingual children in school. Research has shown that vocabulary size is an indicator of academic performance and literacy. It is known that different contexts can cause differences in vocabulary in each language. Despite these differences, Study has provided evidence against the popular "one parent one language" approach, as it restricted the contexts a child had for interactions and use of that language.

The most influential factor in bilingual language acquisition is the languages spoken by parents to their children, and the languages spoken by others with whom the child comes into contact. This language exposure is called comprehensible input. In a 1984 edition of Bilingual Education Paper Series, Carolyn Kessler claimed that "children develop faster in the language which is used most in their environment", which may or may not reflect the language of the surrounding community. However, bilingual acquisition can also be affected by the amount of input, the separation of input, and the stability of input, as well as attitudes about bilingualism.

It is important to consider amount of input, because not only do the languages of each person affect bilingualism; the amount of time each main input carrier spends with the child also has an effect. It may be the amount of exposure to each language that is the factor for whether or not a bilingual child develops similarly to a monolingual child in each of those languages. Research has shown that children who are exposed less to a language will have "significantly lower receptive vocabulary scores for" that language. By contrast, the receptive vocabulary of bilingual children does not appear to be different from that of monolingual children when 40% to 60% of their language exposure is to that language. Vocabulary size in each language appears to be affected by both the "frequency of exposure" and the "differences in context of exposure" to that language. Varying contexts of exposure provide more opportunities for bilingual children to learn more words. Bilinguals who are exposed to more of one language than another will perform similarly on tasks to monolinguals of that language, but they will lag behind in vocabulary of the other language. In addition to exposure, research has shown that the context of the language exposure and language use also affects vocabulary. Particularly, studies have shown that vocabularies seem to be separated by a "home context" versus a "school context", depending on what language input they are getting in each. Because this pattern was seen across children with different language backgrounds, this suggests the differences in receptive vocabulary could not be attributable to the different cultural contexts, which has been suggested as an alternative explanation.

One particularly fascinating aspect is determining how lexical structures are represented in the brains of bilinguals versus monolinguals, as bilinguals must map two different languages. Particularly, researchers have been interested in determining if a bilingual individual has two separate lexicons for each language or one containing both. found that the language input children received was important in "determining how independent one language will be from the other in the child's mind" (p. 646). Research on how lexical items are accessed in a bilingual brain has tended toward a mixed representation, where there is interconnectivity and some overlapping of the two lexicons but other items stay separated. Spreading activation, a process where similar concepts are activated when their neighbors are activated, is a widely accepted model of lexical access. It has been shown in both bilingual and monolingual individuals, with bilinguals showing activation in both languages during language research tasks. Multiple studies have shown that bilinguals recognize cognate words more quickly than non cognate words, especially identical cognates, which produce the strongest effect. These effects occurred even when the participants knew ahead of time what language the target words would be in. Despite the specific language contexts, both languages are activated, showing that lexical access is not language specific and that top down processing is important in lexical access. Findings suggest that the amount of activation that occurred cross linguistically was related to the similarity between the translation equivalents of the languages. These findings suggest that when bilinguals read sentences, the language of the sentence does not necessarily act as an early cue for the restriction of the individual's lexical search to one language or the other. Rather, this decision is made later. This is similar to semantic priming in monolinguals. When monolinguals read a sentence that is semantically ambiguous (for example, in the sentence He saw the bug "bug" could mean insect or could mean a spy device), they will prime both meanings of the word and then later narrow it down to one. It is first a parallel process and then a serial process. When bilinguals read sentences, they go through a similar process with which language they should interpret the sentence. This interconnectivity of both languages in the bilingual brain can also have effects on the way concepts are represented in the bilingual mind. There is a mutual influence that seems to occur in the bilingual brain. Studies of categorization by bilinguals show that categories are simplified in the brains of bilinguals compared to monolinguals. Specifically, the corresponding category centers (examples of typical category exemplars) were closer together for bilinguals than monolinguals. Additionally, bilinguals showed a pattern of having "less complex category boundaries" (p. 270), which is where atypical exemplars would be placed, and "more similar centers of corresponding categories" (p. 288) than monolinguals. This shows the mutual influence that two languages can have on the representation of concepts in the brain. Many have suggested that bilinguals have weaker connections in their lexical representations than monolinguals (Bialystok, Luk, Peets, & Yang, 2010; Ameel, Malt, Storms, & Van Assche, 2009). It is believed that this is because bilinguals get less practice with each language because they use each less often than a monolingual person uses their language, giving them half of the opportunity "to receive feedback in each language" and deepen their "mappings between words and objects in each language" (p. 272). This model is similar to the revised hierarchical model and suggests the lexicon of a bilingual individual is integrated, containing the words for both languages. This accounts for the simultaneous parallel activation of both languages during language tasks, the late activation of language in semantic processing, and the lack of effects of code switching. This lack of cost for code switching is especially used because they argue that separate lexicons would cause a slower reaction time, which was not indicated in the findings.

Though simultaneous bilingual children learn two languages at once, this does not mean that they speak both with identical competence. It is common for young simultaneous bilinguals to be more proficient in one language than the other, and this is probably related to each child's relative exposure to each language; for example, many bilingual children are more proficient in the mother's than the father's language, arguably because their mothers assume most of the childcare responsibilities and/or simply spend more time with their children. The dominant language is almost always the language spoken by the greatest number of the people the child interacts with (generally the language they are educated in). The child sees this language as more effective and begins to favor it. Research has suggested that a child's language dominance can shift over time due to the change in their language environment. There are multiple ways to measure the language dominance of a simultaneous bilingual child. Researchers approaching dominance as "relative language proficiency" adopt measures such as mean length of utterance (MLU), such as the child’s language input and output. Some studies have suggested that the measurement choice should be guided by the purpose of investigation because there is no single ‘best’ measure that suits all groups and purposes. There are also studies focusing on bilingual children's inter sentential code switching behaviour.

Code switching has also been tied to the bilingual child's socialization process. According to Poplack, a bilingual child code switches based on the perceived linguistic norms of the situation and the perceived bilingual ability of the hearer.

Children will mirror their parents in this aspect of speech. If a child's parents engage in code switching in their own speech, this will affect the child's perception of the appropriateness of mixing languages.

Whether and how a child's code switching behaviour is shaped by their language dominance is a controversial issue. Simultaneous trilingualism is also possible. There is significantly less research in this area than in simultaneous bilingualism. However, trilingual language acquisition in young children has been shown to generally mirror bilingual acquisition.