Empirical evidence suggests that children who are bilingual are associated with increased meta-cognitive skills and greater divergent thinking ability. There are several evidence that is found about bilingual children is that they are better at performance on some perceptual tasks and classification tasks. Several studies believed that bilingual experience will enhance one’s ability to think more flexibly and abstractly about language. Bilingual children appeared to be two to three years ahead of monolinguals with regard to semantic development (Ianco-Worrall, 1972). One of the first to discuss the effects of bilingualism was Vygotsky. He claimed that the bilingual child is able “to see a language as one particular system among many, to view its phenomena under more general categories, and this leads to awareness of his linguistic operation.” (Vygotsky, 1978). Children who can understand and speak two languages may have a more developed understanding of language.
Furthermore, Werner Leopold (1949) claims that after exposing his daughter to a second language helped her enhance her mental development. He believed that children who are bilingual tend to focus on the content of the words rather than the forms of words and are forced to separate two different words for each referent. At McGill University in Montreal, Peal and Lambert (1962) conducted a study where they compare bilingual and monolingual children using intelligence tests and subtests. They found that bilingual children scored significantly higher than monolinguals on most aspects or verbal and nonverbal intelligence especially those tests that require mental manipulation and reorganization of visual symbols, concept formation, and symbolic flexibility. Peal and Lambert established that bilingual children were able to outperform the monolingual children because of their enhanced mental flexibility and strong concept formation skills.
Additionally, a study by Bialystok (1999) found that bilingual children and monolingual children had no difference in English proficiency, but bilinguals were more skilled than monolinguals when the tasks involved tasks that made the solution difficult. This study contained 60 preschool children, half of whom were bilingual. These children were given English proficiency tests and a test to see their working memory. The bilingual children were more advanced than the monolinguals in the solving of experimental problems requiring high levels of control. Recent studies and the studies above have shown that most bilingual children have better meta-linguistic awareness, classification skills, concept formation, analogical reasoning, visual-spatial skills, and semantic development.
Research appears to suggest a positive relationship between bilingualism and a wide range of other cognitive measures. Some of these tasks include superior performance on concept formation tasks, enhanced ability to restructure perceptual solutions (Bain, 1975). Others include stronger performances in rule discovery tasks, greater verbal ability and verbal intelligence, and higher levels of cognitive development at an earlier age reached by bilingual children than their monolingual peers (Hamayan, 1986).