In this study, researchers compared 104 six-year-old children belonging to 4 groups (English monolinguals, Chinese-English bilinguals, French-English bilinguals, Spanish-English bilinguals) on a series of tasks in order to determine the effect of bilingualism on development. Taking into account language, cultural background, and the language of schooling, researchers examined the outcomes of language tasks and cognitive tasks across the groups. They found that bilingualism had a positive effect on executive control tasks, but that the performance on the language task varied depending on educational experience and the similarity between the two languages.
Barac, R. & Bialystok, E. (2012). Bilingual Effects on Cognitive and Linguistic Development: Role of Language, Cultural Background, and Education. Child Development.