Early research that relied on standardized assessments of intelligence reported negative effects of bilingualism for children, but a study by Peal and Lambert (1962) reported better performance by bilingual than monolingual children on verbal and nonverbal intelligence tests. Ellen Bialystok discusses results, which are different from those reported by Peal and Lambert, used to reinterpret their findings in terms of the sociolinguistic, political, and cultural context in which the Peal and Lambert study was conducted and the relevance of those factors for all developmental research.  Read the Study