The Relationship Between Degree of Bilingualism and Cognitive Ability : A Critical Discussion and Some New Longitudinal Data

In 1962, Elizabeth Peal and Wallace Lambert of McGill University published a monograph entitled “The Relation of Bilingualism to Intelligence.”The research, conducted in Montreal with 10-year-old children, compared the performance of monolinguals t o that of bilingual, French/English-speaking subjects on a variety of standard tests of intelligence. In contrast to previous research on bilingualism and intelligence, Peal and Lambert (1962) discov, ered that their bilingual sample showed superior performance on measures of verbal intelligence and on nonverbal tests “involving concept-formation or symbolic flexibility Ip. 141.” What differentiated the study from its ancestral relatives was the care with which Peal and Lambert exercised control over sample selection. They drew a distinction between true, “balanced bilinguals” who are proficient in both their first (11) and second language (L2) and “pseudo-bilinguals” who, for various reasons, have not yet attained ageappropriate abilities in their second language. According to Peal and Lambert(l962): “The pseudo-bilingual knows one language much better than the other, and does not use his second language in communication. The true (or balanced) bilingual masters both at an early age and has facility with both as means of communication [p. 61.” Into their sample of bilinguals, only those considered “balanced” were admitted. Peal and Lambert’s study had substantial impact on two fronts. First, it raised the consciousness of researchers on the problem of selecting appropri320 HAKUTA AND DIAZ