Cognition and bilingualism: a reanalysis of studies

Abstract

Much of recent literature on bilingualism and cognitive development has claimed that bilingualism causes cognitive enhancement. This paper reviews the methodology of these studies and concludes that these, primarily associational', studies do not support this conclusion. A more parsimonious explanation of differences between bilinguals and unilinguals is to be found in differences in self-selection of children in non-compulsory second language learning environments and in difficulties of access to learning and social stress which affect minority language children who are forced to learn the majority language in ways that are very much like the difficulties of lower class children where language is not an issue.The 1962 Peal and Lambert study seems to have marked a watershed in research into the relation between bilingualism and various cognitive skills (Cummins, 1976b(Cummins, , 1978. Before that, the weight of research evidence tended to support a negative association. That is, comparisons of groups of unilingual and bilingual children on various verbal and nonverbal intelligence measures indicated some superiority for the unilinguals more often than not. Although some current research still supports the negative association, the trend of the evidence has swung to favour the bilingual children. Among research done in a Canadian setting, I have found no recent work which puts unilinguals ahead of or equal to their bilingual peers.This paper attempts to account for this shift in results and to examine the claim that there is a 'causal link between bilingualism and (cognitive) flexibility, the former apparently enhancing the latter' (Lambert, 1978: 539). The review of the literature will consider first the research designs and the results. Next, the dependent, cognitive measures will be discussed and then sample selection and the operationalization of Linguistics 17 (1979), 231-255.

The effects of early bilingual schooling on first language skills

“…It should be cautioned, however, that despite its longitudinal nature, the design of this study remains "quasiexperimental" in that students in our sample were not in the first place randomly assigned to immersion or regular program treatments (immersion is an optional alternative to the regular program). There can thus be no firm guarantee that the groups are entirely comparable on factors which could not be controlled for in the present study (MacNab, 1979).…”

“…Unfortunately many studies investigating the "effects" of bilingualism, including quite recent ones, have been unable to control for initial cognitive (or other) differences between the bilingual subjects and their monolingual comparisons (e.g., studies reviewed by Darcy, 1953;Peal & Lambert, 1962;Balkan, 1970;Bain & Yu, 1978). This has made it impossible to determine whether the advantages or disadvantages found in association with bilingualism were actually caused by bilingualism or were due to other alreadyexisting differences between the groups being compared (MacNab, 1979). The need for new in-depth longitudinal studies of the relationship between bilingualism and cognitive functioning has been stressed (e.g., Hakuta, 1980).…”

Bilingualism and Cognitive Development

“…In general, these studies show superior performance of bilinguals on the various dependent measures of cognitive ability. However, cause-effect relationships have not been established since they are cross-sectional and, furthermore, assignment to conditions is not random (McNab 1979).…”

New Methodologies for Studying the Relationship of Bilingualism and Cognitive Flexibility

“…But there are actually some profound methodological difficulties in the standard design, some of which were pointed out quite early by John Macnamara (1966). More recently, MacNab (1979) has forcefully criticized the inferences drawn from the studies, given their methodology (also Hakuta and Diaz [in press] develop an independent but similar line of argument). The difficulties need to be addressed, even if the results agree with our biases.…”

“…It could just as easily be the other way around, that children who are more "cognitively flexible" become bilingual. Indeed, the results from the longitudinal studies that are available are ambiguous (see review by MacNab 1979) .…”