Meta-analysis of Bilingualism Cognitive-Academic Outcomes

Bilingualism is a familiar and widespread issue in current societies, particularly in Iran that has its own special educational effects according to study results. The purpose of this study was to determine the combined effect size of bilingualism cognitive-academic outcomes based on studies conducted in Iran through a meta-analytic procedure. In this study, the statistical population is concerned the available studies related to bilingualism cognitive-academic outcomes. Finally, considering inclusion and exclusion criteria, quantitative results of 21 studies were analyzed. The combination of difference effect sizes between bilingual and monolingual learners showed that overall, compared with monolingual learners, bilingual ones were weaker in terms of cognitive (ES=-.27). This difference was observed in more than two-thirds of the primary study effect sizes. However, more detailed analysis revealed that there were significant differences between the two groups in academic indicators (ES =-.36) and about basic cognitive indicators such as intelligence, no significant differences were observed between the two groups (ES=-.10). Also, additional analysis showed that the greatest difference between the bilingual and monolingual subjects was in writing and reading than in math and science. Other findings revealed that type of language in bilingual learners could influence difference effect size indicators between monolingual and bilingual people.