Impact of Bilingual Education on Language and Cognitive Development in Children in Ebonyi State

This study examines the impact of bilingual education on language and cognitive development in primary school children in Ebonyi State, South East Nigeria. Nigeria's linguistic diversity has generated ongoing debate about the optimal medium of instruction in early primary education, with advocates of mother tongue instruction arguing for cognitive and cultural benefits while proponents of early English immersion emphasise communicative advantages. This study adopted a quasi-experimental design, comparing 320 children aged 5 to 9 years enrolled in Igbo-English bilingual classrooms with a matched group receiving English-only instruction across six schools in Abakaliki and Ishielu. Language proficiency was assessed in both Igbo and English using adapted assessments, and cognitive abilities were evaluated using the Raven's Coloured Progressive Matrices. Analysis of covariance and multivariate analysis of variance were applied, controlling for socioeconomic status and parental education. Results indicate that bilingual programme children demonstrated higher metalinguistic awareness, executive function scores, and comparable English proficiency to their English-only peers by Year 3. Mother tongue development was significantly stronger in the bilingual group with no trade-off in English acquisition rates. The study provides regionally specific evidence supporting bilingual education policy in Ebonyi State and recommends investment in Igbo language teaching materials and teacher language training programmes. Keywords: bilingual education, language development, cognitive development, Ebonyi State, mother tongue.