Zehra Ongun and Michael Daller Bilingualism, Vocabulary size and IQ Scores: The case of Turkish-English bilingual children in the UK Zehra Ongun and Michael Daller University of Reading 2016 m.daller@reading.ac.uk z.ongun@pgr.reading.ac.uk Abstract Results Results Methodology This study aims to investigate the relationship between the vocabulary knowledge of bilingual children in both of their languages (L1: Turkish, L2: English) and the relation of non-verbal intelligence scores and vocabulary knowledge. In addition, the study explores the role of parental language dominance preferences on the vocabulary knowledge and IQ level of bilingual children specifically. One theoretical framework for the relation between L1 and L2 of bilinguals is Cummin’s Common Underlying Proficiency CUP (1980, 1991). Figure 1 Receptive vocabulary development in both languages of the bilingual children by AGE Figure2, 3 Correlations of language dominance of parents and receptive vocabulary scores of children in English and Turkish Results Results Participants 100 Turkish- English bilingual children from middle-class Turkish immigrant families (all born in the UK, age between 7-11) at least one parent has a university degree Measures: Receptive vocabulary tests in both languages (X-lex, Meara & Milton, 2003) A non- verbal intelligence test (Raven’s colored matrices, 1997) The Language Dominance Scale (Dunn and Fox Tree, 2009) Correlations between Receptive vocabulary knowledge in both languages and non-verbal Intelligence Partial correlations controlling by AGE IQ and Turkish vocab (r = .263, p < .01) IQ and English vocab(r = .206, p < .05) Figure4 Parents` language dominance and children`s intelligence scores Conclusion The results indicate a strong positive correlation between vocabulary knowledge in both languages of bilingual children. The results also show that non-verbal intelligence and vocabulary knowledge are related. Parental minority language support in an immigration setting (Turkish in this case) has a positive effect on vocabulary knowledge in both languages and on non-verbal intelligence. References Cummins, J. (1980). The construct of Language proficiency in bilingual education. In: Colin Baker. Foundation of Bilingual Education and Bilingualism. Clevedon: Multilingual Matters Cummins, J. (1991). Interdependence of first- and second-language proficiency in bilingual children. In: Bialystok, E. (1991). Language processing in bilingual children, pp. 70-89. Cambridge: Cambridge University Press. 3. Dunn, A.L. and Fox-Tree (2009). A quick, gradient Bilingual Dominance Scale. Bilingualism: Language and Cognition, 12(3), 273-289. 4. Meara, P. and Milton, J. (2003). X-Lex. The Swansea Levels Test. Newbury: Express Publishing. 5. Raven, J.C. (1997) Coloured Progressive Matrices . Los Angeles: Western Psychological Services.