Vocabulary as a Central Link between Phonological Working Memory and Narrative Competence: Evidence from Monolingual and Bilingual Four-Year-Olds from Different Socioeconomic Backgrounds

Phonological working memory capacity, vocabulary size, and narrative competence are important skills in children's L1 and L2 acquisition, which may vary as a function of their language background and socioeconomic status (SES). We investigated test data of 56 typically developing 4-year-old kindergarten children from two SES and two language backgrounds: 29 children (15 higher SES, 14 lower SES) were monolingual German-speaking, and 27 children (14 higher SES, 13 lower SES) were successive Turkish-German bilinguals. The tests comprised a non-word repetition task testing phonological working memory, receptive vocabulary tests (in L1 and L2), and a narrative task. We investigated the effects of SES and language background on children's test performance. Results indicate that SES was a highly significant factor for phonological working memory and vocabulary in the monolingual children, but not in the bilingual children. Although the items of the non-word repetition task followed German phonotactic structure, lower SES (LSES) L2 children did not differ significantly from their monolingual LSES peers, demonstrating that there was no bilingual working memory disadvantage in the LSES group. A significant effect of language background was found for German vocabulary and for all categories of narrative competence, but only two slight SES effects on narrative competence. Significant correlations were found between phonological working memory and vocabulary as well as between vocabulary and narrative competence, but not between phonological working memory and narrative competence. Results suggest that phonological working memory and narrative competence are different domains of language awareness, and that vocabulary may act as the central variable mediating between them.