Contextualized bilingualism among adolescents from four different ethnic groups in Indonesia

Aims and objectives: We were interested in group differences in Indonesia in bilingualism, whether vocabulary knowledge shows a differential pattern across the languages, and whether language skill and usage differences between groups are moderated by contextual factors, such as ethnic group size. Data and analysis: We examined group differences in language usage at home and in public, self-reported proficiency, and vocabulary scores in both languages among 632 adolescents (292 males, M-age = 14.57 years) from four ethnic groups in Indonesia (214 Javanese, 115 Batak Toba, 108 Toraja, and 195 Chinese). Differential item functioning analysis was conducted to test whether adolescents had different vocabulary they only know in one language, which would indicate equality or inequality in access to knowledge in the two languages. Findings: There were large differences in language knowledge and usage. The lowest scores in ethnic language vocabulary and usage were found among the Chinese group. Across groups, scores for Bahasa Indonesia (L2) vocabulary were higher than ethnic language (L1) vocabulary. However, the ranking from easy to difficult words was similar across the languages and there were no specific sets of items that were differentially known in any language. Originality: We investigated bilingualism among non-immigrant adolescents in an under-researched, non-WEIRD (western, educated, industrialized, rich, democratic) society. The study shows the role of language usage and skill that is different from a western context in various aspects, such as the dominance of L2 in all groups.