Keywords: bilingual advantage, bilingual lexicon, exposure to input, vocabulary size.
We address two questions of interest for bilingual research: whether the assumed lesser input in each of the respective languages affects negatively the early bilingual receptive lexicon, and whether other factors in the environment affect positively vocabulary growth. We report a study designed to establish for the first time the size of the early lexicon of bilingual and monolingual speakers of Russian and Kazakh in Kazakhstan. We demonstrate that bilingualism is not disadvantageous for early lexical development: both bilingual groups perform better than age-matched monolinguals on receptive vocabulary tasks. We attribute these results to enhanced conditions: increased exposure to both languages through immersion and societal language practice, and better quality of input through structured education.