It may be the amount of exposure to each language that is the factor for whether or not a bilingual child develops similarly to a monolingual child in each of those languages. Research has shown that children who are exposed less to a language will have "significantly lower receptive vocabulary scores for" that language. By contrast, the receptive vocabulary of bilingual children does not appear to be different from that of monolingual children when 40% to 60% of their language exposure is to that language. Vocabulary size in each language appears to be affected by both the "frequency of exposure" and the "differences in context of exposure" to that language. Varying contexts of exposure provide more opportunities for bilingual children to learn more words. Bilinguals who are exposed to more of one language than another will perform similarly on tasks to monolinguals of that language, but they will lag behind in vocabulary of the other language.