Priming beyond syntax: Crosslinguistic evidence for shared syntactic and thematic representations in Polish-English bilingual children

Within- and cross-language syntactic priming in bilingual adults, and increasingly in children, offers compelling evidence for shared representations across languages. However, little is known about whether such shared representations extend beyond syntax to other structural levels, or how they develop during childhood. We addressed this limitation in three experiments with Polish-English bilingual children aged 7;11–12;4 ( N = 96), and adults ( N = 45). We investigated bidirectional priming both across languages (children and adults) and within languages (children only) for transitive structures that contrasted in whether they had shared syntactic structure (passive primes/passive targets) or shared thematic role orders (OVS primes/passive targets) in English and Polish (N items = 48/language). We found significant priming of syntactic structures (speakers produced more passives after passive than active primes) in both languages and significant priming of thematic role order (speakers produced more passives after OVS than active primes) from Polish to English. For children, these effects were stronger within languages than across languages, and cross-linguistic priming was only significant when English, the societal language, was the target language. For adults, these effects did not differ by target language, and priming was stronger than in children. These results provide an important picture of the developmental trajectory of shared representations at the level of syntactic structure and thematic roles: bilingual children acquire robust within-language representations for each language, while shared representations develop later and appear entrenched within adult bilingual speakers. The emergence of shared representations reflects asymmetrical language experience, manifesting in stronger priming for the children's societal language than for their heritage language.