Gesture and speech form a tightly integrated system in first language (L1). We know less about the gesture-speech system in second language (L2) production, particularly with respect to speaker proficiency and discourse context. In this study, we focused on the speech and gestures produced by adult Persian (L1)-English (L2) bilinguals with high or low L2 proficiency and English native speakers (n = 22/group). We asked whether speaker proficiency (native, high, low) and discourse context (narratives, explanations) influence the amount, diversity and complexity of speech and gesture production. Our results showed an effect of context, with greater production of speech and gesture in narratives than explanations across proficiency levels. More importantly, we found an effect of proficiency – with lower speech complexity coupled with greater gesture complexity in bilinguals with low proficiency, particularly in the explanation context – suggesting a compensatory role for gesture among bilinguals with low L2 proficiency in more demanding communicative contexts.
