Second language acquisition of American Sign Language influences co-speech gesture production.

Previous work indicates that 1) adults with native sign language experience produce more manual co-speech gestures than monolingual non-signers, and 2) one year of ASL instruction increases gesture production in adults, but not enough to differentiate them from non-signers. To elucidate these effects, we asked early ASL-English bilinguals, fluent late second language (L2) signers (≥ 10 years of experience signing), and monolingual non-signers to retell a story depicted in cartoon clips to a monolingual partner. Early and L2 signers produced manual gestures at higher rates compared to non-signers, particularly iconic gestures, and used a greater variety of handshapes.