Co-speech gestures can interfere with learning foreign language words

Co-speech gestures can help the learning, processing, and memory of words and concepts, particularly motoric and spatial concepts such as verbs. The purpose of the present studies was to test whether co-speech gestures support the learning of words through gist traces of movement. We asked English monolinguals to learn 40 Cantonese words (20 verbs and 20 nouns). In two studies, we found support for the gist traces of congruent gestures being movement: participants who saw congruent gestures while hearing Cantonese words thought they had seen more verbs than participants in any other condition. However, gist traces were unrelated to the accurate recall of either nouns or verbs. In both studies, learning Cantonese words accompanied by congruent gestures tended to interfere with the learning of nouns (but not verbs). In Study 2, we ruled out the possibility that this interference was due either to gestures conveying representational information in another medium or to distraction from moving hands. We argue that gestures can interfere with learning foreign language words when they represent the referents (e.g., show shape or size) because learners must interpret the hands as something other than hands.