Proceedings of the Annual Meeting of the Cognitive Science Society

This study examined the developmental trajectory of supplementary gestures, which conveyed information distinct from speech, and their semantic relationships with accompanying speech in 16 Mandarin-speaking children. Children were observed during mother–child interactions between 12 and 21 months of age at three-month intervals, with minimal age variation within each time point. Findings showed a marked increase in supplementary gestures at 18 months, alongside the predominance of declarative pointing within gesture-speech acts and one-word utterances. This specific cross-modal pattern remained stable through 21 months. Most cross modal combinations conveyed entity ideas, with predicative ideas occurring infrequently and propositional ideas even less often. The common 'entity-related', 'what is done to what', and 'who initiates what and who/what is affected' knowledge was linguistically expressed only about three to six months later than in gesture-speech acts. Overall, the findings support the enduring role of supplementary gestures in enriching children's communicative expressiveness within a single act.