How early do children understand gesture-speech combinations with iconic gestures?

Children understand gesture+speech combinations in which a deictic gesture adds new information to the accompanying speech by age 1;6 (Morford & Goldin-Meadow, 1992; 'push'+point at ball). This study explores how early children understand gesture+speech combinations in which an iconic gesture conveys additional information not found in the accompanying speech (e.g., 'read'+BOOK gesture). Our analysis of two- to four-year-old children's responses in a gesture+speech comprehension task showed that children grasp the meaning of iconic co-speech gestures by age three and continue to improve their understanding with age. Overall, our study highlights the important role gesture plays in language comprehension as children learn to unpack increasingly complex communications addressed to them at the early ages.