Early action and gesture "vocabulary" and its relation with word comprehension and production.

Data from 492 Italian infants (8-18 months) were collected with the parental questionnaire MacArthur Bates Communicative Development Inventories to describe early actions and gestures (A-G) "vocabulary" and its relation with spoken vocabulary in both comprehension and production. A-G were more strongly correlated with word comprehension than word production. A clear developmental pattern for the different types of A-G was found. These findings are similar to those of different Western languages, indicating a common biological and cultural basis. The analysis of individual A-G and their relations with early words with a related meaning showed interesting similarities between the production of A-G with and without object manipulation and the comprehension and production of corresponding words. Results indicate that the transition from A-G to spoken language is mediated by word comprehension.