Pointing gestures produced by toddlers from 15 to 30 months: different functions, hand shapes and laterality patterns.

Three experimental designs were implemented in day nurseries in order to elicit imperative, declarative expressive, and declarative informative pointing gestures (Tomasello, Carpenter, & Liszkowski, 2007) among a population of 48 toddlers aged 15-30 months. Several features were recorded for each situation, including gesture form, gaze direction, and vocalizations. A unimanual reaching task was also administered, in order to compare laterality patterns for each type of gesture. Main results revealed that imperative gestures were associated with whole-hand pointing, whereas declarative gestures were more frequently characterized by an extended index finger. Moreover, declarative gestures were more frequently accompanied by vocalizations than imperative gestures were. Finally, different degrees of manual preference were observed, especially for informative pointing gestures, which tended to be more right-handed than reaching actions. Results of the study are discussed in relation to the nature and development of each kind of pointing gesture.