Morphological Differences Between Imperative and Declarative Pointing: Hand Shape, Arm Extension, and Body Posture

Abstract

ABSTRACT. The authors used frame-by-frame video analyses to describe the features of imperative and declarative pointing gestures produced by young children, in comparison to reaching actions. First, the results showed that imperative pointing shared common features with reaching actions (hand shape, arm extension), but body posture observed in reaching differed from the one observed in pointing, both in imperative and declarative contexts. Second, hand shape was influenced by precision constraints: imperative gestures shifted from whole-hand pointing to index-finger pointing when the target was surrounded by distractors. This study is the first of its kind to highlight the effect of several variables on morphological features of pointing using quantitative measures and may provide insights into the nature of imperative and declarative pointing.

Keywords:

• arm extension
• body posture
• gestural communication
• hand shape
• imperative and declarative pointing
• reaching