Donald Duck's garden: The effects of observing iconic reinforcing and contradictory gestures on narrative comprehension.

Both speech and gesture play a vital role in human communication. Gesture itself provides an external support to a spoken message. As a consequence, when presented together with speech, gesture has the ability to benefit learning across a variety of tasks, including narrative comprehension. However, the exact mechanisms underlying how the observation of gestures benefits learning are yet to be well understood and cannot be understood without further investigation into the types of gesture that benefit learning. Specifically, gestures themselves are not a homogeneous set, with different kinds of gestures having varying effects on learning. In the current study, we examined the effects of observing iconic gestures that either reinforce (i.e., reinforcing gestures) or contradict (i.e., contradictory gestures) the content of accompanying speech on narrative comprehension in preschool-aged children. Children were presented with a short video narrative that contained either reinforcing gestures, contradictory gestures, or no gestures accompanying the verbal narrative. Results indicated that observing reinforcing gestures significantly benefited narrative comprehension beyond when no gestures were observed. However, observing contradictory gestures was neither significantly beneficial nor significantly detrimental to narrative comprehension beyond observing reinforcing or no gestures. The results from the current study provide valuable insight into the benefits of observing different kinds of iconic gestures on narrative comprehension in preschool-aged children.