The Value of Non-Referential Gestures: A Systematic Review of Their Cognitive and Linguistic Effects in Children's Language Development.

Speakers produce both referential gestures, which depict properties of a referent, and non-referential gestures, which lack semantic content. While a large number of studies have demonstrated the cognitive and linguistic benefits of referential gestures as well as their precursor and predictive role in both typically developing (TD) and non-TD children, less is known about non-referential gestures in cognitive and complex linguistic domains, such as narrative development. This paper is a systematic review and narrative synthesis of the research concerned with assessing the effects of non-referential gestures in such domains. A search of the literature turned up 11 studies, collectively involving 898 2- to 8-year-old TD children. Although they yielded contradictory evidence, pointing to the need for further investigations, the results of the six studies-in which experimental tasks and materials were pragmatically based-revealed that non-referential gestures not only enhance information recall and narrative comprehension but also act as predictors and causal mechanisms for narrative performance. This suggests that their bootstrapping role in language development is due to the fact that they have important discourse-pragmatic functions that help frame discourse. These findings should be of particular interest to teachers and future studies could extend their impact to non-TD children.