Gesturing towards the future: cognition, big data, and the future of comparative gesture research.

The field of ape gesture research has grown significantly in the past two decades, but progress on the question of gesture development has been limited by methodological and terminological disagreements, small sample sizes, and a lack of fine-grained longitudinal data. The main theories of gesture acquisition are often portrayed as mutually exclusive, but only some theories actually detail learning mechanisms, and differences in the level of analysis may help explain some of the apparent disagreements. Gesture research would benefit greatly from the articulation of more testable hypotheses. We propose two hypotheses that follow from dominant theories of gesture acquisition. We urge scholars to collect new data and leverage existing data in ways that maximize the potential for comparison across datasets and articulation with studies of other communicative modalities. Finally, we advocate for a transition away from using intentionality as a marker of the 'special status' of gesture, and towards using gesture as a window onto the lives and minds of apes.