The chapters in the handbook cover five main topics. Gesture types in terms of forms and functions; the focus is on manual gestures and their use as emblems, recurrent gestures, pointing gestures, and iconic representational gestures, but attention is also given to facial gestures. Different methods by which gestures have been annotated and analyzed, and different theoretical and methodological approaches, including semiotic analysis. The relation of gesture to language use covers language evolution as well as first and second language acquisition. Gestures in relation to cognition, including an overview of McNeill’s growth point theory. Gestures in interaction, considering variation in gesture use and intersubjectivity. Across the chapters, the meaning of the term ‘gesture’ is itself debated, as is the relation of gesture to language (as multimodal communication or in terms of different semiotic systems). Gesture use is studied based on data from speakers of various languages and cultures, but there is a bias toward European cultures, which remains to be addressed. The handbook provides overviews of the work of some scholars which was previously not widely available in English.

Proposals that gesture played a pivotal role in the evolution of language have been highly influential. However, there are many differences between gestural origin theories, including different definitions of ‘gesture’ itself. We use a cognitive semiotic approach in order to categorize and review these theories. A semiotic system is a combination of signs or signals of particular type, defined by characteristic properties, and the interrelations between these signs/signals. Signal systems like spontaneous facial expressions and non-linguistic vocalizations are under less voluntary control than sign systems. The basic distinction relates to the question of whether gesture played an exclusive role in early stages of language evolution (monosemiotic theories), or whether other semiotic systems were involved as well: polysemiotic theories. The latter may be equipollent, where language and gesture are considered equally prominent from the onset, or pantomimic, where gesture played the main but not exclusive role in breaking from predominantly signal-based to sign-based communication. We conclude that pantomimic theories are the most promising kind.