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Referential gestures such as pointing are ubiquitous in human societies and the production and comprehension of referential gestures requires many of the cognitive capacities also crucial for language, including reading intentions and establishing common ground (Tomasello 2008). Given the importance of referential gesturing in human communication, there has been significant debate over the evolutionary origins of this behavior. Although captive and enculturated chimpanzees spontaneously learn to point referentially for human caregivers (Leavens et al., 2004), habitual use of referential gestures was thought to be absent in wild chimpanzees, until Pika and Mitani (2006) reported the use of ‘directed scratches’ during grooming bouts amongst male dyads in the Ngogo community of chimpanzees. In this community, after the recipient of grooming scratched his own body, in 64% of cases, the groomer then groomed the scratched location. Pika and Mitani concluded that wild chimpanzees use gestures to specify where they want to be groomed and that these scratch gestures were both referential and iconic. In an attempt to replicate and extend these findings we recorded dyadic grooming bouts in the Kanyawara and Sonso communities of chimpanzees, located approximately 10 and 200km from the Ngogo community in Uganda. Grooming interactions were filmed and we coded all instances of ‘big loud scratches’ and ‘present body part’ gestures (where a body part is moved towards the groomer possibly to request grooming in that broad body area), of which only the former has been argued to be referential. We identified all scratches given by recipients of grooming and coded whether the groomer groomed within 5cm of the scratched location in the 10 seconds after the scratch ended. In cases where the groomer did not begin grooming in the scratched location, we then examined 467

Referential gestures are not ubiquitous in wild chimpanzee communities