The semantics of talking with the eyes and gestures: the hormonal and cognitive underpinnings of comprehending cooperative communication in domestic dogs and wolves (WWTF CS11-026)
Zsófia Virányi, Friederike Range, Zsolt Rónai
Human communication is unique because it strongly relies on language as well as on the exceptional motivation of humans to share information with others. Identifying by means of words what someone is talking about is hardly available for non-human animals, but human as well as non-human animals can use the direction of others’ gaze and gestures to detect to which object or social partner others’ behaviour is referring to.
Hence, following others’ gaze and gestures has been suggested to be an evolutionary and developmental precursor of linguistic referential communication.
While several animal species have been shown to be able to detect third entities in the environment by following others’ gaze, it is questionable whether they recognize if their partners have communicative and information sharing motivations. This is apparent, for instance, in the failure of chimpanzees to choose one of two hiding places that has been indicated to contain some food by a cooperative human or conspecific looking at or pointing to the baited location, despite of the well-developed skills of these animals to locate objects along the line of others’ gaze in competitive situations.
Domestic dogs, however, show more human-like performance in this task. Consequently, it has been suggested that during the course of domestication dogs have evolved analogous skills of increased cooperativeness of humans. We argue, however, that this is a premature conclusion because no firm evidence shows that the success of dogs relies on the same mechanisms used by humans, and because our recent results have shown that also wolves, the closest undomesticated relatives of dogs can locate hidden food based on conspecific- and human-given cues if, instead of a human-specific hand gesture, a more species-typical cue (gaze) is used to indicate where the food can be found.
Accordingly, the overall objective of the proposed project is to critically investigate the phylogeny of following gaze and pointing as a nonverbal form of cooperative, referential and intentional communication. In order to achieve this objective, we will investigate whether, similarly to humans, puppies, adult pet dogs, pack-living dogs and pack-living wolves show attentional preferences to those body-parts and facial regions of conspecifics and humans that are crucial for communication (e.g. eyes, mouth, hands). In order to gain exact measurements, we will use an eye-tracker for this purpose. We will also examine whether fear-related motivations limit the attention dogs and wolves pay to human faces and human hands in comparison to other body parts of humans and to conspecific faces.