Dog's gaze following is tuned to human communicative signals
Recent evidence suggests that preverbal infants’ gaze following can be triggered only if an actor’s head turn is preceded by the expression of communicative intent. Such connectedness between ostensive and referential signals may be uniquely human, enabling infants to effectively respond to referential communication directed to them. In the light of increasing evidence of dogs’ social communicative skills, an intriguing question is whether dogs’ responsiveness to human directional gestures is associated with the situational context in an infant-like manner. Borrowing a method used in infant studies, dogs watched video presentations of a human actor turning toward one of two objects, and their eye-gaze patterns were recorded with an eye tracker. Results show a higher tendency of gaze following in dogs when the human’s head turning was preceded by the expression of communicative intent (direct gaze, addressing). This is the first evidence to show that (1) eye-tracking techniques can be used for studying dogs’ social skills and (2) the exploitation of human gaze cues depends on the communicatively relevant pattern of ostensive and referential signals in dogs. Our findings give further support to the existence of a functionally infant-analog social competence in this species.
Differential sensitivity to human communication in dogs, wolves and human infants
Ten-month-old infants search for a hidden object persistently at its initial hiding place even after observing it being hidden at another location. Recent evidence suggests that communicative cues from the experimenter contribute to the emergence of this perseverative search error. Here we replicate these results with dogs, who also commit more search errors in ostensive-communicative (in 75% of the total trials) than in non-communicative (39%) or non-social (17%) hiding contexts. However, comparative investigations suggest that communicative signals serve different functions for dogs and infants, while human-reared wolves do not show dog-like context-dependent differences of search errors. We propose that shared sensitivity to human communicative signals stems from convergent social evolution of the Homo and the Canis genera.