Dogs fail to recognize a human pointing gesture in two-dimensional depictions of motion cues

Few studies have investigated biological motion perception in dogs and it remains unknown whether dogs recognise the biological identity of two-dimensional animations of human motion cues. To test this, we assessed the dogs’ (N=32) responses to pointlight displays of a human performing a pointing gesture towards one of two pots. At the start of the experiment the demonstrator was a real-life person, but over the course ofthe test dogs were presented with two-dimensional figurative representations of pointing gestures in which visual information was progressively removed until only the isolated motion cues remained. Dogs’ accuracy was above chance level only with reallife and black-and-white videos, but not with the silhouette or the point-light figure. Dogs’ accuracy during these conditions was significantly lower than in the real-life condition. This result could not be explained by trial order since dogs’ performance was still not higher than chance when only the point-light figure condition was presented after the initial demonstration. The results imply that dogs are unable to recognise humans in two-dimensional depictions of human motion cues only. In spite of extensive exposure to human movement, dogs need more perceptual cues to detect equivalence between human two-dimensional animations and the represented living entity.