Threatening faces evoke unique responses in dogs
The study utilized eye gaze tracking to demonstrate how dogs view the emotional expressions of dog and human faces. Dogs looked first at the eye region and generally examined eyes longer than nose or mouth areas. Species-specific characteristics of certain expressions attracted their attention, for example the mouths of threatening dogs. However, dogs appeared to base their perception of facial expressions on the whole face.
Threatening faces evoked attentional bias, which may be based on an evolutionary adaptive mechanism: the sensitivity to detect and avoid threats represents a survival advantage. Interestingly, dogs' viewing behavior was dependent on the depicted species: threatening conspecifics' faces evoked longer looking but threatening human faces instead an avoidance response. Threatening signals carrying different biological validity are most likely processed via distinctive neurocognitive pathways.
"The tolerant behavior strategy of dogs toward humans may partially explain the results. Domestication may have equipped dogs with a sensitivity to detect the threat signals of humans and respond them with pronounced appeasement signals," says researcher Sanni Somppi from the University of Helsinki.
Threatening faces