Reading emotions in Dogs' eyes and Dogs' faces

Our primary goal was to investigate human ability to recognize basic emotions from only the eyes of dogs in comparison to the whole face. Simultaneously, we replicated and extended previous research (Bloom et al., 2021), while validating American canine emotional facial expression photographs cross-culturally to Brazil. Participants (N = 120) viewed behaviorally-anchored photographs of three breeds. Half the participants in each condition (faces or eyes-only) viewed two-word forced choice items while the other half viewed four-word forced choice items. Participants identified target emotions from images of both dogs' faces and eyes-only at a higher rate than chance. Fear was accurately recognized more than the other emotions. When dogs are afraid, they open their eyes and expose the sclera, a conspicuous signal. Emotion identification accuracy was highest for the Rhodesian Ridgeback, who is similar in morphology to common Brazilian stray dogs (Vira-Latas Carmelo). We conjectured that Brazilians were more accustomed to seeing dogs with the Rhodesian Ridgeback morphology than the erect-eared breeds, thus increasing accuracy for this breed. Further studies with additional dog morphologies are desirable. In addition to research interest, our Canine Eyes task has the potential to become a test of individual differences in Theory of Mind with clinical applications.