Sex, skull length, breed, and age predict how dogs look at faces of humans and conspecifics
The gaze of other dogs and humans is informative for dogs, but it has not been explored which factors predict face-directed attention. We used image presentations of unfamiliar human and dog heads, facing the observer (portrait) or facing away (profile), and measured looking time responses. We expected dog portraits to be aversive, human portraits to attract interest, and tested dogs of different sex, skull length and breed function, which in previous work had predicted human-directed attention. Dog portraits attracted longer looking times than human profiles. Mesocephalic dogs looked at portraits longer than at profiles, independent of the species in the image. Overall, brachycephalic dogs and dogs of unspecified breed function (such as mixed breeds) displayed the longest looking times. Among the latter, females observed the images for longer than males, which is in line with human findings on sex differences in processing faces. In a subsequent experiment, we tested whether dog portraits functioned as threatening stimuli. We hypothesized that dogs will avoid food rewards or approach them more slowly in the presence of a dog portrait, but found no effect of image type. In general, older dogs took longer to approach food placed in front of the images and mesocephalic dogs were faster than dogs of other skull length types. The results suggest that short-headed dogs are more attentive to faces, while sex and breed function predict looking times through complex interactions.
KeywordsGaze following Perception Breed differences Dog cognition
The authors would like to thank Flóra Szánthó, Tamás Faragó, Fanni Tompai and Antal Dóka for assistance in the laboratory, Borbála Turcsán, Lisa Wallis and Patrizia Piotti for statistical consultancy, Kauê Machado Costa for useful comments on the manuscript and editing, József Topál, Dóra Szabó, Fanni Lehoczki for general consultancy, Ákos Árokszállási for the randomization script and the owners of the dogs for their time and assistance.
ZB contributed to experimental design, data collection, explorative analysis; IBI helped in writing, final analysis; EK was involved in experimental design, explorative analysis, writing.
This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 680040) and from the Bolyai Foundation of the Hungarian Academy of Sciences.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This study on dogs complies with the current laws of Hungary. According to the corresponding definition by law (‘1998. évi XXVIII. Törvény’ 3. §/9.—the Animal Protection Act), non-invasive studies on dogs are currently allowed to be done without any special permission in Hungary. We confirm that the procedures comply with national and EU legislation. Owners provided written consent to their participation. Our Consent Form was based on the Ethical Codex of the Hungarian Psychologists (2004).
Dogs respond with social behaviours towards dog portraits. Shown in this sequence, examples of barking, growling, averted gaze, yawning, explorative sniffing. Video abstract: https://www.youtube.com/watch?v=pS5j8TMrDZE&feature=youtu.be (MP4 17858 kb)
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