Shorter headed dogs, visually cooperative breeds, younger and playful dogs form eye contact faster with an unfamiliar human

Forming eye contact is important in dog–human communication. In this study we measured what factors affect dogs’ propensity for forming eye contact with an experimenter. We investigated the effect of [1] cephalic index (head shape’s metric, indicator of higher visual acuity at the centre of the visual field), [2] breed function (visual cooperativeness), [3] age and [4] playfulness with strangers in 125 companion dogs. Cephalic index was measured individually and analysed as a continuous variable. Results showed that [1] dogs with a higher cephalic index (shorter head) established eye contact faster. Since cephalic index is highly variable even within a breed, using artificial head shape groups or breed average cephalic index values is not recommended. [2] Breed function also affected dogs’ performance: cooperative breeds and mongrels established eye contact faster than dogs from non-cooperative breeds. [3] Younger dogs formed eye contact faster than older ones. [4] More playful dogs formed eye contact faster. Our results suggest that several factors affect dogs’ interspecific attention, and therefore their visual communication ability.