How do children view and categorise human and dog facial expressions?

Children are often surrounded by other humans and companion animals (e.g., dogs, cats); and understanding facial expressions in all these social partners may be critical to successful social interactions. In an eye-tracking study, we examined how children (4-10 years old) view and label facial expressions in adult humans and dogs. We found that children looked more at dogs than humans, and more at negative than positive or neutral human expressions. Their viewing patterns (Proportion of Viewing Time, PVT) at individual facial regions were also modified by the viewed species and emotion, with the eyes not always being most viewed: this related to positive anticipation when viewing humans, whilst when viewing dogs, the mouth was viewed more or equally compared to the eyes for all emotions. We further found that children's labelling (Emotion Categorisation Accuracy, ECA) was better for the perceived valence than for emotion category, with positive human expressions easier than both positive and negative dog expressions. They performed poorly when asked to freely label facial expressions, but performed better for human than dog expressions. Finally, we found some effects of age, sex, and other factors (e.g., experience with dogs) on both PVT and ECA. Our study shows that children have a different gaze pattern and identification accuracy compared to adults, for viewing faces of human adults and dogs. We suggest that for recognising human (own-face-type) expressions, familiarity obtained through casual social interactions may be sufficient; but for recognising dog (other-face-type) expressions, explicit training may be required to develop competence. HIGHLIGHTS: We conducted an eye-tracking experiment to investigate how children view and categorise facial expressions in adult humans and dogs Children's viewing patterns were significantly dependent upon the facial region, species, and emotion viewed Children's categorisation also varied with the species and emotion viewed, with better performance for valence than emotion categories Own-face-types (adult humans) are easier than other-face-types (dogs) for children, and casual familiarity (e.g., through family dogs) to the latter is not enough to achieve perceptual competence.