Understanding how dogs communicate with humans is essential as their roles in society continue to expand. This study examined whether facial phenotypes—including markings, coloration, and patterns—influence how expressive dogs are toward people. By applying the Dog Facial Action Coding System (DogFACS) and a newly developed framework for coding facial complexity, researchers analyzed 103 dogs across eight breed groups.
The results revealed a statistically significant but weak correlation between facial complexity and expressivity. Dogs with plainer, less marked faces exhibited higher rates of facial expression (r = −0.326, p ≤ 0.001). These dogs engaged more readily with human partners through clear muscle movements and facial cues, suggesting that simpler facial patterns may enhance communication.
Age and training also shaped expressivity. Adult dogs were more expressive than senior dogs, and highly trained or skilled dogs displayed more expressive behaviors than untrained companions. Notably, human caretakers accurately judged the expressivity of adult dogs with plainer faces, indicating that simpler facial patterns may improve perceptual clarity during interactions.
Within-subject analyses revealed that dogs distribute their facial muscle movements more evenly during highly social interactions compared to situations in which they receive ambiguous cues from their owners. This suggests that dogs modulate facial communication based on social context, highlighting the flexibility and nuance of canine expressive behavior.
These findings contribute to a deeper understanding of interspecies communication and have practical implications for training, welfare, and selection of working dogs. As humans and dogs continue to coexist closely, recognizing how facial morphology shapes expression offers new insights into strengthening the dog–human bond.
Source: Sexton, C., Buckley, C., Lieberfarb, J., Subiaul, F., Hecht, E., & Bradley, B. (2023). What Is Written on a Dog’s Face? Evaluating the Impact of Facial Phenotypes on Communication between Humans and Canines. Animals. Published July 1, 2023.
