Levelling playing field: synchronization and rapid facial mimicry in dog-horse play.

This study investigates the social play behavior between dogs and horses, focusing on their ability to perceive and interpret each other’s signals. It was found that despite their size differences, phylogenetic distance, and different behavioral patterns, dogs and horses could synchronize their actions to reduce the possibility of misunderstanding and aggression.

Study Background and Method

• The researchers noted that inter-species play can shed light on a species’ cognitive and communicative abilities. While most studies in this area have focused on dog-human play, this research specifically focused on play between dogs and horses.
• To gather data, the researchers selected 20 videos of dog-horse play from YouTube using specific keywords. Each session in the selected videos had to be longer than 30 seconds.

Behavioral Patterns

• The researchers studied the behavioral patterns shown by dogs and horses during play, defining analogous (similar) and species-specific patterns.
• These patterns were used to analyze the rates of ‘self-handicapping’ and the variability in playful actions. Self-handicapping rates and playful action variability did not differ significantly between dogs and horses, indicating a balance in their playful tactics.

Mimicry Behaviours

• The Relaxed Open Mouth (ROM), a common playful face expression among mammals, was observed equally in both dogs and horses.
• The study also discussed the Rapid Facial Mimicry (RFM), an automatic, quick response where individuals mimic others’ expressions, which appears to foster mood sharing during social interactions.
• Dogs and horses were found to display stronger and quicker mimicry responses after perceiving a ROM expression as compared to an attempt to bite, a play pattern that can resemble the ROM expression.

Implications of the Study

• The findings of the study suggest that despite the differences in size, the distance in evolutionary history, and different behavioral repertoire, dogs and horses possess the ability to align their actions, thereby minimizing the chances of misunderstanding and potential aggression.
• Future research could explore the role of ontogenetic pathways (developmental process) and familiarity factors in shaping the inter-species communicative abilities of animals, building the foundation of a universal language for play.