Pet dogs exhibit social preference for people who synchronize with them: what does it tell us about the evolution of behavioral synchronization?

Humans show greater affiliation with people who are behaviorally synchronized with them but little is known about the impact of synchronization at an interspecific level. We, therefore, explored whether the synchronization of humans with dogs affects dogs' human preferences. Pet dogs were exposed to two unfamiliar persons: one synchronized her walking behavior with them and one walked randomly. In a preference test, molossoids exhibited a clear social preference for the synchronized person, unlike shepherds. We conclude that pet dogs show a greater affiliation with humans who mimic their walking behavior, although genetic selection modulates this propensity. Behavioral synchronization, therefore, acts as a social glue in dogs too. It is the first time that such a human-like ability has been highlighted in domesticated canids at an interspecific level. Implications for the evolution of behavioral synchronization are discussed.