For thousands of years, dogs and humans have coevolved in close partnership, developing remarkable social and emotional attunement. Li-Dunn Chen’s 2017 research investigated whether this synchrony extends beyond behavior into physiology—specifically, whether dogs and their owners show correlated hormonal responses to stress.
Previous studies have demonstrated behavioral and emotional alignment between species, including similar stress buffering effects and shared responses to distress. For instance, when owners experience stress or anxiety, dogs often exhibit signs of agitation or concern. Building on this foundation, Chen hypothesized that these shared experiences might manifest as hormonal synchronization—with higher cortisol levels in humans corresponding to higher levels in their dogs.
The study further proposed that the degree of synchronization would depend on the strength and duration of the owner–dog bond. Owners who reported a stronger emotional connection and longer ownership were expected to show greater hormonal alignment with their dogs. This finding would mirror the mother–infant attachment model seen in humans, where close social bonds facilitate physiological co-regulation during stress.
Although the study was exploratory, its framework emphasizes that dogs are sensitive to human emotional states at both behavioral and biological levels. This insight deepens our understanding of the empathic attunement between species and highlights how fostering calm, supportive interactions benefits the wellbeing of both dogs and their owners.
Source: Chen, L.-D. (2017). Variables that Influence Hormonal Synchronization between Humans and Dogs. Published 2017.
