Human-Dog Bonds Reinforced With Eye Contact, Researchers Say

A new study has found that human and dog relationship is strengthened by holding long affectionate gazes. According to scientists, a special hormone may be responsible for this reinforced bond.

The study headed by Miho Nagasawa from Japan’s Azabu University was published on April 17 in the journal Science and was based on Nagasawa’s previous work in 2009 titled "Hormones and Behavior." In the new study, researchers found high levels of oxytocin in the urine of dogs and their owners after sharing a long gaze.

Researchers in Japan studied how a human-canine relationship can be strengthened. The study basically involved dogs and their owners holding a mutual gaze for half an hour that was recorded on video.

In the first part of the experiment, there were social interactions such as touching, talking, and gazing between dog and its owner. Urine samples were taken before and 30 minutes after these interactions. The results showed that there was an increase in the oxytocin levels in the urine of dogs and owners.

The same experiment was also done in hand-reared wolves and it was found that there was no increase in oxytocin levels for both wolf and owner. This led to the study’s conclusion that gazing is a form of social communication that may have evolved when dogs were domesticated by humans and not something that they have inherited from their wolf ancestors.

In the second part of the experiment, dogs were sprayed with oxytocin through their nasals, and it was found that female dogs tend to stare at their owners longer than male dogs. Both humans and dogs also had a spike in their oxytocin levels.

Oxytocin is a hormone that has several functions in the human body, including reducing stress and triggering onset of labour. In mammals, one of its significant roles is to foster bond between parent and offspring.

According to LiveScience, oxytocin is increased in humans during breastfeeding, when mom and baby gaze at each other, stimulating the release of oxytocin in each other. Nagasawa’s research only suggests that this “oxytocin feedback loop” also happens in other species; in this case, human and canine.

"This tells us something about our relationships with dogs," said Evan MacLean, an evolutionary anthropoligst from Duke University, who was not part of the study. "In many ways, they're similar to our relationships with people."

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