Puppy Dog Eyes: Gaze Driven Chemistry Makes Dogs Out Best Friends
I'll admit it. I'm no dog lover, but even I've felt that pang in my chest when a goofy canine gazes at me with those 'puppy dog eyes.' We have long called these incredibly trusting animals "man's best friend," but new research has revealed that there's more to it than just trust and a mutual love for bacon. Dogs, it seems, can actually hijack the chemistry for human bonding.
That's at least according to a study recently published in the journal Science, which details how a dog's loving gaze actually trigger a powerful oxytocin release in the human brain - potentially a happy consequence of human and canine co-evolution.
Oxytocin is commonly called "the love hormone" and has long been associated with powerful bonding within a species, especially between a mother and her child. Researchers have even seen how this hormone may help facilitate unusual cross-species compassion, where one confused or desperate animal mothers another.
Recent research has even found that the hormone doesn't just help facilitate bonding, but also acceptance of abstract things, such as body image or a taste for foods - something that could prove invaluable to patients battling eating disorders.
That's why it was so shocking to find that gazing back into a dog's eyes can put this hormone into temporary overdrive.
"I love my dogs, and I always feel that they're more of a partner than a pet," Takefumi Kikusui, an animal behaviorist at Azabu University in Sagamihara, Japan, explained to the American Association for the Advancement of Science (AAAS). "So I started wondering, 'Why are they so close to humans? Why are they connected so tightly to us?'" (Scroll to read on...)
To find out, Kikusui and his colleagues reportedly convinced 30 of their friends and neighbors to bring their pets into his lab. They even involved a few people who were raising wolves as pets!
At the start of the study, the researchers collected urine from both pets and humans and then asked each owner to play with their canine while alone in a room. During this time, the researchers observed the standard petting and playful contact, but also a lot of eye contact. The wolves, unsurprisingly, were less prone to make eye contact with their owners - which normally would be interpreted as a challenge in a traditional wild pack. After this play period, urine samples were again taken.
They found that 'puppy-dog eyes' had a stunningly direct impact on oxytocin levels in both canine and humans. The pairs that had gazed at one another the longest saw a 130 percent rise in canine oxytocin and a whopping 300 percent spike in human levels.
The wolf pairs and those who spent little time gazing saw no level spike. Interestingly, the homeone also seems to have an additional effect on female dogs, where an oxytocin nasal spray led to lady-dogs lovingly gazing at their owners 150 percent more than usual. This still led to that 300 percent spike in the owners' levels.
According to the study, this could trigger what's called a "positive feedback loop" where female dogs in particular could quickly develop a strong bond with their owner. (Scroll to read on...)
Kikusui even suggests that this loop helped facilitate the domestication of wild dogs in the first place, and may have enforced what many anthropologists consider a period of co-evolution between man and domestic canines. As oxytocin is also known to help reduce stress in animals and man alike, it could have even been evolutionarily preferable to get this hormone loop working.
"It's an incredible finding that suggests that dogs have hijacked the human bonding system," Brian Hare an expert on canine cognition at Duke University added.
He and Evan MacLean, also of Duke, recently authored a commentary on Kikusi's work, pressing that these results "suggest that dogs have taken advantage of our parental sensitivities - using behaviors such as staring into our eyes - to generate feelings of social reward and caretaking behavior."
Still, Hare adds that "a finding of this magnitude will need to be replicated because it potentially has such far-reaching implications."
And that's an important point. After all, other studies have found that even if canines are unwittingly "hijacking" the human bonding system, how efficiently they do so may vary by a huge number of factors. New mothers, for instance, will always bond more intensely with her child, despite what many dog lovers say about the relationship with their pet.
That's at least according to a study recently published in PLOS One, which showed that despite the bonding hormone oxytocin surging when interacting with a pet, it never triggered the same brain activity that is seen when a mother interacts with the child she birthed. You can read more about that here.
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