JAPAN — Scientists have found the connections between humans and their dogs have the same biochemical basis as the mother-child bond, and it’s strengthened by the same thing: a loving gaze.
A new study in Science led by Takefumi Kikusui, an animal behaviorist at Azabu University in Japan, carried out a series of experiments that examined the impact of the gaze in the dogs and their owners.
They discovered that those puppy dog eyes are even more meaningful than we thought.
“Our data suggest that owner-dog bonding is comparable to human parent-infant bonding,” Kikusui said. “And this is surprising to us because there is not a reproductive relationship between human and dogs, but both of them have acquired similar skills. ”
Oxytocin is a hormone associated with trust and maternal bonding – it increases when you’re close to someone you love and gives you that warm fuzzy feeling.
The researchers found that when owner’s and their canine companions gazed into one another’s eyes during a 30-minute period, levels of oxytocin increased in both the humans and the dogs.
They also found that when oxytocin was administered to dogs, it increased the amount of time that female dogs – but not males – gazed at their owner.
Kikusui said he believed the gaze was acquired by dogs as part of their efforts to communicate and form social bonds with humans.
“Eye gaze from human to animals is usually threatening, not affiliative,” he said. “We speculated that some small population of ancestor of dogs show an affiliative eye gaze toward humans, due to the change in the temperament. In this process, we agree that there is a possibility that dogs cleverly and unknowingly utilize a natural system meant for bonding a parent with his or her child.”
Scientists have a good idea how dogs became domesticated, turning up at some of the first human settlements to take advantage of the left over bones.
But to embed themselves in human society, Kikusui said he believes dogs used their gaze to win over the hearts and minds of those early humans.
Dogs are known to be particularly good at reading their owners moods and that they exhibit a trait known as gaze following – essentially following the actions of humans – much as an infant or child might do.
In a bid to bond with their new neighbors, Duke University’s Evan MacLean said dogs might have come to recognize the importance of the gaze between parents and their children and then saw how that helped them build a similar relationship.
“One fun evolutionary scenario might be dogs find a way to basically hijack these parenting type responses,” MacLean said in a Science podcast. “Over time, dogs may have taken more and more sort of childlike and juvenile characteristics to further and further embed themselves into this parent-child kind of framework.”
But Nicholas H. Dodman, the director of the animal behavior clinical at Tufts University, questioned whether the gaze alone was the reason dogs and humans bonded thousands of years ago.
He said it was more likely the juvenile characteristics exhibited by dogs won over mankind, noting that other interactions between human and dogs such as petting also elevate levels of oxytocin.
“The look is part of the package but it’s not the sole reason why we chose dogs,” he said.
But the bonding isn’t all the dogs’ doing.
MacLean said dog owners play their part, noting that one study found that participants responded very similarly when shown pictures of their dogs as they would their children.
Owners are famous for treating their dogs like members of the family, doting on them, talking to them in child-like voices and even dressing them in special doggy outfits.
“There have been some fun studies showing that, indeed, we respond to our dogs quite a bit like human children,” MacLean said. “One of my favorite ones was a recent brain imaging study that looked at mothers who were being shown pictures either of their own child or somebody else’s child and their own dog or somebody else’s dog. What the researchers found in this study is that there were brain networks in mothers who responded very similarly when they saw pictures of their own child or their own dog but didn’t have that response from looking at someone else’s child or somebody else’s dog.”
Bottom line, MacLean said he felt the Japanese study reinforces the idea that the human-dog relationship is like a parent-child relationship, and could help explain the biological mechanisms that are involved in the use of dogs in therapy to treat everything from autism to post-traumatic stress.
“If it turns out there are benefits of administering oxytocin for some of these disabilities, using assistance dogs may actually be a fairly natural way to stimulate the system,” he said. “There may be some sort of medicinal properties of our interaction with dogs that we could use.”
