Our relationship to animals has a profound effect on the biochemistry of our brains; here’s how: An oxytocin boost There are documented physiological changes in people who spend as little as 15 minutes with a dog or cat or participate in equine therapy—Their oxytocin levels increase. Dubbed the “love” or “hug” hormone, oxytocin creates a profound sense of peace and comfort. It also slows the heart rate, breathing, and blood pressure in addition to reducing stress hormones. Normalizing brain chemistry A study by University of Missouri scientists documented that petting a dog can cause a spike in one’s serotonin level, the neurotransmitter that most antidepressants attempt to increase. Pets can profoundly change the biochemistry of our brains, so it’s no wonder that pet-assisted therapies help people with autism and those suffering from PTSD and drug addiction. To read more on this story, click here:How Animals Help Brain Chemistry
While this might seem ridiculous to some, a study in Science proves the bond between dogs and their owners can be as emotionally strong as the connection between mothers and their children. It's the latest in a growing body of science that explains how dogs have gained such an important place in human society. "Owner-dog bonding is comparable to parent-infant bonding," writes Takefumi Kikusui, from Azabu University in Japan, via email. "And this is surprising to us … because there is not a reproductive relationship between humans and dogs." But any dog lover who has gazed into the big eyes of a pleading pup is not surprised. Previously, the researchers had shown the eye connection between dogs and humans increases the levels of oxytocin in people. Oxytocin, aka the "cuddle chemical," is a hormone mammals produce in the brain that encourages bonding between mothers and their offspring. It's also involved in partner and social bonding. Most evidence shows this kind of connection works within a species — humans produce oxytocin because of other humans, and dogs produce it because of other dogs. But this study is the first to show the hormonal bonding between dog and human. That is, the feeling is mutual. In the first experiment, the researchers measured oxytocin levels in 28 pairs of dogs and their humans before watching them interact for 30 minutes. People talked, petted and looked at their canines. Afterward, the researchers screened oxytocin levels again. The owners and pups that gazed at one another more showed increased oxytocin. Humans "use eye gaze for affiliative communications and [are] very much sensitive to eye contact," said Kikusui. "Gaze, in particular, (over touch, for example) led to the release of oxytocin." For the second experiment, the researchers dosed 54 dogs with either a spray of saline or oxytocin in the nose. The female dogs treated with oxytocin spent more time gazing at their owners, which after 30 minutes boosted the levels of their owners' oxytocin. "[This] suggests that this gaze behavior is really critical in oxytocin release," said Evan MacLean, senior research scientist and co-director of the Duke Canine Cognition Center, who wrote an article about the findings. "When they receive oxytocin, this causes dogs to look more at people and the more they look, it boosts [oxytocin levels] more." What's more: Wolves, which dogs descended from about 30,000 years ago, do not experience an increase in oxytocin from gaze. "This means that dogs have acquired this superior ability during [the] evolutional/domestic process living with humans," says Kikusui. This provides more evidence of how deeply dogs are attuned to humans. "We make the claim that dogs might have hijacked [the oxytocin] pathway. It is in place in humans and we use this in our romantic relations and with children. And we know it is important," says MacLean. "This is sort of an accidental thing that happens over … time." "This special bonding relationship with dogs is fairly unique," he says.
When people call their dogs their "fur babies," they may be onto something, at least on a chemical level. Dogs that make so-called puppy eyes at their owners get a spike in the "love hormone" oxytocin — and their owners do too, according to a new study. This same positive feedback in oxytocin release occurs when a mom gazes at her newborn infant, studies have shown. Because dogs don't otherwise use eye contact as a way to cement bonds with other dogs, the study researchers suggest that man's best friend may have gotten its prized place in human hearts by tapping into an ancient human bonding pathway. "We humans use eye gaze for affiliative communications, and are very much sensitive to eye contact," study co-author Takefumi Kikusui, a professor of veterinary medicine at the Companion Animal Research Lab at Azabu University in Japan, said in an email. "Therefore, the dogs who can use eye gaze to the owner efficiently would have more benefits from humans." Loving Feeling Oxytocin, often called the "love hormone," performs various actions in humans, such as triggering the onset of labor, reducing stress and helping group members recognize individual members. But in all mammals, one of its key roles is to help a parent and infant bond. For instance, when rodent pups are separated from their moms, they emit a series of ultrasonic noises that spur moms to release more oxytocin and to scoop up their pups and behave in a more nurturing way. This, in turn, leads to the release of more oxytocin and, as a result, more attachment behavior in pups. In humans, both moms and babies get a spike in oxytocin during breast-feeding, and they will spend hours gazing at each other, each fueling the release of oxytocin in the other, various studies have suggested. For domesticated dogs and wolves, however, eye contact isn't normally a bonding behavior. Rather, dominant dogs stare down canines lower in the group's hierarchy, and pups that are nervous will look away, said Evan MacLean, an evolutionary anthropologist at Duke University who was not involved in the new study. Gazing Behavior Kikusui and his colleagues wondered exactly what dogs are getting out of their affectionate gazing at humans. In the new study, which is detailed in the journal Science, the team measured the oxytocin levels of dogs and their owners before and after the pairs spent 30 minutes together. After the owners spent quality time gazing into their dogs' eyes, petting and talking to the furballs, both the people and dogs showed increases in the levels of oxytocin in their urine. What's more, the more oxytocin rose in humans, the more it did in dogs as well. In similar experiments with wolves, the researchers found no such interspecies-oxytocin loop — even though the wolves were interacting with people who had raised them from pups. In a second experiment, the researchers spritzed an oxytocin nasal spray into dogs' nostrils and found that female dogs stared longer at their owners afterward, and that both the pups and the humans showed a rise in oxytocin as a result. The findings suggest that the oxytocin feedback loop can cross species boundaries, at least between man and his best friend. "This tells us something about our relationships with dogs," MacLean, who wrote a Perspectives article in the same issue of Science, told Live Science. "In many ways, they're similar to our relationships with people." Partners in Evolutionary Change The findings may help explain one of the most puzzling stories in human history: how a predatory, fearsome wolf transformed into man's best friend. Kikusui speculated that, at some point early in the domestication of dogs, a small group of naturally more friendly dogs may have gazed at their human counterparts for bonding. In doing so, the dogs unwittingly tapped into the natural human system designed for parent-child bonding. Humans and dogs may have co-evolved this ability in order for love to flourish across species, Kikusui speculated. In follow-up research, they hope to identify the genes involved, in both humans and dogs. MacLean, however, doesn't think humans necessarily needed to undergo genetic changes to get an oxytocin boost when they lock eyes with their canine companions. "Originally, this kind of bonding mechanism was very important between mother and infant, and then we've probably already recycled those same mechanisms in our relationships with other individuals," MacLean said. Therefore, the human ability to bond via eye contact is already very flexible and easily repurposed, he added.
