Dogs are man's best friends and scientists say this bond is deeper than we think.
Japanese and American biologists recently concluded that people love their dogs just as much as their children and this feeling is mutual. Researchers confidently state that when a dog and its owner look into each other's eyes, the same hormone is released in both of their brains as in the interaction between a mother and her child. Let's look at the facts in detail.
The biologists at Azabu University in Japan, Takefumi Kikusui and Miho Nagasawa, provide evidence in their latest study suggesting that dogs have used their gaze to win the hearts of humans for thousands of years.
“Miho and I are great lovers of dogs and we feel that something changes in our bodies when we look into the eyes of our dogs,” says Professor Kikusui, who has been a dog owner for over 15 years. This led him to the question: Why do dogs have such a close relationship with humans? The professor sought the answer with his team of biologists and behavioral researchers. The solution lies in the following discussion.
The evolutionary change
The ancestors of dogs, wolves, are wild, strong, and fearsome predators capable of taking down large prey. And yet, tens of thousands of years ago, some wolves attached themselves to humans and developed a close relationship with them. The theory is that the boldest wolves were driven by hunger to the vicinity of human settlements, as they fed on carcasses left at the edges of these settlements. The descendants of these wolves became bolder over generations and ventured closer to humans, following them during their migrations. Over time, humans saw the transformed wolf as a natural ally, discovered its advantages, and began to intentionally breed them for various functions. The question arises: why did this happen? The results may help explain one of the most mysterious stories in human history: how the fearsome, predatory wolf became man's best friend.
“At a certain point in domestication, a small group of friendlier dogs could form a closer bond with humans. Perhaps during the evolutionary process, humans and dogs shared similar social signals such as eye contact and hand gestures. This is why dogs are able to adapt to human society. We believe that some smaller populations of the ancestors of dogs joined humans thanks to a change in temperament. In this process, dogs unwittingly skillfully created a natural and strong bond like that existing between parents and their children,” said Kikusui. Incidentally, dogs do not use eye contact to strengthen bonds with their own species. Researchers suggest that man's best friend claimed a special place in human life long ago through the path of bonding.
The “love hormone” and its effects
They say the eyes are the mirror of the soul. When we look into the eyes of our beloved dog, everything is contained there! Scientists have found that dogs and their owners experience oxytocin waves when they gaze into each other’s eyes. The gaze of love initiates a positive feedback loop, a cycle that releases oxytocin in both humans and dogs, thereby strengthening the mutual bond between them.
Oxytocin, also known as the “love hormone,” is produced in the hypothalamus of the central nervous system and secreted by the pituitary gland. It plays a major role in triggering emotional bonding and maternal behavior during childbirth and breastfeeding, sexuality, and other functions as well. It is a well-known fact that oxytocin is linked to the unconditional love, protection, and nurturing feelings triggered every time parents and their children look into each other’s eyes or embrace.
Professor Kikuosi from Japan proved with experiments that a dog's gaze increases the owner's oxytocin level, along with which the body's endorphin (happiness hormone) and dopamine (reward hormone) levels also rise. In return, the owner's gaze similarly increased these hormone levels in the dog’s body. Thus, a strong positive feedback loop was created in both of their bodies. “This mechanism is the chemical bond between the dog and the human, which unites the thoughts of the two species. The beneficial effect of hugging can also be chemically explained because it positively lifts human mood, and further improves anxiety and depression,” stated Professor Kikusui.
Clive Wynne, a behavioral research professor at the University of Florida, thinks oxytocin may explain why it seems that some owners are more loyal to their dogs than their own families. “A living example is Leona Helmsley, who left her fortune to her dogs rather than her grandchildren,” says Clive.
Proof of the theory
To investigate how the peculiar relationship between humans and dogs develops, Kikusui's team conducted a series of experiments. They observed 30 volunteers and their dogs playing for half an hour, during which they frequently made eye contact and looked lovingly into each other's eyes. The dog breeds included Golden Retriever, Poodle, Jack Russell Terrier, German Shepherd, and some Miniature Schnauzers, with both males and females mixed in terms of gender. Kikusui himself participated in the experiment with his two Poodles. Before and after the experiment, urine tests were conducted, which revealed that oxytocin levels surged in those owners and their dogs who made eye contact most often.
One of the students who participated in the experiment with their dog.
Mutual eye contact had a great impact on both the owners and their dogs. In the pairs (owner-dog) who looked into each other's eyes for the longest time, dogs showed a 150% increase in oxytocin level, while the owners' oxytocin levels rose by 300%. Kikusui found that the owners who looked into their dogs' eyes the longest experienced the greatest oxytocin waves. These owners looked into their dog's eyes multiple times for longer periods, while touching them and talking to them. And the dogs who received the most attention from their owners also showed the highest oxytocin level increases. Nagasawa had already studied the bonding between humans and dogs in 2009, but it has now been definitively proven that both species mutually increase each other's oxytocin levels.
The same cannot be said for wolves. Nagasawa conducted the same experiment with 11 purebred, human-raised wolves. These are not domesticated animals, but they had daily contact with their caretakers who raised, fed them, and occasionally played with them. Despite dogs being descendants of wolves, these wolves did not regularly make eye contact with their caretakers, and their gaze did not trigger an oxytocin increase. “These results suggest that wolves do not use eye contact for social communication with humans,” said Kikusui. The oxytocin bond only works between humans and domesticated dogs, not between humans and wolves.
In the continuation of the experiment, Kikusui sprayed oxytocin under the dogs' noses, then placed them in a room with their owners and 2 strangers. When the dogs received the oxytocin boost, an interesting phenomenon was observed: some dogs, specifically the females, looked longer into their owners' eyes, whose oxytocin levels then increased. Furthermore, due to the external administration of oxytocin, the dogs established more social connections with other dogs and people as well. This second experiment confirmed that one species can chemically trigger bonding with another species.
The same experiment was not performed with wolves, because according to Kikusui: “It is very, very dangerous to apply this with wolves.”
“This positive feedback loop played an important role in dog domestication. As wolves transformed into dogs, only those capable of forming a bond with humans based on protection and care survived. And meanwhile, humans themselves evolved, because they were able to form a strong bond with a new species. This is our greatest theory” – says Kikusui, who suggests that since oxytocin reduces anxiety, adaptation is now important for human survival in today's stressful world. It has a better effect on human health to be less stressed.
Kikusui suggests that primarily this chemical bond helped tame and domesticate wild dogs. Oxytocin is known to help reduce stress in both humans and animals, so during evolution, there could have been no more desirable development than forming such a strong chemical bond with each other.
“We humans use our gaze for affiliative communication and are very sensitive to eye contact. Therefore, those dogs that can effectively use their gaze with their owners are beneficial to humans.” – says Professor Kikusui.
The results suggest that human-dog interactions create the same type of positive feedback bonding in the body as occurs between mothers and their infants. This explains why we feel so close to our dogs and vice versa. According to Kikusui, the nasal spray might have affected only female dogs because oxytocin plays a greater role in female reproductive processes during labor and lactation.
It does not work with wolves
These results are important milestones in understanding how wild wolves may have transformed into domesticated dogs. “In their evolution, dogs probably selected behaviors that trigger this physiological response, thereby promoting bonding,” stated Larry Young from Emory University. “This behavior is looking into the other’s eyes.”
“Eye contact among wolves signifies threat (except between mother and offspring), so they rarely look directly into each other’s eyes. Wolf pups communicated with their mother by looking into her eyes while initiating the same loving cycle that exists in humans. Perhaps when wolves transformed into dogs, they simply retained this childlike communication tool, just as some of their physical traits remained juvenile,” says Larry.
Dogs win our hearts and we, in return, win theirs
In a related article, Evan MacLean and Brian Hare, researchers from Duke University in North Carolina, commented on the result: “These experiments revealed an effective and strong mechanism through which dogs win our hearts, and we in return win theirs.” They add: “These results are significant. They provide information on how dogs became part of human history and show how the relationship with dogs can be beneficial for us.”
“In humans, oxytocin is a connecting link, which mainly increases during interactions between mother and child, that is, during breastfeeding when mother and child look at each other for a long time. In domesticated dogs and wolves, eye contact usually does not indicate bonding; dominant dogs look down at dogs lower in the hierarchy and puppies, who in such cases definitely turn away,” says Evan MacLean, evolutionary anthropologist.
Researchers at Duke University believe that oxytocin creates a neural feedback loop that has strengthened the bond between humans and their best friend, the dog, over millennia. Dr. Evan MacLean explained that dogs have found and mastered the way to form an unbreakable and eternal bond, which has only become important in the last few thousand years. This shows what in our society has led to the dog's eternal friendship with humans.
Our relationship with dogs is very similar to the parent-child relationship. We talk to our dogs as we do to children. Brain imaging studies have shown that there are overlaps in the brain regions that become active when (human) mothers see pictures of their children and their dogs. “Various aspects of our biology seem to coordinate children and dogs in remarkably similar ways,” write MacLean and Hare.
The research was published in America’s largest scientific journal, Science magazine in the spring of 2015.
Please share this post with your friends and other dog lovers as it may be useful to them too! Thank you!
.
More useful and valuable articles for dog lovers can be found on the author’s official website.
Look for Ildikó Vámosi, dog article writer and author’s official website:
Http://ildikovamosi.hu/
🙂 Thank you if you honor me with your visit! 🙂
