Welcome to the iCover blog pages ! Experiments by Japanese neuroscientists carried out in 2015 led to an amazing conclusion: the formation of empathy between the owner and his dog becomes possible thanks to a subtle mechanism of positive feedback, similar to that which takes place in the relationship between mother and child. It turned out that, unlike tamed wolves, dogs often seek to catch the eye of the owner, which entails a pronounced increase in the latter level of the neurohormone oxytocin, which is responsible for the development of feelings of affection, care and the formation of a positive emotional background. We will tell you more about the results of the research carried out in our today’s article.
Most of us would agree that the dog is man’s friend, but until recently we had no idea how complex the communication mechanisms that have been formed in a pair of “man-dog” over the millennia.
In terms of their ability to effectively communicate with humans, dogs not only significantly surpass their closest wild relatives – wolves, but also managed to outstrip our conditional relative – chimpanzees. One of the parameters of such communication is the ability of the domestic dog to understand the meaning of the human gaze. Many human communication skills, including the understanding of intonation and gaze, according to scientists, dogs managed to master in the course of evolution. The researchers explain this by the fact that individuals who better understand the mood and wishes of their owners had some selective advantages in the process of domestication.
The exchange of information with the help of a glance is one of the most ancient ways of communication inherent in humans and is responsible for the formation of an emotional connection between “friends”, in particular, between a mother and a child. Today it has been proven that when the baby looks at the mother, the level of the hormone oxytocin in her brain and in the blood rises, thereby stimulating the manifestations of maternal affection and care. The consequence of the latter is an increase in the level of oxytocin in the hypothalamus of the child, which stimulates the latter to further consolidate the experience gained. This is how a positive feedback mechanism is formed in people.
Experiments and their results
Studies have shown that human attachment to their four-legged pets takes place both emotionally and at the neurological level. Scientists are convinced that positive feedback, maintained through the exchange of glances in the eyes and at the level of oxytocinergic neural networks, is one of the essential factors in the formation and development of full-fledged relationships, expressed in love and understanding between mother and child. But can such perfect mechanisms for stimulating such feedback, which are formed as intraspecific ones, develop in the relationship between the owner and his dog? And can oxytocin act as a catalyst for this process for both?
A group of Japanese neuroscientists began looking for an answer to the second question. The results of the latest experiments were published in the journal Science . Earlier, the same team of scientists experimentally proved that the dog’s gaze is indeed capable of increasing the level of the neurohormone oxytocin in the host’s body. During the experiment, the level of oxytocin in the urine of the owner was measured before and after half an hour of communication with the dog. As it turned out, the longer was the duration of the “session” during which the dog looked into the eyes of its owners, the higher the level of oxytocin was recorded in the owner at the end of the experiment. A number of recent studies from 2015 have answered the question of whether oxytocin levels increase in dogs. The experiment was attended by wolves raised from the first years at home. A total of 30 dogs of different breeds and 11 domesticated wolves with their owners took part in the study. As in the first case, the level of oxytocin (this time in four-legged friends) was measured before and after the experiment. The half-hour stay of the owners and their pets was filmed. It was forbidden to feed and give toys to animals, there were no other restrictions. As with the results of previous studies, in the latest experiments of the pair “man-dog” clearly identified two groups: with weak and strong friendships. The last group included dogs that often look into the eyes of the owner and owners, focusing on their attachment to their wards in the questionnaires. In the first group, the owners, on the contrary, showed restraint of emotions, and the dogs did not show any particular desire to catch the owner’s eye.
Left – the time during which the dog looked into the eyes of the owner in the first five minutes of communication. Black column – dogs, which have the warmest relations with the owner (LG group), white – SG group; the gray column (the height of which is zero and therefore it is not visible) – tame wolves that do not look their owner in the eye at all. Top right – the level of oxytocin in the host’s body before and after the experiment, bottom right – the same in the body of a dog (or wolf). The report says LG’s dogs have been the longest eye contact. The overwhelming majority of wolves did not do this, which is understandable, since for them looking in the eyes is associated with a threat. In the LG group, by the end of the experiment, the level of oxytocin increased significantly in humans, slightly less in their pets. In the SG group and in wolves and their owners, the level of oxytocin remained practically unchanged. Moreover, the LG group (as opposed to the other two groups) showed a positive correlation between dog gaze duration and elevated oxytocin levels in humans and dogs. Another important detail was noted: for other parameters of behavior that were recorded during the experiment (conversations between the owner and the pet, the duration of games and stroking), their relationship with the level of oxytocin was not so obvious, although those owners whose dogs looked at them for longer, stroked more often their pets.
Thus, the scientists came to an unambiguous conclusion: the dog, looking into the eyes of the owner, manipulates the level of oxytocin in his body (primarily in the blood and brain).
No less interesting were the results of the second experiment, during which 27 pairs of subjects took part, divided into two groups. Dogs of one group received oxytocin dripping into the nose, dogs of the other group – saline. After that, the dog was launched into the room, where the owner and two more unknown people were nearby. In this case, to people in the room, any external manifestations of attention (stroking, maintaining a conversation, foreign objects) that could affect the purity of the experiment were excluded. In the course of the experiment, it turned out that the dogs that were injected with oxytocin looked at their owners longer than the representatives of the second group. At the same time, such a dependence was clearly observed only in bitches, while the behavior of males was not influenced by pernasal administration of oxytocin. According to the authors, one of the possible explanations is that the administration of oxytocin in males stimulates not only oxytocin, but and the vasopressin system, which controls aggressive and territorial behavior, which heightens alertness towards outsiders. Interestingly, the gender-specific tendency for oxytocin to influence behavior is also largely observed in humans.
The most interesting and significant result, according to the authors of the second experiment, was the increase in the level of oxytocin in the owners of bitches, which, according to the conditions of the experiment, could not help but touch or talk with their four-legged girlfriends, communicating with them only at the gaze level, recorded after the end of a half-hour communication session … In pairs belonging to the group, dogs in which were not subjected to instillation of oxytocin, in the presence of strangers, changes in the level of oxytocin were not recorded in either the dogs or their owners. The results of the experiments can be considered as a convincing argument in favor of the hypothesis of Japanese scientists: in the development and maintenance of mutual affection between a dog and a person , a positive feedback loop with the participation of the neurohormone oxytocin is actually involved, similar to that which determines the formation of mutual attachment between mother and child. Evidence that no such connection arises between wolves and their owners indicates that the latter developed in dogs in the process of domestication, and was not inherited by them from their wild ancestors. Perhaps the development of this tendency increased the chances of the distant ancestors of today’s dogs to adapt to life among humans.