Science

Dogs cry (literally) for joy when reunited with their owner, study shows for the first time

⇧ [VIDÉO] You may also like this affiliate content (after ads)

Since domestication by humans, the dog (Canis familiaris) has evolved to adopt behaviors adapted to humans and compatible with the needs of both. Unexpected social-cognitive skills have been repeatedly demonstrated scientifically in dogs, in particular through certain factors such as eye contact or noises. A recent study published in the journal Current Biology shows for the first time that a dog has such a strong bond with its owner that it cries (literally) in excitement when it finds it after a long separation.

Visual contact will play a fundamental role in the development of affection between a dog and its owner. For example, a dog has developed over time the muscles that raise its eyebrows to evoke tenderness in its owner or induce protective and caring behavior in it.

Over thousands of years of evolution, a special bond has been established between humans and dogs, but few scientific studies have been devoted to this area. However, certain dog abilities suggest that they can establish a high level of complicity with their owner. The closest examples are German Shepherds in the service of some armies, which develop extraordinary abilities due to a high degree of trust in their owners or trainers. More rationally, it would be a win-win system, when the owner benefits from the services of the dog, and in return the latter is rewarded and fed.

But in addition to the basic needs between the owner and his dog, there would be deep emotional ties and needs. Previous research has also shown that dogs’ sociocognitive abilities that are attractive to humans will be very similar to those of children and infants, such as when they express pain or hunger. Just like in babies, this behavior evokes gentle behavior in the dog’s owner.

The charmingly whiny and cute look that many dogs retain even into adulthood should evoke caring behavior not only in the mother (who also sheds tears during whelping or lactation), but also in the owners. Thus, visual contact between dog and owner initiates interaction and stimulates the secretion of oxytocin in humans, a hormone involved in, among other things, creating bonds between people.

In humans, depending on the degree of positive or negative emotions, this hormonal pathway activates the lacrimal glands and triggers the production of tears. Therefore, researchers from Azabu University (Japan) wanted to know if the same biochemical phenomena are caused in a dog during its affectionate interaction with the owner.

When dogs find their owner, they express their joy by whining, jumping, tail wagging, etc. A Japanese study found that their physiological levels of oxytocin increased significantly at this time. “This gave me the idea that oxytocin can increase tearing. So we did an experiment to reunite owners,” says Takefumi Kikusui, professor of veterinary medicine at Azabu University and co-author of the new study. Notably, this is the first demonstration of tear secretion as a result of positive emotions in a non-human mammal.

Dogs will have more attachment to their “real” owners.

It all started when Kikusui noticed that her poodle’s eyes watered when she was feeding her puppies. The researcher then calculated that these “tears” could be explained by the high levels of oxytocin the dog had at the time.

To test their theory, the researcher and his team enlisted dogs and their owners for a few simple experiments. First, we measured the amount of tears the dogs had when they were reunited with their owners after being away. To see if dogs are actually kind to their owners, a second experiment measured the tears the dogs shed when they found people close to their owner. Approximately twenty dogs were involved in each experiment, in which the strips were used to measure eye dryness and tear secretion (in addition to tears caused by irritation caused by the strip).

Results: The volume of tears increased significantly when the dogs were reunited with their owners, compared to being reunited with familiar owners. The researchers also noticed that this volume increased even more when the dogs were given drops of oxytocin.

Another experiment was also done to see what could cause owners to have tears in a dog. To do this, the researchers asked participants to look at photos of dogs that had or had not previously been artificially induced tears and asked how much they wanted to take care of them. All the participants then said that they wanted to take care of the dogs with tears in their eyes.

Current Biology.

Back to top button

Adblock Detected

Please consider supporting us by disabling your ad blocker.