Why your dog is overjoyed when you come home

It is one of the most cherished experiences for any dog ​​owner. As soon as you give him the keys to the house, your dog comes to greet you as if you came back from the war and he hasn’t seen you for years.

Reactions can vary from one dog to another: some dogs constantly run around you, others try to reach you by getting on two legs, still others run on the ground… For several minutes, your dog goes crazy with happiness. And it’s not a metaphor. He truly experiences intense joy. But why ?

Neurologist Gregory Berns, a professor at Emory University School of Medicine in Atlanta, was the first scientist to voluntarily give dogs MRI scans. Scientists had already carried out these tests on dogs, but they had to put them to sleep to prevent them from running away from the machines, which emit an unpleasant noise that they cannot stand. However, tests that can be carried out on awake dogs provide much more valuable information.

His experiences served as the basis for the book How Dogs Love Us (Scribe), in which Berns presents the results of his research to the general public. One of his main findings is that dogs perceive humans as a group separate from them, but their owners are considered part of the family. In fact, they prefer to seek help from dogs rather than from other species, which could indicate that dogs are aware that humans have resources that they do not.

By placing the dogs in the scanner and making them smell different odors, Berns found that they could perfectly distinguish between members of their own species and humans, but also between familiar and unfamiliar odors. In particular, the smell of a familiar human being elicits a reward in the brain unmatched by other stimuli.

“No other smell does this, not even the smell of a familiar dog,” explains Berns at io9 magazine. “And it’s not that they see us as part of their wolf pack, they know we’re different. They have a special place for us in their brains.”

A scalable advantage

To understand dog behavior, you need to understand their history. Wolves began to associate with humans around 10,000 to 15,000 years ago, forming a new species whose main characteristic is precisely their relationship with humans.

“The ancestral dogs that associated with humans must have been the most social wolves,” Berns explains in io9. “They hung out with humans and evolved into dogs. What remained of the wolf population were the most antisocial specimens, who wanted nothing to do with us.”

The dog became a much more social animal than the wolf, which contributed to its success as a species.

Despite this, today’s dogs share many characteristics with wolves, including their enormous gregariousness. Wolves live in packs and greet each other by licking each other’s faces, an important social ritual that helps strengthen bonds and obtain information (for example, whether your mate has brought food). It is an important social ritual that serves to strengthen bonds and obtain information (for example, whether your companion brought food).

“It’s important to understand that a wolf pack is a family, literally,” Jessica Hekman, dog expert and author, tells io9. from the DogZombie blog. “It generally consists of the mother, the father, the puppies and a few offspring from previous litters which have not yet become independent. Do dogs consider us part of their family? I think so.”

The dog became a much more social animal than the wolf, which contributed to its success as a species. “You only have to walk around the world to see how many dogs there are,” says Mr. Hekman. “For dogs, [se rapprocher des humains] has proven to be a very effective scalable strategy. There are about 10 million dogs in the world, which means that in many ways the dog has evolved beyond the wolf.”

That’s when we think, “Of course, they love us because we feed them.” But no. “What we found while working with the scanners is that dogs love their humans, and not just for the food,” explains Berns, “they love the company of humans themselves.”

Happiness, a shared feeling

If we don’t yet know most of what’s going on in the human brain, it’s even harder for us to know what animals are thinking, because we have no way of putting ourselves in their shoes. Despite this, most experts agree that dogs feel certain emotions in a very similar way to us. Among other things, happiness.

“In all the exercises we did with the brain scanners – where we presented certain things to the dogs and analyzed their reactions – we observed reactions analogous to those of humans,” explains Berns. “When you see a friend or someone you love, you feel something very similar to what a dog feels.”

For the dog, separation from its master is not voluntary. It is never natural for someone to leave the pack.

This is not to say that dogs have the same communication skills as humans. They are not able to represent things in their memory as we do, they do not have labels or names to give to what they know. Their response is purely emotional, but that doesn’t mean they don’t create a bond with their family. A bond as strong as the one between parents and children.

In 1965, American psychologist Mary Ainsworth designed the “Strange Situation” test, a test aimed at understanding the behavior of children when they are separated from their mothers and have to interact with strangers. When this test was performed with dogs, the results were similar.

As Giorgo Vallortigara, a neuroscientist at the University of Trento, explains in io9, dogs feel affection for their owners and are happy to meet them, in the same way that a child is happy to see its parents. But their reaction to the reunion is much more intense. Unlike our children, we cannot explain to a dog that we are coming back.

“For the dog, separation from its master is not voluntary,” explains Ms. Vallortigara. “It is always abnormal for someone to leave the pack. Wild dogs, like wolves, can separate from the pack for a period of time if sufficiently motivated, but they do so knowing that social contact can be resumed at virtually any time, which is not the case. case when we leave our dog alone for eight hours at home, until we get home from work.

“The exaggerated greetings that can be observed in many dogs are linked to the fact that they have not yet learned to accept the possibility of involuntary separation,” explains the neuroscientist. But there is something else. Dogs are extremely bored when they are alone.

“Your dog has probably spent the whole day with nothing to do and, even worse, he may have been alone, which is unpleasant for a social animal,” says Vallortigara. “Besides being happy to see us, he’s probably feeling a sense of relief because he knows he’ll now be able to do something interesting, like go out and have someone around him.”

It’s a form of greeting, but they also want to lick and sniff you to find out where you’ve been and what you’ve been doing.

The greeting ritual is also essential for dogs, as it is part of their way of obtaining information. “When they jump on you, they try to lick your face,” Berns explains. “It’s partly a greeting, but they also want to lick and sniff you to find out where you’ve been and what you’ve been doing. They are curious. If I’ve been around other dogs, for example, mine know it and start sniffing me more intensely.”

If we want to relieve our dogs of stress, we must respond to their greetings, but there is no need to let them lick our face – although, according to some scientists, it is good for our health. With training, we can teach our pets to greet us differently. What is important is that we understand that for dogs, the greeting ritual is very important. And we cannot ignore it.