By Dr. Becker
It’s thought that modern dogs have one common ancestor — the Eurasian grey wolf. At some point in the past, roughly 30,000 or 40,000 years ago (the exact timeframe is a subject of great debate), a subspecies of wolf likely began interacting with humans, perhaps as the animals searched for food at human settlements.
Interactions between wolves and people ultimately led to domesticated dogs who are able to recognize and respond to human communication cues and developed into the pets we know and love today.
Modern dogs share more than 99 percent of their DNA with wolves, but there are key differences between these species. This may seem obvious since dogs are domesticated and wolves are not, but would the differences still hold true if the wolves were domesticated in a sense too? Research published in the journal Royal Society Open Science addressed this very topic by studying wolf puppies hand-raised by humans.1 Would the pups grow into adult wolves that behaved just like domestic dogs?
Wolves Raised by Humans Become Attached to Their Caregivers
Previous research has suggested that wolves show signs of attachment to their human caregivers when they’re very young (3, 5 and 7 weeks old) but lose that attachment by 16 weeks, unlike dogs, which bond with their owners well into adulthood.2 The featured study, however, found otherwise, showing that even adult wolves show a certain level of affinity for the humans that raised them.
The study involved wolf puppies raised by humans (as part of the Family Dog Project) in the same way dog puppies would be raised. The wolves were walked on a leash, cuddled, groomed and so on, just like dogs. The wolves then engaged in greeting tests at varying ages, in both group settings and as individuals, with their caregivers, close acquaintances, people they’d met just once and strangers they’d never met before.
At 6 months old, and then again at 12 months and 24 months, the wolves’ reactions were closely tracked during the greeting sessions. The wolves readily greeted all the visitors, but greeted their close caregivers in an “intense and friendly” way, particularly when they were 6 months old.
As they got older, they still showed affection toward their caregivers and close acquaintances, but were more reserved, and a tad fearful, toward the less-familiar visitors. In case you were wondering, a wolf “greeting” is much like one you might receive from your dog. The researchers wrote:3
“Wolf greeting is characterized by active submission, friendliness and tolerance. In the course of this ceremony the younger pack member (offspring or younger sibling) excitedly nips at, licks and smells the mouth of the adult (usually parent or older sibling) individual. This behavior is usually coupled with a low tail wagging, a lowered body posture and with lowered ears, held close to the head.
Wolves socialized to humans will greet them in a very similar way, thus active greeting towards humans involves face-oriented licking, jumping, pawing, contractual leaning and rubbing.”
Wolves Are Not Dependent on Their Caretakers Like Dogs Are
While there were many noted similarities in the wolf-human relationships as compared to those between a dog and his owner, there were definite differences as well. With their cuddly dog-like appearance, it’s tempting to assume that wolves raised by humans would turn into veritable dogs.
But as Gizmodo put it, “it’s important to remember that wolves — even those raised by humans — are not dogs. Not by a long shot”4 — and the Royal Society Open Science study demonstrated this precisely. The study’s lead author, Dorottya Ujfalussy, Ph.D., from Eötvös Loránd University in Hungary, told Gizmodo:5
“What we learned from our study is that while dogs may be more attached to their human caretaker in the sense of dependence and using their owners as a secure base, wolves are also able to form lasting affiliative relationships with their caretakers, though without a sense of dependence …
This paper supports those earlier findings that wolf pups do seem to form attachments and that while they are not dependent upon their caretakers later in life a social bond does seem to persist into adulthood.”
This makes sense since, by about the age of 4 months, wolves are no longer dependent on their mothers and spend a lot of time on their own. This independence and lack of dependence on their caregivers as the wolves progressed into adulthood may have been regarded in some earlier studies as a lack of attachment. The study also revealed that hand-raising wolves also seemed to promote a general affinity for humans among the wolves, which could have implications in settings where wolves are kept in captivity.
“Our results call for some caution,” the researchers wrote, “how unfamiliar people should interact with intensively socialized wolves that seem to have a strong interest to approach such people while having also conflicting motivations driven by fear.”6
Wolves Solve Puzzles With Persistence, Dogs Look to Owners for Help
There’s no doubt that, despite their close genetic ties, major differences exist between wolves and dogs. In 2015, research once again highlighted the fact that wolves behave independently while dogs very much depend on their owners, even when trying to solve a puzzle. The study involved 10 pet dogs, 10 shelter dogs and 10 wolves given three opportunities to open a puzzle box (a covered plastic container containing a bit of sausage, with a rope that would open the box when pulled).7
The animals were given access to the puzzle boxes under different scenarios. In one test, the animals were left alone with the box for two minutes. Eight of the wolves opened the box during this test, compared to one shelter dog and no pet dogs. In the next test, the animals were given access to the puzzle with an experimenter standing nearby. The results were nearly identical: eight wolves succeeded in opening the box as did one pet dog, but no shelter dogs solved the puzzle.
Of note, the dogs spent much more time gazing at the human than the wolves did. The dogs that had previously failed to open the puzzle box were then given another chance, during which a human used gestures and spoke positively to encourage the dogs to keep trying.
This time, four of the shelter dogs and one pet dog solved the puzzle, and all the dogs spent much more time trying to solve the puzzle than they had previously. While the wolves were persistent and independent, working hard to solve the problem on their own with little notice or expectation of help from humans, dogs preferred to get help from their owner.
Eye Contact Is Another Giveaway That Wolves and Dogs Are Very Different
Domestic dogs are more likely to make direct eye contact with humans than wolves raised in the same environment.8 This simple difference may be responsible for a key part of the differences between dogs and socialized wolves, according to research in Current Biology.
“Since looking behavior has an important function in initializing and maintaining communicative interaction in human communication systems, we suppose that by positive feedback processes (both evolutionary and ontogenetically) the readiness of dogs to look at the human face has led to complex forms of dog-human communication that cannot be achieved in wolves even after extended socialization,” the researchers wrote.9
While wolves have adapted their own form of gaze signals to help them hunt in packs, dogs look at human faces to read emotional signals and more.
Mutual gazes between a dog and its owner even lead to increases in levels of oxytocin, the “love hormone.” Interestingly, the same rise in oxytocin is not seen among wolves raised by humans, even though gazes were shared among the animals and familiar owners.10 This increased feeling of trust and bonding between dogs and humans may be one reason why dogs, and not wolves, have developed into man’s best friend.