Few animals show as much affection and loyalty as dogs. But a new study provides evidence that the same human-animal bond can develop in wolves, too.
While previous studies have suggested something similar, there isn’t much previous research on bonding between wolves and humans, and the results have varied. Here, the study team wanted to take a standardized approach, with a test group of dogs and wolves raised under identical conditions from birth.
Between 40,000 and 15,000 years ago, dogs were domesticated by now-extinct wolf species, and the researchers believe their findings could shed new light on what traits evolved through domestication, and what traits were present in the first place.
“Wolves that show human-centric attachment may have had a selective advantage in early stages of dog domestication,” says ethologist and lead author of the study, Christina Hansen Wheat of Stockholm University in Sweden.
The study examined the responses and behaviors of 12 Alaskan husky dogs and 10 European gray wolves (wolf) in the so-called strange situation test, a standard scientific test originally used in children to assess attachment to their caregivers and adapted for dogs (and in this case wolves) 20 years ago.
The dogs and wolves were raised by trained caregivers from 10 days to 23 weeks of age and subjected to an approximately 15-minute experiment.
In it, the primary female caretaker of the wolves and dogs alternated with a strange woman circling in and out of a room engaging with the animals, whether through active play or, when the animal was occupying her, petting.
Like the dogs, the wolves showed more affection and spent more time greeting the familiar person and made more physical contact. The familiar person was also more likely to be followed to the door when exiting.
“It was very clear that the wolves, like the dogs, preferred the familiar to the stranger,” says Hansen Wheat.
“But perhaps more interestingly, the dogs weren’t particularly affected by the testing situation, but the wolves were.”
Compared to the dogs, wolves exhibited more stress- and anxiety-related behaviors when interacting with strangers, including pacing, squatting, and tail-ticking.
These behaviors coincided when the stranger entered the room and when the stranger and the wolf were in the room without the familiar person.
When the familiar human returned to the room, these behaviors would be less pronounced. In other words, it seemed as if the familiar person acted as a kind of “social buffer” for the wolf.
Scientists continue to study how dogs and wolves are alike and dissimilar to understand their evolutionary history – but it seems there are some key similarities when it comes to bonding with humans. However, the differences suggest areas that should be further explored in future research.
“Together with previous studies that have made important contributions to this question, I think it is now appropriate to consider the idea that if there are differences in human-directed attachment behavior in wolves, that behavior is a potential target for early could have been selective pressures exerted during dog domestication,” says Hansen Wheat.
The research was published in ecology and evolution.