Wolves might have a savage reputation, but it looks like they can develop a deep bond with humans and even miss the company of specific people if they’re raised by humans and intensively socialized, much like their dog cousins. 

Dogs have been humanity's’ best friend for thousands of years, with most estimates saying dog domestication occurred somewhere between 10,000 and 40,000 years ago. A cornerstone of this long and fruitful relationship is the ability of dogs to show an attachment towards their human owners. However, the evolutionary origin of this trait has remained unclear. How did this ferocious wild predator become so soppy? Well, it appears that wolves are also prone to this affectionate behavior and it might stem from their keen ability to form social bonds with pack members.

In an attempt to sniff out the origin of the dog-human attachment, researchers at Eötvös Loránd University in Hungary studied captive hand-raised grey wolves – the closest living relative of the domestic dog – and the relationship with their human handlers. 

As reported in the journal Scientific Reports, the researchers gathered 11 captive wolves, all of whom were individually hand-reared by humans as pups, and put them through a separation test, in which they were left alone by their handler or by a stranger for three minutes in an unfamiliar place. They compared their reactions to nine dogs in the same scenario, all of whom were the pet of a human family.

“We were surprised how little difference was between the wolves' and dogs' behavior during the test. When their handler – or owner in case of the dogs – was present they were calmer, they spent their time exploring their vicinity and sniffing around,” Tamás Faragó, lead author of the study from the Department of Ethology at Eötvös Loránd University, said in a statement.

“But when they were left by their handler, they became stressed, whined and pulled the leash towards her hiding place. However, when the stranger disappeared these behaviors barely appeared.”

There were some differences between the dogs and wolves, however. The pet dogs appeared to be more interested in humans, regardless of whether they were familiar with the individual or not, which they believe is a sign of the genetic differences between dogs and wolves. 

The researchers also hastened to stress that the wolves in this study were captive and very familiar with humans, meaning they’re not strictly the same as the wild wolves you’ll find prowling around the forests stalking deer. With that limitation in mind, they maintain their research could shed light on how attachment towards humans in dogs might have originated.

They explain that young wolf pups do not form such relationships with their mother. However, they do appear to pick up these bonds at a later stage in life. As opposed to a mother-pup dynamic, the researchers argue the bond “might have originated from the social bond between the members of the wolf pack, that has a very similar social structure to human families, in which companion dogs live today.”