Decades of dog behavior research (Canis familiaris) have suggested that its attachment behaviors to humans would have appeared after its domestication by the latter, nearly 15,000 years ago. This phenotype would have been accentuated during a specific evolution alongside humans. Recent studies, however, seem to contradict this widely accepted theory, and suggest that this behavioral phenotype would have always been present in its ancestor the wolf (Canis lupus). A new study published in the journal Ecology And Evolution supports this hypothesis, revealing that wolves can become strongly attached to their caregivers. This attachment would be even deeper than that of dogs. This discovery could potentially upset our understanding of the evolution of our dogs, whose domestic transition from its ancestor would ultimately be largely misunderstood.
Numerous studies have shown that dogs develop and maintain deep emotional bonds with their masters, a lasting attachment based in particular on affective interdependence. Most of the theories evoked are generally based on the fact that this behavior would have appeared with their domestication by man and that their wolf ancestors would have remained wild. This species (the wolf) is then victim of prejudices and even denigrated through many fables and myths, according to which it would be unable to form any emotional bond and would be only a simple wild animal only guided by its predatory instincts.
However, wolves are by nature sociable animals and show an almost perfect social cohesion within a pack. Behaviors of care and attachment can also be observed in wolves of the same group. One could then logically suggest that by growing up alongside humans, these animals can adopt the same behaviors, the attachment phenotype being already present. In addition, it has been observed in other wild animals that proximity to humans can cause them to become familiar.
” With previous studies making important contributions to this question, I think it is now appropriate to entertain the idea that if there is variation in human-directed attachment behavior in wolves, this behavior could have been a potential target for early selective pressures exerted during dog domestication “, explains Christina Hansen Wheat, researcher in ethology at the University of Stockholm (in Sweden) and lead author of the new study. ” We felt it was necessary to test this extensively “.
These previous studies have notably suggested that, contrary to popular belief, wolves are able to attach themselves to humans, just like dogs. However, the tests carried out at the time would not have been thorough enough to really confirm this hypothesis. The new study by Swedish researchers has established a method revealing for the first time that the attachment of the wolf (raised from birth by humans with conditions identical to domestic dogs) would be even stronger than that of the dog.
Pupils in the same way as dogs
To test their theory, the Swedish researchers raised 10 cubs and 12 puppies from the age of 10 days. For 23 weeks, the animals were raised in exactly the same way, with dedicated caretakers who were familiar to them. They were then subjected to the same behavioral tests, one of which was to bring their handlers and unfamiliar people into their enclosure — causing a stressful situation for the animals. The same experiences in infants indeed demonstrate that a stressful environment can stimulate attachment behaviors, such as closeness and care seeking.
The main objective of these tests is to see if wolves, like dogs, can form special bonds with people who are familiar to them. During the experiments, the 23-week-old Cubs automatically favored their caregivers, towards whom they showed strong attachment behaviors. This result demonstrates that this ability has not specifically evolved in dogs.
Additionally, the researchers found that wolves were more affected by the stressful situation than dogs. ” It was very clear that wolves, like dogs, preferred the familiar person abroad. But perhaps even more interesting was that while the dogs weren’t particularly affected by the test situation, the wolves were. They paced the testing room explains Hanser Wheat.
These results also show that the attachment bonds that wolves develop with their caretakers are perhaps even deeper than those of dogs with their masters. Moreover, the presence of the keepers in the wolves’ enclosure would act as a buffer, because the latter would have immediately ceased to be stressed in their presence. ” Wolves showing human-directed attachment may have had a selective advantage in the early stages of dog domestication “, concludes the expert.
