Have you ever wondered how you’re able to welcome your dog into your home? Why can’t we share our beds and kitchens with wolves? Why can’t wolves understand our communicative intentions?
Scientists have tested 3 hypotheses in an attempt to answer how dog social cognition has come to be:
1. Exposure Hypothesis
2. Ancestry Hypothesis
3. Domestication Hypothesis
Exposure (Ontogenetic) Hypothesis
Perhaps a dog’s ability to live comfortably in our homes, follow our gaze, and tolerate our physical adoration of them stems from early exposure. Scientists explored this hypothesis and found that there was actually no difference between litter-reared puppies and those adopted early by humans. Both groups of puppies were safely approachable and could follow our communicative intentions – demonstrating the typical social cognition of dogs. Scientists concluded that a dog’s sociability does not depend on early exposure to humans. This is indicative of “domestication” as opposed to “tameness.”
Ancestry (Phylogenetic) Hypothesis
It was also thought possible that dogs obtained their cognitive ability from their ancestor the wolf. As we discussed, however, wolves do not use our social cues. Interestingly, wolves are approachable and can even live in our homes if reared by humans. However, they are still subject to dangerous, instinctual behaviors. Via exposure, they can be tolerant of or habituated to our presence, but, without training, they still show very little interest in our communicative intentions or in obtaining our attention or affection. Additionally, if that wolf were to reproduce his or her offspring would be just as aggressive towards and fearful of humans as a typical wolf. Their ability to grow accustom to our presence through early exposure is indicative of “tameness” but not “domestication.” Therefore, something changed along the evolutionary path from a wolf to a dog.
Scientists began to wonder if the dog’s sociability evolved during domestication. The idea is that the least aggressive and fearful wolves were the ones able to successfully enter human encampments and scavenge for food. Over time, these docile animals procreated and villagers began housing the nice ones, which eventually gave birth to more nice ones.
In order to test this idea, Dmitry Belyaev began a Silver Fox breeding experiment in Siberia. For more than 45 years, foxes were selected to breed based on their lack of fear and aggression toward humans. After some time, he had a population of domestic foxes – which demonstrated morphological, hormonal, and behavioral changes from wild foxes.
By simply selecting for a lack of aggression, these animals eagerly approached humans, wagged their tails, and barked and cried for attention. They possessed floppy ears, star mutations, curly tails, skeletal gracilization and other physical changes seen in many domestic animals today. The ability to use human gestures also came with domestication. The wild foxes could not understand human gazes and points as well as the foxes selected for least aggression. Interestingly, domestication seems to simultaneously represent the jeuvanilization of a species. Demonstrated by the morphological changes listed as well as their curiosity, desire for attention, and lack of fear, these animals are forever “younger” versions of their wild ancestors. In other words, development up to a certain point is stunted and their behaviors resemble that of a juvenile. Dogs are, in some ways, forever young wolves.
Now that we have a better understanding of how dogs came to be so in tune with our communicative intentions, we can begin to explore why understanding and appreciating the difference between dogs and wolves is so important in working with our companions.