Man’s best friend is more than just a saying – it is based on scientific truth. At least that’s what a study published earlier this month found out when it compared how dog pups and human-raised wolf pups interact with humans.
The study, published in Current Biology, found that dog pups are more attracted to humans, read human gestures like pointing more skillfully, and have more eye contact with humans than their close relatives, wolves, even when the wolf pups were raised by almost human birth.
It is the largest study to date to investigate the domestication hypothesis, which posits that dogs’ ability to understand human communication is a product of generations of domestication, rather than the training a dog undergoes in a single lifetime.
“We already know that dogs have really strong social skills when it comes to working specifically with people,” said Hannah Salomons, lead study author and PhD student in Duke University’s Department of Evolutionary Anthropology. “But the question was still open whether this was something they inherited from their common ancestors with wolves or something that evolved during the domestication process.”
To find the answers, Salomons and her team spent six years testing over 80 furry friends with a series of cognitive tests designed to measure temperament, memory, and social skills. All of the puppies were between five and 18 weeks old, with most falling within the eight week range.
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Solomons partnered with two organizations to get their fluffy themes. The first was Canine Companions for Independence, a national organization that breeds assistance dogs. These doggos, all retrievers, had minimal human interaction during their first eight weeks of hopping around. Instead, they spent most of their time with their siblings and birth mother.
The class photo of the Duke Canine Cognition Center’s spring 2020 puppy kindergarten. The seven puppies from Canine Companions for Independence are part of a long-term study funded by the National Institutes of Health to investigate the effects of various rearing strategies on the behavior and cognitive development of assistance dogs. Jared Lazarus
The second organization was the Minnesota-based Wildlife Science Center, which raises orphaned wolves and occasionally breeds them for educational programs. In contrast to their domesticated conspecifics, the wolf pups spent 12 to 24 hours a day in human care from around 10 days after birth up to and during the entire test period. Caretakers hand-fed the baby wolves and even slept with them outside on mattresses.
“We wanted to raise the wolves with more human interaction than the dogs,” said Solomons. “So if [social skills] had learned, the wolves would have every opportunity to learn. ”
Even so, the study found that domesticated puppies were 30 times more likely to approach a stranger and five times more likely to approach a familiar person. In addition, this measurement is most likely an underestimate as many wolves were excluded from the study because of their uncooperation.
“Many of the wolf pups were so shy of humans that we couldn’t even test them,” said Solomons. “They just cried or barked at the gate and tried to escape.”
In another test, the experimenters hid food in one of two bowls and then pointed to the bowl of goodies. After their release, dog pups were twice more likely than wolf pups to choose the bowl pointed to by the experimenter.
When the experimenters placed an unfamiliar object, such as a plastic teddy bear, next to the hidden nibbles instead of gesturing, dogs were still 2.5 times more likely to approach the correct bowl. They were also more likely to have eye contact with the experimenter. However, if the object was familiar, that is, it came from their playpen, dogs and wolves would approach it approximately equally often.
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In addition, dogs and wolves cut on memory tests such as
The study concluded that these results taken together support the idea that the people who became more sedentary chose wolves who were friendlier and more cooperative from generation to generation. Over time, domestication changed the social perception of dogs so that they could communicate better with people.
“From an evolutionary point of view, this is really exciting because we are figuring out how domestication affects the social development of an animal’s mind,” said Solomons. “We also hope that the results of our research can help us see if any of these tests predict which puppies will grow to be the most successful service dogs.”
More research is needed to determine how dogs develop these innate abilities over the course of their lives. Salomons also hopes that future research could reveal clues on how we can train dogs to communicate with us more efficiently.