LINKÖPING, Sweden — When humans first began interacting with wolves, some animals were more likely to find a seat by the fire.
The explanation for these “warmer” canines? A new study suggests it has to do with genetic variations affecting the bonding chemical oxytocin. Well known for its role in trust and social relationships in people, the chemical’s role in the selection process that turned wolves into family dogs is now being examined by a group of Swedish researchers.
To test their hypothesis that oxytocin made some dogs more likely to collaborate with people, the researchers devised a simple experiment that would compare what happened when the dogs were given oxytocin to when they received a saltwater placebo. Involving 60 golden retrievers, the study saw the dogs trying to solve an impossible problem.
“The first step was to teach the dogs to open a lid, and in this way get hold of a treat. After this, they were given the same task with the lid firmly fixed in place, and thus impossible to open,” says the paper’s principal author Mia Persson in a press release. “We timed the dogs to see how long they attempted on their own, before turning to their owner and asking for help.”
Sure enough, many of the dogs given oxytocin were quicker to turn to a human for help than the dogs given a salt water placebo. But why didn’t all the dogs given oxytocin respond the same way?
The second part of the experiment provides some answers. The golden retrievers all also had their DNA analyzed for markers of a genetic variant that affects their oxytocin receptors and therefore the strength of their response to the chemical.
Dogs with a specific genetic variation associated with a particular oxytocin receptor response were the ones that were quicker to ask for human assistance.
Finally, the researchers compared the DNA of the dogs in the study to DNA they collected from 21 wolves. The genetic variation correlated with oxytocin receptor response was the same. Accordingly, the scientists suggest that this same variation existed 15,000 years ago when domestication of dogs began.
“The results lead us to surmise that people selected for domestication wolves with a particularly well-developed ability to collaborate, and then bred subsequent generations from these,” says Persson.
The study authors said more research is needed to fully understand the details of the the genetic mechanism affecting oxytocin response and its implications for other species — including people.
“Oxytocin is extremely important in the social interactions between people. And we also have similar variations in genes in this hormone system,” says Per Jensen, who led the research team. “This is why studying dog behavior can help us understand ourselves, and may in the long term contribute to knowledge about various disturbances in social functioning.”
One such further study is currently underway in the Wolf Science Center located in a forest north of Vienna. In that project, involving wolves and dogs treated with oxytocin, researchers will be comparing both pack interactions and interactions between the animals and people.
Another recent study out of the Wolf Science Center has suggested differences in the logical ability between wolves and dogs that may have arisen as a side effect of domestication.
The research paper detailing the Swedish team’s findings on golden retrievers was published in the September volume of the journal Hormones and Behavior.