The tendency of dogs to contact their owners is associated with genetic variations in sensitivity to the hormone oxytocin, according to a new study from Linköping University, Sweden. During their domestication from their wild ancestor the wolf to the pets we have today, dogs have developed a unique ability to interact with humans. One aspect of this is their willingness to “ask for help” when faced with a problem that seems too difficult. However, there are major differences between breeds and between dogs of the same breed. A research group in Linköping has found a possible explanation for why dogs differ in their willingness to cooperate with humans.
The researchers suspect that the hormone oxytocin was involved. Oxytocin is known to play a role in social relationships between individuals, both in humans and animals. The effect of oxytocin depends on the function of the structure that binds it to the receptor, in the cell. Previous studies have suggested, among other things, that differences in dogs' ability to communicate are related to variations in the genetic material close to the gene encoding the oxytocin receptor. The researchers in the current study examined 60 golden retrievers as they tried to solve an unsolvable problem.
“The first step was to teach the dogs to open a lid and get a treat this way. Then they were given the same task with the lid firmly secured and thus impossible to open. The dogs have tried for a long time before they go to their owner and ask for help”, says the main responsible of the article.
Before the behavioral test, the researchers increased the levels of oxytocin in the dogs' blood by injecting the hormone into their noses. As a control, the dogs did the same test after receiving a neutral saltwater in the same way. The researchers also collected DNA using a swab placed in the dogs' cheeks, which determined which variant of the gene for the oxytocin receptor each dog had.
The results showed that dogs with a particular genetic variant of the receptor responded more strongly to the oxytocin spray than other dogs. The propensity to approach their owner for help increased when they were given oxytocin in their nose, compared to when they were given the neutral saltwater solution. The researchers suggest that these results help us understand how dogs have changed during the housing process. They also analyzed DNA from 21 wolves, and found the same genetic variation among them. This suggests that the genetic variation was already present when the domestication of the dogs began 15,000 years ago.
