DNA Could Be The Reason Your Dog Is So Friendly

Yep, you’ve got something in common with your dog.

And it’s not just your shared love of long walks and big dinners—it’s your genetics.

In a new study published in Science Advances, scientists sequenced a region of a specific chromosome in dogs and found that multiple sections of canine DNA were associated with differences in social behavior.

The researchers found that a particular part of the chromosome was strongly associated with the “tendency to seek out humans for physical contact, assistance, and information,” according to Science Daily.

In humans, missing genes from a similar section of the genome can cause Williams-Beuren syndrome, often referred to simply as Williams syndrome. Williams syndrome is a rare developmental disorder characterized, in part, by exceptional friendliness; people with the syndrome often interact readily with strangers (we should note that this is only one of the characteristic symptoms of Williams syndrome and that the Williams Syndrome Association is an excellent resource to provide more in-depth information about the condition).

To perform the study, the scientists studied 16 dogs and eight captive wolves.

They analyzed behavioral data by performing an experiment in which the canines attempted to open a puzzle box lid with a human in the room. The scientists measured how long the dogs and wolves took to turn to the human for help with the puzzle.

Unsurprisingly, the domesticated dogs showed more human-directed behavior. After establishing that behavioral basis, the scientists sequenced the animals’ genomes to study the area linked with Williams syndrome in humans.

“It was the remarkable similarity between the behavioral presentation of Williams-Beuren syndrome and the friendliness of domesticated dogs that suggested to us that there may be similarities in the genetic architecture of the two phenotypes,” said Bridgett vonHoldt, assistant professor of ecology and evolutionary biology at Princeton and one of the lead co-authors of the study.

The findings suggest that during domestication, dogs evolved to be friendly.

“If early humans came into contact with a wolf that had a personality of being interested in them, and only lived with and bred those ‘primitive dogs,’ they would have exaggerated the trait of being social,” said vonHoldt.

That trait was likely carried in two genes, according to the new science, and humans appear to have analogs to these genes. To many scientists, that’s what’s most compelling about these results.

“The research provides evidence that there exist certain evolutionary conservative mechanisms that contribute to sociability across species,” said Anna Kukekova, an assistant professor in the Department of Animal Sciences at the University of Illinois at Urbana-Champaign, who played no role in the study. “That they have found that this region contributes to sociability in dogs is exciting.”

Monique Udell, an experimental psychologist at Oregon State University, told The New York Times that dogs’ development was relatively slow when compared to wolves.

“The very things that make life challenging for a human may make dogs successful,” Udell said.