Why Are Dogs So Friendly? Science Finally Has an AnswerOur pet canines have alterations in their genes that make them more sociable than wolves, a new study says.By Carrie Arnold
PUBLISHED JULY 19, 2017
https://news.nationalgeographic.com/2017/07/dogs-breeds-pets-wolves-evolution/To Bridgett von Holdt's 11-month-old English sheepdog Marla, the entire world is a friend she has yet to meet.
“She’s hypersocial. I even had her genotyped,” von Holdt admits, somewhat sheepishly (sorry).
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Studies have shown that dogs are more sociable than wolves raised in similar circumstances, generally paying more attention to humans and following our directions and commands more effectively. (See "Can Dogs Feel Our Emotions? Yawn Study Suggests Yes.")
Von Holdt’s background in evolutionary genetics made her wonder about the potential genetic basis for these differences.
Their July 19 study in Science Advances provides an intriguing clue: Hypersocial dogs like Marla carry variants of two genes called GTF2I and GTF2IRD1. Deletion of those genes in people causes Williams syndrome, which is characterized by elfin facial features, cognitive difficulties, and a tendency to love everyone.
Von Holdt suspects that the gene variants in dogs inhibit their normal function, leading to the same issues seen in humans with Williams syndrome.
“We may have bred a behavioral syndrome into a companion animal,” she says.
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In 2010, in collaboration with Monique Udell, an animal behaviorist at Oregon State University, von Holdt searched the dog and wolf genomes and identified alterations in the WBSCR17 gene that occurred during dog domestication, results they published in Nature. (See "Dog and Human Genomes Evolved Together.")
Their project lay dormant until 2014, when von Holdt and Udell secured funding to set up a new set of experiments with 18 dogs of various breeds—including dachshunds, Jack Russell terriers, and Bernese mountain dogs—and 10 wolves habituated to humans.
The scientists trained all of the animals to open a box that contained a piece of sausage. Then they asked the canines to open the box while in three separate situations: with a familiar human present; with an unfamiliar human; and alone, without a person at all.
In all three scenarios, the wolves outperformed the dogs by a large margin. That margin got even larger when the dogs had to open the box in the presence of people.
“It’s not that they couldn’t solve the puzzle, they were just too busy looking at the human to do it,” von Holdt says.(See "Opinion: We Didn’t Domesticate Dogs. They Domesticated Us.")
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We’re now selecting for dogs that are easy keepers, that can spend long periods of time in small apartments," Overall notes. (See dog-evolution pictures.)
“We’re actively changing dog behavior every single year."
