Dogs have long been considered man’s best friend. They love to join us on adventures, cuddle on the couch, and faithfully protect our homes from intruders. Because of this, more than 69 million households in the United States are home to at least one dog.
But why is that? What makes dogs so much friendlier towards humans than wolves and other species?
Dogs are friendly towards humans because of their genetic makeup. Domesticated dogs have several genes that differ from wolves; these genes produce hypersocial traits in dogs. Interestingly enough, the genes that cause dogs to be so friendly are also found in people diagnosed with Williams-Buren syndrome, which causes hypersocial behavior.
In the rest of this article, we’ll talk more about the scientific reason that dogs are so friendly.
Why Are Dogs So Friendly?
Over thousands of years, dogs have evolved from wild wolves to the loving house companions we all know and love today. Possibly the most obvious difference between wolves and dogs is how much more friendly dogs are.
While wolves are still incredibly wild—and incredibly dangerous—domesticated dogs love nothing more than to be close to their human partners. Even though dogs and wolves share 98.8% of the same DNA and belong to the same species, their personalities are worlds apart.
According to this study, there are three genes in domesticated dogs that cause them to be so friendly. These genes are GTF2I, GTF2IRD1, and WBSCR17.
Interestingly enough, these same genes are affected in people with Williams-Buren syndrome, which causes people to be excessively friendly. Humans who have been diagnosed with Williams-Buren syndrome are missing sequences of genes, including the three listed above.
Before dogs’ friendliness was linked to these genes, researchers assumed that humans selectively bred dogs with endearing qualities. While this is partially true, we now know that wolves may have started the process of domestication on their own through genetic mutation.
It seems as though these three genes in particular directly impact the friendliness of dogs and humans. So how did domesticated dogs end up with these altered genes?
The Domestication Of Dogs
Wolves don’t have the same versions of the genes that cause dogs, and some humans, to be excessively friendly. Some researchers believe the genes changed in wolves as they began to scavenge in people’s campsites. While normal wolves wouldn’t be able to handle being near humans, wolves with these altered genes were able to spend time in the camps, where they received food.
As these genetically-changed wolves reproduced, they passed on their genes to their offspring, increasing the number of friendlier wolves. Humans helped to further the wolves’ domestication by selectively breeding for friendly traits.
Of course, the earliest “friendly” dogs were likely nothing like the pups in our modern world. Dogs have been domesticated for over 30,000 years; with each new generation, the genetic sequence strengthened and the wolves became more and more friendly. After 30,000 years, they have transformed into the loving companions we know today.