Have you ever wondered why dogs are so friendly and affectionate?

You may be surprised to know that scientists have wondered the same thing. To answer the question, scientists from Princeton University and Oregon State University compared the behaviour of a group of dogs with their closest relative, wolves.

The wolves in the study were raised by humans and fully socialized. Even so, the wolves were much more “aloof” than the dogs. The wolves would give a friendly greeting to humans, but then mostly ignore them, while the dogs continued to interact with the people around them.

When the researchers examined the genetic structure of the dogs and the wolves, they found that the “friendly” dogs had variations on chromosomes 6 and 7. Disruption on a gene for a protein called GIF21, which regulates the activity of other genes, was associated with the friendliest, most social dogs.

This same genetic disruption also causes “hyper-social” behaviour in rats.

Perhaps the most interesting fact is that a similar genetic disruption can be found in humans with Williams-Beuren syndrome, which leads to mental disabilities, but also causes the victims to be very trusting, friendly, and affectionate.

It is very likely that early humans kept and bred the friendliest dogs – dogs that possessed the genetic abnormality. These dogs passed on the abnormality to their offspring, giving rise to the modern, domestic dog.

Whatever the reason, it is clear that dogs love their human families, and we love them back!