Quirks and Quarks·QUIRKS & QUARKS

Your dog's mutant superpower is... love

A new study has discovered a genetic link between unusual human super-sociability, why your dog loves pleasing you and why wolves don't.

Why do dogs love humans?

6 years ago
Duration 1:00
Why do dogs love humans?

There is no doubt dogs are humans' best friend, but there has always been doubt about why dogs want to be our friends.

Now, new research has discovered the genetic reason dogs love us. It turns out your dog is kind of a mutant, but a mutant in the furriest, cutest, best friend kind of way.

Guest host Sonya Buyting spoke with Dr. Monique Udell, an animal behaviourist from Oregon State University, who was part of the study.

This interview has been edited for length and clarity.

Sonya Buyting: What is the connection between how dogs love us and them being mutants?

Dr. Monique Udell: So what we've identified is that there are certain genes, that in humans, are associated with a behavioural syndrome called Williams–Beuren Syndrome. And this, in humans, leads to developmental delays, but it also leads to things like hypersociability - meaning excessively friendly behaviour towards both familiar people and strangers. And what we've identified in dogs is that they share some changes along the same genetic region as humans with this syndrome exhibit, that increases their prosocial behaviour. And this is different from their wild counterpart, wolves.

SB: What do you mean when you say prosocial behaviour?

MU: What we see in dogs is that they engage in almost a juvenile type of social behaviour, so they'll go up and greet you, then they'll continue to greet you, and greet you some more. Wolves don't do this. They tend to come up and greet people, if they're if they've been socialized to them, or they'll greet their social companions, and then they'll return back to their normal activities. So they behave much more like you'd expect of an adult greeting another adult.

We did a couple of different behavioural tests with the dogs and wolves to determine their level of sociability.

SB: I can understand how you got dogs from a study but how did you manage to get wolves roped into the study?

MU: The wolves we use are from Wolf Park in Indiana, so they were hand-raised by people from two weeks of age. They're arguably some of the most socialized wolves in the world. And this is really critical for a fair comparison with pet dogs because we really wanted wolves that were as prosocial towards people as possible. Yet we still find these really striking differences.
A socialized wolf briefly greeting an unfamiliar experimenter (Monty Sloan)

SB: The genetic similarity between the dogs and people with Williams-Beuren Syndrome that you found to be associated with prosocial behaviours, what does that genetic region do?

MU: There are areas associated with Williams-Beuren Syndrome in humans, with either deletions or insertions, along these genetic areas, that have led to hypersocial behaviour in people with this syndrome.

SB: This syndrome in people, as I understand, is associated with oxytocin, which is the "cuddle hormone." Does oxytocin have anything to do with us?

MU: It may. It is true that when two people are bonding, you often see oxytocin levels increase. You see that same sort of relationship between dogs and people. And so this might be related to some of the changes that we've identified.

SB: Not to anthropomorphize, but we really do love each other...

MU: Yes, absolutely. I think it's not even anthropomorphizing. There are indicators that there's a similarity in our social response towards each other. And you might describe it as love.

SB: How do you think dogs acquire this trait of sociability?

MU: If you think about early on in their evolutionary history, where they're diverging from wolves, it may have been that this was just a natural development of something like Williams-Beuren Syndrome in this population of wolves, so wolves that were a little bit different genetically that resulted in these changes that ultimately led them to be maybe a little less wary of people or even a little bit more prosocial towards others in their environment. And this likely led to them being able to capitalize on resources that were around human environments, so maybe to be more effective scavengers with waste.

Then over time, it was likely a trait that was actively selected for, so once these animals got integrated more into human communities where they were actually potentially being bred or their breeding was being more controlled, you could see where having animals that are excessively friendly and maybe a little bit less of a threat would have been a desirable quality. And so likely, it was a combination of natural and artificial selection.​