When scientists speak of behavioral change, they are really talking about learning. And, as far as we know, there are only two mechanisms of learning that animals employ: associative learning and social learning. For a century, Pavlovian behaviorists have argued for the predominance of associative learning. Animals, dogs included, are great at learning associations between neutral events and things that they like, such as food, or things that they don’t like, such as pain. But associative learning cannot explain all of animal behavior. For one, it is inefficient. For an animal to learn associations, it has to actually experience the events. This is a trial-and-error process. By this learning mechanism, a dog would actually have to touch its paw to a hot stove to learn that that is something to be avoided.
Social learning is far more efficient. Many animal species employ social learning. Songbirds, for example, learn their species-specific calls from each other. But besides humans, dogs may be the best of all. By watching other dogs, Fido can learn a great deal. He doesn’t have to burn his paw to learn that the stove is dangerous if he sees another dog (or human) do the same. And, of course, puppies learn from each other and their mother, copying behaviors like pulling toys.
I have often wondered how dogs got so good at social learning. While many animals learn from members of their own species, dogs are one of the few that can learn from other species. Herding dogs, for example, learn by observing sheep and cattle. And all dogs learn by observing humans and other members of their households, just like Callie learned how to open doors. Village dogs, even though they are not attached to specific humans, exemplify this ability for social learning. There is no other way they could keep up with the ever-changing form of human society.
In the hot dog experiment, we found that the meaning of the hand signals had transferred to the caudate—a brain region known to be associated with positive expectations. While a cool scientific finding, it was not really unexpected given what we had known about Pavlovian learning. What was more revealing, and what we never commented on in our academic papers, was all the other stuff going on in Callie’s and McKenzie’s brains. The motor cortex activity. The inferior temporal lobe. Those were the regions that pointed toward a theory of mind, and they were the same regions that popped up in the smell experiment associated with familiar humans.
These cortical regions showed that the dogs might be constructing mental models of our actions. The inferior temporal lobe suggested that they were recalling memories, perhaps what one hand pointing up meant, or the identity of the person associated with a sweat sample. These are the types of mental processes that any sentient being would use on a daily basis. Humans use memories and ascribe meaning to people and actions all the time. Apparently, so do dogs.
Even though we found evidence for canine theory of mind in our experiments, Callie and McKenzie were not exactly the same in this regard. They showed differences in how their brains reacted to the hand signals and to the smells. With only two subjects, it is difficult to draw sweeping conclusions, but I will take scientific license to speculate.
In the hot dog experiment, McKenzie had stronger caudate activation to the “hot dog” hand signal. Strangely, Callie was the food lover, while McKenzie much preferred toys as rewards during training. Because of her great love of hot dogs, I had expected Callie to show the stronger caudate activation. But she didn’t. One possibility is that because Melissa and McKenzie had competed in agility competitions, McKenzie was more attuned to hand signals. I had not taught Callie a hand signal before the Dog Project, which might have put her at a relative disadvantage. Another possibility, which I think is very likely, is a genetic basis.
Even though we thought she was a feist, Callie was more like an adopted village dog. A mutt. McKenzie, on the other hand, was meticulously bred to be a herding dog. Border collies are known for their stares, what the Coppingers refer to as the eye-stalk. Border collies don’t just see with their eyes; they use them to control other species. There may have been much more going on in McKenzie’s brain as she not only interpreted Melissa’s signals but also returned them with her eyes. While I had noticed a flicker of that in Callie when her eyes dilated in anticipation, it was nothing like being stared down by a border collie.
In the smell experiment, though, the pattern reversed. Callie had the stronger response to the familiar human smell. Maybe that was because Callie slept with Kat and me in our bed, while McKenzie slept in her crate. Or maybe the bond between Callie and Kat was stronger than that between McKenzie and Melissa’s husband. Could it be that our dogs tell us more about our human relationships than we tell ourselves? The term therapy dog would take on a new meaning.
The evidence for social cognition in dogs’ brains has important implications for the dog-human relationship. Dogs watch us constantly, even though we may not be aware of it. With furtive glances, they take in their surroundings and form mental models of what we humans are intending to do. It is the humans who are unaware of the dogs. And that is where misunderstandings can arise.
Humans are sloppy creatures. Like the proverbial bull in a china shop, we are oblivious to our body language. We bump into objects. We accidentally step on our dogs’ tails. We emit a constant stream of sounds with frequently inconsistent meanings. It is a wonder that dogs can pull anything consistent out of this barrage of signals. And yet they do.
The whole purpose of the Dog Project was to understand the dog-human relationship from the dogs’ perspective, and the most important thing that we learned was that dogs’ brains show evidence of a theory of mind for humans. This means that they not only pay attention to what we do but to what we think, and they change their behavior based on what they think we’re thinking. They are the Zeligs of the animal kingdom.
Zelig was a fictional character created and played by Woody Allen in his 1983 movie of the same name. Zelig had no personality of his own. Instead, he took on the personality and physical form of people around him. Because doctors thought he was crazy, Zelig was institutionalized in a mental hospital, where he took on the form of a psychiatrist. (His real psychiatrist, a woman played by Mia Farrow, falls in love with Zelig and they eventually run off together at the end of the movie.) Apart from being a terrific film, Zelig is a case study in theory of mind. Zelig’s problem was that he had no sense of self. He had a sense of only others. The sense was so strong that he knew what was in other people’s minds, and he became them.
If dogs are like Zelig, then the form they take depends on the people they live with. If they live with calm, consistent humans, they will pick up on those qualities. If they live with people who talk constantly, without saying anything, dogs will quickly learn that there is no useful information in their chatter. With their social cognition skills, dogs do not need an excess of jabbering. Patricia McConnell, the well-known animal behaviorist, has written extensively about the effectiveness of the less-is-more approach to dog communication. The takeaway is that humans should pay more attention to what their body language communicates than what their mouths say.
Dogs’ sensitivity to social signals also puts a new twist on the old notion of human as “pack leader.” While it is easy to confuse being a pack leader with being dominant, that is a mistake that has harmed more dogs than any other piece of advice.