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Finally, after two years, the Dog Project had begun to find clues to why we love dogs so much and how dogs became who they are. Eventually, our results might even explain why dogs and humans came together thousands of years ago. The brain data pointed to dogs’ unique interspecies social intelligence. In answer to the question “What are dogs thinking?” the grand conclusion was this: they’re thinking about what we’re thinking. The dog-human relationship was not one-sided. With their high degree of social and emotional intelligence, dogs reciprocated our feelings toward them. They truly are First Friend.
Throughout the world, the two most popular pets are dogs and cats, and both are descended from predatory species. It seems odd that the first animals that humans supposedly domesticated were hunting animals. You would think that it would have been much easier for prehistoric humans to take in more docile species. A common explanation for this is that dogs helped humans hunt while cats caught vermin. While plausible, this theory assumes that humans domesticated animals because of their usefulness in survival.
The results from the Dog Project suggest a different explanation. While the caudate activation in the dogs’ brains shows that they transfer the meaning of a hand signal to something rewarding like hot dogs, the other brain regions activating point toward a theory of mind. Our results support a theory of self-domestication based on dogs’ superior social cognition and their ability to reciprocate in human relationships. Moreover, these interspecies social skills evolved from dogs’ predatory past.
Apart from humans, strong evidence for theory of mind has been found in only monkeys and apes, which have social cognition for primates but not necessarily other animals. Dogs are much better than apes at interspecies social cognition. Dogs easily bond with humans, cats, livestock, and pretty much any animal. Monkeys, chimpanzees, and apes will not do this without a lot of training from a young age. And even then, I would never trust an ape.
The different types of social cognition may be a result of the different diets of the species. Apes eat fruits, grasses, seeds, and sometimes meat. Like humans, they are omnivorous. Dogs (and cats), on the other hand, are mostly carnivorous. This means that dogs’ ancestors, the wolves, had to hunt their prey. Apart from humans, primates do not depend on meat for a substantial part of their diet.
Hunting is hard. It is not as simple as waiting for prey to wander by. Predator species must outsmart their prey. To some extent, this means that predators must get in the mind of their prey. A lion, for example, stalks a gazelle by anticipating what it is going to do, but the gazelle only reacts. All predators, whether they hunt alone or in packs, had to evolve an interspecies theory of mind to be successful. The brain-imaging results suggested that through evolution, dogs somehow adapted their ancestors’ skills in reading the mind of other animals from a predatory capacity to one of coexistence.
Around twenty-seven thousand years ago, a subspecies of wolves domesticated themselves and became dogs. During this period, the ice sheets had reached their greatest extent, stretching as far south as Germany in Europe and New York City in North America. The ice sheets would have pushed humans who had previously migrated north to move south again. The wolves, who were well adapted to cold climates, also would have moved south following the ice sheets. As a result, both humans and wolves probably came into contact with each other more frequently.
Why wouldn’t they have eaten each other? Perhaps they did. But more likely, a few wolves realized that they could hang around humans. Some researchers have suggested that the wolves survived by scavenging from human leftovers. However, John Bradshaw has pointed out that wolves require a prodigious amount of food, and it is unlikely that a wolf could have survived exclusively off human garbage. Others have suggested that wolves helped humans hunt. This might have been possible, but even modern dogs need to be trained to help the hunter. And wolves are not nearly as trainable as dogs. Moreover, dogs appear almost nowhere in prehistoric cave art that otherwise depicts human hunting activity.
The results from the Dog Project, however, support a much simpler theory. Because wolves were predators, they were already well evolved for intuiting the behavior of other animals, which meant that wolves had a high level of interspecies social cognition, perhaps even a theory of mind. For wolves used to hunting, it would have been a trivial mental feat to learn the habits of humans. If humans fed them, it would have been simply because they liked having them around, not because wolves provided any survival function. Anthropologists have long known about the universal human tendency to take in animals as pets. Everything from reptiles to birds to mammals. In almost all cases, pets provide no useful function other than it makes humans feel good.
It is not hard to imagine a nomadic tribe of Ice Age humans ru
This scenario, however, would not result in any physical changes in the wolf, at least not for a long time. It is unlikely that an individual group of humans could have supported more than one wolf. As a result, there would have been no opportunity for the wolf to breed with other like-minded wolves. I suspect these “one-off” domestication events happened sporadically throughout the period from twenty-seven thousand years ago until about fifteen thousand years ago. Only when humans stopped being nomadic and stayed in one place long enough to span the reproductive cycle of the wolf did physical evolution start to take off, and the wolf morphed into the dog. The remaining wolves—those who wanted nothing to do with humans—gave rise to the wolves we know today. Modern wolves must represent the opposite end of the canid spectrum from dogs.
The defining trait of dogs, therefore, is their interspecies social intelligence, an ability to intuit what humans and other animals are thinking. Wolves do this to hunt prey. But dogs evolved their social intelligence into living with other species instead of eating them. Dogs’ great social intelligence means that they probably also have a high capacity for empathy. More than intuiting what we think, dogs may also feel what we feel. Dogs have emotional intelligence. Just like people, if dogs can be happy, then surely they can be sad and lonely.
Throughout the Dog Project, I had been struck by how perfectly dogs and humans complemented each other. Humans, even with our powerful brains and capacity for abstract thought, are still slaves to our emotions, which dogs will pick up on and resonate with. And the most powerful emotion of all is love. Despite the complexities of human relationships, the fundamental attribute of love is empathy. To love, and be loved, is to feel what another feels and have that returned. It really is that simple. If people do this with each other, it seems perfectly natural for us to do it with animals. People become intensely attached to their pets. Every day, on my way to work, I pass a professional building with a sign advertising grief counseling for pet loss. It is not an exaggeration to say that for many people, their pets are their primary relationships and that they love their cats and dogs more than people. This is why it hurts so much when we lose them.