Dogs are particularly good at tasks that involve communicating or cooperating with humans, which has led some researchers to speculate that they are really good at solving social tasks, more generally. For example, dogs can figure out where a human's attention is, are really good at picking up on eye-gaze and finger pointing cues, distinguish among different individual humans (by contrast, humans are really bad at distinguishing among different individual monkeys, for example), and at least in one outstanding case, are capable of "fast mapping."
Relative to non-human primates, domestic dogs indeed seem to have exceptional social skills. For example, previous research has demonstrated that dogs are able to use human social cues to find hidden food while non-human primates do not. Furthermore, cross-sectional studies of dogs and puppies of different ages, as well as longitudinal studies which track the development of individual puppies, have indicated that dogs do not require extensive exposure to humans to skillfully use those cues (though training enhances their skill). By contrast, wolf pups do require extensive exposure to humans to be able to extract meaning from human social cues such as eye-gaze and finger-pointing. So, while both dogs and wolves are able to understand human social cues, the domestication of dogs seems to have selected for this trait and allowed it to emerge early in development without much experience.
But these studies of social cognition in dogs have had one common theme, which is that they all tested social cognition in the context of a communicative-cooperative task. But do dogs' social skills extend beyond this narrow context? In non-communicative or non-cooperative social tasks, are dogs' social skills otherwise unremarkable? The distinction is not trivial; social information comes in various forms beyond explicit communication. For example, various non-human primate species are known to alter their behavior when trying to steal food from a human, according to whether or not that human is watching them. This is surely a social problem, but one devoid of explicit communication or cooperation.
Two researchers with whom the regular reader of this blog should now be familiar, Victoria Wobber (who ran the bonobo testosterone study I mentioned in the review of Bonobo Handshake) and Brian Hare, wonder to what extent dogs can reason about the social world more broadly. Specifically, would their impressive social skills persist in a task that did not involve cooperative communication? They compared dogs and chimpanzees in two versions of a reversal learning task: non-social and social.
The reversal-learning task goes something like this: you present the individual with two containers. In one container there is a reward (like a peanut or a dog biscuit), and in the other container, no reward. If the subject chooses correctly, the reward is given; if not, the reward is revealed in the alternate location but is not given. The reward is always going to be found in the same location, so after a few trials, the participant should learn which container to choose to receive the reward. Then, once it becomes clear that the participant has learned the task (in this study, 84% accuracy), then the rewarded container switches. How quickly does the participant learn to inhibit the previously-correct choice, and begin choosing the alternative container which now contains the reward?
In the non-social condition, the reward was hidden underneath cups or bowls. The experimenter takes a treat, hides it under one of the bowls, and sham-hides it under the other bowl. Then the experimenter backs away and stares directly at the individual instead of at either of the bowls and the individual is allowed to choose.
In the social condition, instead of cups or bowls, human experimenters hid the rewards in their hands. Both experimenters went to the box of treats: the first took one and hid it in her hand, and the second only pretended to take one and hide it in her hand. Then both experimenters approached, reached out and offered their closed fists to the participant. As in the non-social condition, the participant chooses by pointing or approaching one of the individuals. This task requires that the participant form an association between one individual human and the potential reward, but does not require the participant to interpret any cooperative-communicative cues. Compared to the non-social task, this task is highly social: the participant must use social information about an individual's previous behavior to succeed.
It is well-known that in humans, placing an otherwise non-social problem in a social context increases performance. It is therefore possible that chimpanzees and dogs may be better able to learn when identical information is presented in a social context. Wobber and Hare describe their predictions in this way:
If neither species showed a different between the two contexts, this would suggest that the ability to inhibit prior learning is independent of the stimuli being learned. However, if chimpanzees showed increased performance in the social task, this would create two alternative outcomes for the dogs. If dogs' exceptional social skills extend beyond the use of cooperative-communicative contexts, they should show relatively more skill in the social reversal learning task than the non-social task. If, however, their skills are limited to interpreting human signals, they should show no distinction between the two tasks.
Critically, the goal here isn't two compare chimpanzees to dogs. The predictions concern within-species differences between the two tasks. In that sense, the chimpanzees serve as a control for the dogs. If the chimpanzees do not show a task-dependent difference, the data from the dogs can't really be interpreted. However, if the chimpanzees do show a task-dependent difference, then the data from the dogs is interpretable in terms of the importance of the social context.
Twenty-two chimpanzees participated as well as twenty-four dogs. Each individual participated in either the social or non-social condition, but not both. The chimp research took place at the Tchimpounga Chimpanzee Sanctuary in the Congo Republic (chimpanzee congo, not bonobo congo), and the dog research took place at the Max Planck Institute for Evolutionary Anthropology, in Leipzig, Germany (all dogs were pets).
First, how quickly did the participants learn the initial association, in either condition? For both species, there were no differences between tasks in how quickly they were able to form the initial association.
Next, how did the participants do in the second part of the experiment, after the reward location had been reversed? There was a significant difference between conditions for the chimpanzees, with chimpanzees in the social condition performing better. There was no significant difference for the dogs.
Furthermore, when comparing the first ten and last ten trials of the reversed part of the task, it is clear that while the dogs in general improved throughout the course of the experiment, there was no distinction between the two conditions. In contrast, for the chimpanzees, there is a clear difference between conditions: they improved over the course of the experiment in the non-social task, but were near ceiling the entire time in the social task.
Taken together, the data suggest that while chimpanzees were able to inhibit their learned response in the social condition, the dogs were unable to inhibit their learned response in either condition. The social context allowed the chimps to quickly alter their behavioral response. In contrast, the social stimuli devoid of communicative-cooperative information, was not helpful for the dogs. This supports the hypothesis that dogs' exceptional social abilities are specific to contexts involving cooperation and communication with humans, not that dogs are more skilled with social problems more broadly. By contrast, chimpanzees were more successful in the social condition than the non-social condition. While dogs may be more successful when given communicative-cooperative information by humans, chimps are clearly more successful than dogs in the absence of such information.
What allowed the chimpanzees to excel in this task? It is known that chimpanzees (as well as rhesus macaques and human children) keep track of who their friends and enemies are, so it may be that they formed "reputations" for the two human experimenters in the social task. It is not yet known whether dogs do this as well.
Another possibility is that the presence of the two human experimenters in the social task was too distracting for the dogs to really perform to their potential in this task. However, neither the chimps nor the dogs differed between conditions in terms of their ability to learn the initial association, suggesting that the task was a valid measure of learning, and that both species were sufficiently motivated.
So overall while the data don't completely contradict the hypothesis that dogs have superior social problem-solving skills overall, it does suggest that their domestication has particularly enhanced their problem-solving skills in communicative-cooperative contexts. More specifically, even if they are unusually competent with social tasks in general, they seem to be especially good at social tasks involving communication or cooperation with humans.
Wobber, V., & Hare, B. (2009). Testing the social dog hypothesis: Are dogs also more skilled than chimpanzees in non-communicative social tasks? Behavioural Processes, 81 (3), 423-428 DOI: 10.1016/j.beproc.2009.04.003
I don't know what kind of dogs you used in this experiment, but I have a beagle, and if you are assessing how well a beagle "learns" which hand or container has a treat, you have to allow for the fact that he can probably smell the treat. The PetSmart store offers free sample dog biscuits at the register. I often put one in my pocket and forget about it. After I get home, I'll sit down on the sofa and Darwin will jump up next to me and start to sniff me and get excited. If I do nothing, he will nuzzle my hip looking for the treat. I don't know much about how his brain works, but his nose is excellent.
Great post, fascinating paper. I wouldn't have seen it without your blog - thanks.
I take issue with one thing you write, though:
It is known that chimpanzees ... keep track of who their friends and enemies are, so it may be that they formed "reputations" for the two human experimenters in the social task. It is not yet known whether dogs do this as well
It has been known since the time of Plato, who wrote in The Republic: "a dog, whenever he sees a stranger, is angry; when an acquaintance, he welcomes him, ..."
This is particularly interesting, considering that wolves and dingoes -which lack the social talents of domesticated dogs- actually are "smarter" than domestic dogs at non-social tasks. The evolutionary pressure on dogs has thus produced extraordinary results on social skills despite a more impoverished brain.
Are there breed differences in social skills or general intelligence? I (and any other dog owner, I'm sure, particularly any that go to the dog park) commonly hear that Breed X is easier/harder to train, or smarter/dumber. Are these often anecdotal assertions backed up by data? For instance, it's easy for me to say, well, I have a dog that's stubborn as hell and refuses to come when called if there's something interesting to smell and another that's very attuned to her name and 'come' but refuses to learn not to jump on people. Can you actually say one personality is due to hound genes and one to boxer genes (or possibly kangaroo), or is it all within normal variation between any two individuals, between breeds or within them?
This reminds me of a piece of research by A. Horowitz ("Disambiguating the âguilty lookâ: Salient prompts to a familiar dog behaviour") that looked at whether dogs can understand when they should be "guilty" enough to give genuine "guilty looks". Turns out they probably can't.
Thanks for the good post!
Great study, thanks for posting the findings!!
@1: In other studies, it has been shown that domestic dogs do not use olfactory information to find food and rely on human social interaction. This is not to say that they don't have a good sense of smell (certainly, some breeds were specifically bred for that purpose), just that they might not use it. And then, your dog may be an exceptional anecdote, but not data.
@2: A dog can certainly distinguish among individual humans, as I wrote, particularly acquaintances from strangers. But this is different from forming lasting reputations and predicting future behavior based on prior behavior.
@4: I've heard the same anecdotes as you. We do know that there's some data on e.g. breed personality, but I'm not sure about learning style. If you told me that personality and learning style were correlated, I'd believe you. I'll look around. My guess would be that, like most things, you'll find more within-breed variation than between-breed variation. Good question!
Great post. Wouldn't have seen the paper without your blog. Thanks!
I always find these kinds of intelligence tests interesting and I too have heard that wolves, while similar to dogs in so many ways, lack the ability to interpret the non-verbal cues that dogs do. I've seen the videos that exhibit this, with the wolf (adult wolf, I should add), whose intelligence is not doubted, just not seem to get what the human is doing by pointing or looking at the intended object, or at least not thinking it was meaningful, and I've always wondered, since dogs possess so many trait which in wolves are associated with their young, if anyone ever conducted these same experiments with young wolves who have yet to become invested in their packs instinctive social dominance drive. It would seem that an adult wolf would not benefit from being distracted by where it's packmates were staring unless there was also some other cue, but a young wolf would benefit from this kind of intelligence so that it could learn what it's other packmates were trying to convey as it learned how to be a wolf in their social structure and thereby rise and bring benefit to the pack.
I had read that dogs cannot attribute motivation to other creatures, but my experience suggests otherwise.
Once, when I was playing ball alone with my dog in the park, she noticed another dog approaching from off in the distance. She took her ball, placed it by the exposed roots of a tree and looked hard at it, seeming to memorize its exact location. Before the other dog came near, mine had walked away from her ball, as if intentionally keeping it inconspicuous to the stranger who might (if like my dog) be tempted to steal it.
Jason Goldman wrote this:
@1: In other studies, it has been shown that domestic dogs do not use olfactory information to find food and rely on human social interaction.
I'd wonder about those studies. It seems such a maladaptive behaviour to have a good nose and not use it to find food. And anyway, I could tell you about the time my dog ate the wrapped chocolate bar under the christmas tree which the humans didn't know about.
But more seriously, I rather suspect that you left out some qualifications there. There may be circumstances where dogs don't use their noses to find food. Perhaps in a well-designed experiment they don't or can't, but I can hardly imagine that the blanket statement is true under all circumstances.
Is this saying that domestic dogs have developed dependent personalities and require us to stimulate or guide their brains, which have become lazy? Well I think they are no longer a fully canine creation - they've surely learnt a lot from us, and maybe lost a lot by intra-species living arrangements. Our need for them as hunt aids and protectors has kind of diminished - creating a lot of redundancy. But my dog certainly reads me like a book, senses my moves before me.
I don't know much but searched the dog IQ subject out if an emerging curiosity as to why some dogs I know are smarter as well as more prosocial and balanced than many people I know. Proof - a person with a diploma and obvious need to feel superior alleged to me dogs don't think, but only run on instinct! Well mine have often formulated complicated plans and solved complex practical and social problems.
One dog (an honest tending shepherd/greyhound) would eye up food left in an outside sleep out all day - then when someone got home from work would either lead us to it and seek consent to devour it - or bring it in its wrapper to the main house and request permission to devour it. A less honest more dare devil dog I had (GSP) figured out the day that he local Drs wife stocked up at the butcher and would hide in her bushes till her car pulled in, then as she too the first joint of meat in her house he would leap in the boot of her car and get a large meat cut eg leg of lamb, and bring it home as an offering to our household.
This occurred for months before we discovered the meat source, when we heard via gossip that the elderly Drs wife did not know who stole her meat, but figured it was a hungry person, so now allowed for a bit extra in the weekly purchase...
Funny - the dog wasn't hungry nor us the recipients of her contribution. Seems she just needed to contribute. Idols were another sign of civilisation. The dog had a sculpture of a dog it nestled up to in times of crisis like guy fawkes, and revered an older female - to the point of making long leisurely daily visits to the older dogs grave for a few months when she died (without any thought of digging as we feared), and being very distressed by the corpse (alarmed, skittish and repulsed - showing whites of eyes in horror at the older dogs fate) and by it's burial (depressed - crying tears, and turned away refusing to watch). In contrast the dog was not too concerned at my Mothers inanimate body, also lying in state alongside the beloved older dog (both killed together on a car crash).
In fact touching either after death whom he'd usually be all over was taboo to him and he kept 2 metres distant - could be a fear death is contagious? Sure was understood.
I am a dog trainer by profession and a behavior junkie. One of our dogs has already participated in Dr. Hare's study. Our other dog will participate later this month. It was fascinating to watch. I do believe that there is some differences with breeds, in that some are bread to work with people (the herding breeds) and some are bread to work alone. That being said both of our dogs are Australian Shepards and I'm certain that the results from the tests as I observed them will be very different between these two dogs of the same breed.