Dogs are pretty smart. They can have huge vocabularies, they can infer meaning in the growls of other dogs, and they can effortlessly figure out if other dogs want to play or fight with them. But their intelligence might be limited to the social domain; indeed, while they outperform chimpanzees in social tasks, chimpanzees outperform them in many other tasks. And they might have developed their impressive social skills as merely an accident of natural and artificial selection.
Previous research has shown that dogs can use lots of different forms of human communicative signals to find food, and they can also inform humans of the location of hidden food, by looking back and forth between that human and a second location. But what is it about dogs that allows them to comprehend and invoke human social communication?
Hungarian canine cognition researcher Adam Miklosi has written that "the genetic divergence of the dog from its ancestor was [presumably] accompanied by important behavioral changes that could have a genetic basis because of a selection pressure for dogs that were able to adapt better to the human social setting." If that was the case (and it probably is), then it follows that while some natural variation in performance on a given task requiring the use of human social communicative cues may be seen in wolves, it should be a lot stronger in dogs. Comparing wolves and dogs is the obvious way to address this question, but wolves and dogs differ both in genetics as well as in environment. While most dogs are raised in houses as pets, most wolves live in the wild, or in zoos, or occasionally in conservation parks. Adam Miklosi and colleagues, of Eotvos University in Budapest, took advantage of a very unique situation. Thirteen wolves were hand-raised and socialized in human homes, just as dogs would be. By raising both dogs and wolves similar contexts, the effects of rearing environment can be minimized, allowing the researchers to infer that differences in behavior are more likely due to genetic differences.
In the first experiment, four of the socialized wolves were tested in the standard two-way hidden food task. The experimenters would hide food in one of two containers, and then using one of three gestures, they would indicate to the wolf the location of the food: distal pointing (the human's finger is about 50cm from the container), proximal pointing (the human's finger is 5-10cm from the container), and making physical contact with the container with the index finger.
In addition to the overall analysis, which indicates that the wolves performed significantly above chance one condition, they looked at the performance of each wolf individually. For each wolf, performance on the distal pointing condition was at chance, but one wolf increased his performance such that by the end of the experiment, he chose correctly on 80% of trials. All individuals performed significantly above chance on the touching condition, as is evident in the aggregate data above. In the proximal pointing condition, two of the four wolves consistently performed above chance. Taken together, it appears that given dog-like rearing, wolves can learn something about human social communication. Despite this, compared to similar studies with dogs, the performance of the wolves was worse and more variable.
To succeed in the two conditions which resulted in the highest number of successful trials, the "touching" and "proximal pointing" conditions, the wolves only needed to attend to the immediate space around the container. This may explain the higher success in those conditions. In the distal pointing condition, they would need to attend to two locations in space: the container as well as the human experimenter. If wolves do not pay attention to the human, they would be unable to determine the direction that the hand is pointing, and the task could become, in a way, unsolvable.
In order to investigate this a little further, the experimenters designed a second study, involving two behavioral tests: bin-opening and rope-pulling. Upon successful completion of either task, the individual received a piece of meat as a reward. Both pet dogs as well as the socialized wolves were allowed to learn how to solve either problem during a training phase. Both groups of animals were equally able to solve the task, and did so following an equivalent number of trials, suggesting similar motivation. Once the individuals had learned the task, they were presented with what appeared to be the same task, but was unsolvable. The key variable was where, how quickly, and how long the individual would look after attempting and failing to complete the task.
In both tasks, dogs looked back at humans earlier than the wolves did, and for greater duration. In the bin-opening task, specifically, dogs spend more time overall gazing towards the human experimenter, and did so significantly earlier than the wolves did. In fact, only two of the seven wolves tested looked towards the human at all during the insolvable trial, while five of seven dogs did so. On average, the dogs began to look towards the human experimenter after one minute of attempting to solve the task, while the wolves all but ignored the presence of the experimenter. This is not to say that wolves are not intelligent. In fact, wolves can be quite intelligent, they just don't care too much about humans, and therefore perform poorly in tasks that require them to engage socially with us.
Experiment one demonstrated that under dog-like rearing conditions, wolves could understand some human social communicative gestures. However, experiment two suggested that only dogs regularly attempt to initiate communication with humans, by attempting to make face or eye contact with them. Based on the result of the second experiment, the researchers inferred that the relative failure of the socialized wolves to succeed in the first experiment was due to their unwillingness, or put more neutrally, their disinterest, in looking at the humans. They also inferred that, since the wolves and dogs had similar upbringing, the dogs' preference for looking at humans was due to a genetic predisposition. Further, they speculated that,
...one of the first steps in the domestication of the dog was the selection for "human-like" communicative behaviors. As we found some behavioral variability in our wolves, this species might have been predisposed for successful selection to take place. Since in humans taking up eye/face contact is understood as initialization and maintenance of a communicative interaction, we suppose that the corresponding behavior in dogs provides the foundation on which developmentally canalized complex communicative interactions can emerge between man and dog.
What does this mean exactly? Selection (whether natural or artificial) occurs because there is natural variation in a given trait in a population. Certain environmental constraints make it such that certain variations of a given trait are more adaptive than others. In the wolves, for example, at least some portion of the population must have displayed an ability to understand and initiate communication with humans. These individuals would be most adapted to life with humans and would therefore be more likely to breed. What would eventually emerge was the domesticated dog.
Dogs' social skills could therefore be encoded in their genes. Canalization is a process wherein genetics limits the variation in possible developmental outcomes, regardless of environmental specifics. In the passage quoted above, Miklosi and colleagues suggest that the near universal ability of dogs to engage socially with humans is the result of such a strong genetic predisposition that even differential rearing environments would not significantly alter the outcome. In a sense, while wolves may have limited abilities to socially engage with humans, domesticated dogs are specialized for the task. And this would suggest that dogs are a uniquely suited species to help us understand our own human social cognition, whether we are interested in investigating attachment between individuals, cooperation, social learning, or even pedagogy.
MiklÃ³si A, Kubinyi E, TopÃ¡l J, GÃ¡csi M, VirÃ¡nyi Z, & CsÃ¡nyi V (2003). A simple reason for a big difference: wolves do not look back at humans, but dogs do. Current biology : CB, 13 (9), 763-6 PMID: 12725735
Interesting article but why the bizarre counter-intuitive y-axis on the 1st graph? Whenever I see that sort of thing it annoys the heck out of me.
Schwaggy schwaggy schwaggy schwag.
Without a detailed and validated cognitive model, this sort of thing is really hard to interpret.
In canids, eye contact is often interpreted as challenging or aggressive. (Too many humans don't know not to look a dog in the eye---what we think of as open and friendly is something very different to a dog.)
The ability of domestic dogs to learn to look at their owners, and not freak out when their owners look right back, may be genetic, but only increase "intelligence" of any sort in an odd sort of way. To get along with humans, dogs may have evolved to be a bit dog-autistic and not read the obvious dog signals the dog-obvious way. Trading one simple variable bias for another simple bias may have lots of downstream effects that look like differential "intelligence" within an oddly constrained range of tasks.
A plausible just-so story along those lines is that domesticated dogs' social intelligence is stunted, so that they remain puppy-like, and less engaged with serious dominance issues. Puppies get a lot of slack about things that would count as aggression if done by an adult dog among adult dogs, and can play more in ways that would get an adult dog in big trouble.
Maybe domestic dogs are just perpetually rather clueless about being "challenging" and that has a benefit when dealing with non-dogs.
What I really want to know is why, if dogs are really so well-suited to interacting with humans in human terms, they still get away with not wearing pants.
Ob. caveat: I'm not an ethologist or any other kind of expert on this stuff. (And on the Internet nobody can tell if you're a dog, or not wearing pants.)
By the way, I'm curious what would happen if you trained wolves and domestic dogs using a pointing device that was not attached to an animal such as a human, with which they didn't have a dominance relationship. Would wolves be just as adept at looking back at the pointer, if you removed the conflict with a very specific social instinct?
Is understanding such pointing even a matter of social instincts, aside from that? Would a non-social pointing thing just work better?
Hmmm... on reflection, my last comment sounds maybe silly. Pointing is an instinctive dog behavior, right? Wolves "point" for each other (in some sense) in the wild, when hunting in packs, right?
On the other hand, it's not clear to me that dogs understand humans' pointing with fingers in at all the same way---it may not take advantage of the same social instincts, which may only be triggered by body-and-gaze alignment, quivering tail, etc.---so the question stands.
To get along with humans, dogs may have evolved to be a bit dog-autistic and not read the obvious dog signals the dog-obvious way.
I'm not a dog, and I'm wearing pants.
Some friends of mine have socialized wolves. Dogs don't seem to have problems "reading" them, and they don't seem to have any problem "reading" dogs. Anecdotes are not data, of course.
As mentioned earlier, a non social pointing would be interesting to see - perhaps a light going on, or somthing that attracts attention to the correct container withoug it coming from a living organism. This discussion also reminds me a bit of my Master's thesis about visual attention structure in a captive wolf pack. In that study it was clear that pack members were orienting their heads and bodies toward the highest ranking female. Who is going to be worth watching more - the important members of your social group or some other species?
A friends dog came in from outside clearly looking for her master. I pointed down the hall to where he was and she took off down the hall to him. It seemed to me like clear communication on the part of both of us.
My uncle was federal predator control agent on the Texas-Mexico border. He told me the most difficult predators to control were feral dogs, because they understood humans.
Interesting article but why the bizarre counter-intuitive y-axis on the 1st graph? Whenever I see that sort of thing it annoys the heck out of me.
Posted by: NoAstronomer | August 31, 2010 12:17 PM
You're doing better than me. I have no idea how to read that figure.
I would like to know more about the rearing of these "socialized wolves", including age of the animals at time of testing and exact methodology used to rear not only the wolves but also the dogs use in this experiment. It is well known that by dog trainers that there is considerable variability in the ability of young dogs to become socialized with humans outside their primary "owner", and I would be curious to know if the experiment results differed for dogs and wolves tested by a neutral tester or by their primary "owner".
Since the word "wolf" carries considerable emotional and psychological charge, I also wonder whether it is possible to truly raise a "wolf" in the same conditions as a dog. Owners of certain dog breeds carrying a mythology for toughness or viciousness (German Shepherd Dogs, for example) are more likely to experience difficulty socializing their young dogs to strange people outside the owners immediate family. Were the socialized subject wolves raised in a double blind situation to account for this?
I have had dogs all my adult life, usually two at a time. Their "communication" abilities have varied greatly. I usually end up using dog signals rather than the other way around. One thing I have noticed that doesn't vary is a dog "guilt" reaction to any stern or accusatory tone of voice. The problem is, both dogs react even if only one is addressed. Pack reaction?
Interesting that you mention the guilt response! I've just read something (now, if only i could remember where i read it) that suggested that the guilt response is not actually because they know they've done something wrong - rather its a response to YOUR response to their wrongdoing - a social reaction!
sort of like when you scold a child and they give you that big frown (which of course prompts the parent/caregiver to ease up on the scolding - unless you're me, I say "that might work on your mother but it won't work on me!")
You may be right Jason: it works on me! I feel badly for scolding the innocent dog and lighten up. One of the dogs I have now usually is the culprit: her over-the-top response always gives her away - (dangerous ground here!) I would even say her response is sarcastic! She rolls over to be submissive, but then bangs her tail on the ground furiously - will even bare a few teeth. Her mea culpa is so insincere that I have to turn away so she doesn't see me crack up. I know ...... I'm cuckoo.
I wonder if a wolf's age and dominance/status in relation to the human experimenter .and whether it's been raised in a setting with humans or not, might effect how that wolf responds to communications signals. I can believe a wolf who young and/or has lower status might find that paying attention and responding to signals from a human or an other wolf depending on that wolf's or human's percieved status, that indicating that food is available for instance would not be more than just being able to figure out what the human is trying to say.
I think dogs are focussed on what they want and can easily figure out how to get it. We try so hard to "communicate" but what they respond to are concrete objects: food, food, and more food. And actions: putting on one's shoes, picking up the keys, grabbing the leash - it's all so obvious! We don't really need to say 'truck' or 'walk' or 'let's go' - that's just for us.
Owners of certain dog breeds carrying a mythology for toughness or viciousness (German Shepherd Dogs, for example) are more likely to experience difficulty socializing their young dogs to strange people outside the owners immediate family.
The German Shepherd owner in me immediately wanted to lead to the defense of the breed, I wouldn't say that's their reputation at all, but it's also not the point.
For me this study presents an interesting overlap with the "dog intelligence" studies, which in some ways tested very similar things. In order to rank the intelligence of dogs the people who performed those studies tested the number of repetitions that were necessary before a dog understood a particular command.
The studies showed the dogs most likely to follow commands and to quickly understand new commands are those dogs that have been bred to be "working dogs" and certain kinds of retrieving dogs. German Shepherds, Rottweilers, Dobermans, various herding dogs and retrievers all fall into the top category.
I'm not sure exactly what connections you can draw, but it's a pretty interesting correlation between the results about "social intelligence" and dogs that were bred for that sort of task.
I take exception to the title of the paper. Over a quarter of the wolves sampled looked back at the humans, while less than three quarters of the dogs looked back at the humans. Can you really claim scientifically that A doesn't do B when 28% of known A does B?
What Really Prompts The Dog's 'Guilty Look'
Kai, it seems to me that Horowitz begged the question because he set up the experiment so that the dog owners already knew, or thought they knew, that their dog had misbehaved and immediately began scolding. But this doesn't explain the experience I and many other dog owners have had, where we only realise the dog has misbehaved _because_ it's looking guilty. So we look around until we discover what it's done. To my mind that can only be explained by the dog anticipating the owner's annoyance, presumably via prior experience.
But, Steve P (at comment 17), what they are saying is NOT "dogs do this, wolves never do". They say "Dogs are really good at looking at people for cues, and some wolves do a bit, and some don't do it at all, so maybe dogs developed from wolves who were good at lookign at humans and reading their signals."
That is the *point* of the piece. Are you multitasking? I sometimes make those mistakes when multitasking.