Journal Article: Does the Owner/Dog Bond Facilitate Canine Learning?

Title: Learning and owner–stranger effects on interspecific communication in domestic dogs (Canis familiaris)

Authors: Angel M. Elgier, Adriana Jakovcevic, Alba E. Mustaca, Mariana Bentosela

Published: December 2008 in Behavioural Processes

General overview:

These researchers were interested in how a dog’s relationship to its owner (which has been described in previous studies as a bond attachment that is similar to that of infant and parental figure. Specifically, the authors were interested in how the processes of extinction (the disappearance of a learned behavior) and reversal learning (learning to do the opposite of a human social cue) would be affected by an owner’s presence or absence. The 13 dogs that were enrolled in the study were randomly assigned an experiment (extinction or reversal) and whether the experiment would be conducted by the owner or a stranger (owner group or stranger group). Then, the authors trained 13 dogs in their lab to seek a treat that was hidden in one of two identical opaque containers that was pointed at by a human standing in the middle of the two containers. After this “acquisition phase”, the dogs were then given their predetermined experiment. In the extinction experiment, neither container had a treat and a “success” for an extinction experiment achieved when the dog did not seek either container within 15 seconds of the point cue. In the reversal experiment, the treat was in the container that was not being pointed at by the human experimenter and a “success” for this experiment was achieved when the dog immediately chose the container that was not being pointed.

The authors found that owner group dogs were much slower to “learn” in the extinction experiment than the stranger group dogs, and that owner group dogs learned the reversal behavior faster than dogs tested with the stranger group dogs. In explanation for the relative poor performance of the owner group dogs in the extinction experiment, the authors hypothesized that the owner group dogs might be more obedient to owners or likely have experienced intermittent reinforcement to their owner’s social cues (resulting in a much more reliable behavior that took longer to “unlearn”). In regards to the better performance of the owner group dogs in the reversal experiment, the researchers hypothesized that an owner’s presence may facilitate learning on the dog’s behalf due to reduced stress. Obviously, however, none of these hypotheses fully explains the results of this experiment.

My comments:

Let’s start off with what I thought was well done in this paper. The data presentation was great: there was a table with demographic information about the dogs (although it did not feature spay/neuter status) as well as a table listing which dog was assigned to which treatment groups and the number of trials each dog took to achieve extinction/reversal learning. The authors also supplied a bar chart of results, which neatly described their findings.

One quibble I do have with this paper is that it is probably the most poorly written research article that I have ever read. All of the authors are from organizations in Argentina and I suspect that the paper was originally written in Spanish and translated very poorly. For example, there were several instances of “to verb” rather than just “verb“, as well as some vocabulary that doesn’t make sense to me (specifically, the use of the word “ontogeny”, which refers to the fetal development of an organism). But as I’m not in the field of applied animal behavior, perhaps I just don’t understand the use of the term in this context.

Unfortunately, I also have some major concerns with the actual experiment procedures. First of all, all of the dogs assigned to the extinction got 25-30 correct trials out of 30 possible trials in the acquisition phase, while every single dog in the reversal group got only 4 correct trials in this phase. This hardly seems to be possible by coincidence but the authors don’t offer an explanation of why the dogs were divided this way. (And I can’t think of one either!)

The researchers also stated that at the beginning of all training (both the acquisition phase and the experiment), the person performing the point cue attempted to gain eye contact with the dog and looked at the dog for the entirety of the training. I’m confused why this was done because staring at a dog can be threatening and stressful to the dog, and it’s not outside the realm of possibility that this could impact the stranger/owner effect since a staring stranger may be substantially more scary than a staring owner.

The other significant concern I had was the use of “correction” in the reversal learning experiment. If the dog chose the container towards which the human was pointing, the handler would jerk the dog’s leash and say “No,” and just verbally reprimand the dog after two leash jerk/verbal corrections. This type of correction is positive punishment and it’s a very ineffective and inefficient way to get a dog to learn. In fact, the average number of trials needed by dogs in this reversal group (both the owner group and the stranger group dogs) were higher than the average number of trials needed by dogs in the extinction group. Obviously, this could be a function of the task difficulty (perhaps extinction is easier to “learn” than reversal) but the higher number of trials could also have been the result of this confusing, inefficient training methodology.

Even though I have substantial qualms with the protocols of this research, because all dogs were treated similarly, I do think that this research provides evidence that the bond to an owner influences learning in some way. I thought the authors’ focus on an encompassing explanation of why owner group dogs learned extinction slower but reversal faster was perhaps misguided. It makes a lot of sense to me that dogs would have a very strong behavioral habit of going where their owner pointed due to the intermittent reinforcement previously theorized. I would hypothesize that owner group dogs learned reversal faster because it was a totally novel behavior and the owner/dog attachment facilitated that learning. I would be very interested to see this research question addressed by another group of researchers with more veterinary behaviorist oversight to see if these results can be replicated.

Journal Article: How Did Dogs Get to Understanding Humans?

Title: The Domestication of Social Cognition in Dogs

Authors: Brian Hare, Michelle Brown, Christina Williamson, Michael Tomasello

Published: November 2002 in Science

General overview:
These authors conducted four experiments to explore three hypotheses about how domestic dogs may have acquired their adept skill at using human social cues: 1) canids (wolves, foxes, coyotes, dogs and etc.) are adept at exploiting the behavior of both conspecifics (members of the same species) and other species due to hunting requirements of their diet. This hypothesis predicts that many canids would perform as well as dogs on tasks involving social cues from humans. 2) Domestic dogs have much more experience with humans and their social cues due to dogs/humans’ relative closeness from a very young age. This hypothesis would indicate that dog puppies of advancing age would performing increasingly well at tasks involving human social cues due to their cumulative knowledge of living with humans longer. 3) Dogs have undergone a selection pressure during domestication for specific skills involved with using human social cues. This hypothesis predicts that dogs and puppies (over a certain age) would perform equally well on tasks requiring human social cues and would outperform their nearest relative, wolves.

The authors conducted four experiments to explore canid skills in exploiting human social cues for food rewards (with control experiments to address olfactory food detection). In the first experiment, the researchers tested 11 dogs and 11 apes on the ability to correctly choose a container that was gazed at, pointed at and had a small marker placed atop. Dogs were significantly more skilled at this task, demonstrating that dogs are better at exploiting human social cues than humans’ nearest relative.

In the second experiment, 7 dogs and 7 human-reared wolves were tested on the ability to correctly choose a container with a single or combination of the following human social cues: gaze, point and/or tap. Dogs generally outperformed wolves, although the wolves did appear to understand a combination of the cues.

In the third experiment, 5 dogs and 5 human-reared wolves were individually shown food being hidden in a container and then later had to pick the container from memory. Dogs and wolves performed equally well in this experiment.

In the fourth and final experiment, the authors tested 32 dog puppies between the ages of 9 and 26 weeks. The puppies were tested on their ability to pick out a container based on a gaze and point or just a gaze by a human. Some puppies had been reared from a young age by humans while others had been raised in a kennel situation with limited human exposure. There was no difference between age or rearing type on either cue.

From the last three experiments, the authors conclude that their results suggest that dogs’ ability to exploit human social cues was due to selective pressure during the domestication process (hypothesis 3). Because puppies of all ages and human exposure type performed well on tasks using human social cues and while dogs and wolves performed well in the memory task (experiment 3), dogs outperformed wolves at social tasks, the authors found a significant social-cognitive difference between wolves and dogs that suggests an evolutionary explanation rather than the general social skill of canids (hypothesis 1) or a human exposure source (hypothesis 2).

My comments:

As you may have been able to tell, this article was chock full of interesting experiments and results. Science is a very prestigious journal with one of the highest impact factors of all academic journals. In other words, you don’t get published in Science unless you’ve done some pretty fascinating work!

Although their sample sizes are small (10 to 32 test subjects), these authors make a compelling argument to support the domestication theory of dogs’ ability to read human social skills. Of course, in order for this theory to be fully accepted, these experiments will need to be reproduced (and likely already have, since this research is 12 years old). Unfortunately, given the number of experiments these authors were explaining and the limited word count of Science, not a lot of space was given to elucidating the experimental conditions or even the subjects (except for the puppy experiment where ages were given, the only thing I know about the animals tested was their species). Of course, future researchers can always contact the corresponding author for this information if they’d like to replicate the science.

In my view, this research has very interesting implications for canine welfare. In many areas of the U.S., dogs are legally protected as property, with the exception that owners must provide adequate shelter, food, water and veterinary care. Basically, in our legal system, a dog is a box*.

However, if dogs are cognizant of human social skills, is it humane to treat a dog as a box*? After all, if you scream at a box, no harm is done. If you scream at a box*(i.e. a dog), and the dog feels stress from that social cue, has harm been done? Where and how does a creature’s cognitive abilities play into its welfare requirements?

(*that you can’t outright neglect or abuse)

These findings are super applicable for training purposes. Many common dog training methods involve pairing a human-given hand or verbal cue with a behavior (i.e. a sit) from the dog. This research suggests that this type of training is only possible through the selective pressure that gave dogs skilled at exploiting human social cues an evolutionary edge. Consider that in contrast to training a cat: the same hand/verbal cues may not be as meaningful to felines (who by all accounts never underwent the same domestication process as dogs) than our canines!