Monday 11 August 2014

Dominance in Dogs - Does it exist and what does it mean?

12/8/14 Edits: I have added some things since this went live, to clarify some points I made poorly. Edits appear in italics.

Dominance continues to be an issue of great controversy amongst dog trainers, scientists, and enthusiasts. And little wonder, considering the sometimes inhumane and deeply misguided things people have done to dogs in the name of dominance. A vehement rejection of these practices has led to a wild swing away from dominance, and claims that dominance does not even exist in dogs. It is no small ask, but to truly investigate this issue, we need to put aside our preconceptions and ignore emotional connotations. Come with me on a journey of the science of dominance in domestic dogs, but leave everything you think you know at the door. 


What is dominance?

Before we go anywhere, we first need to know what people mean when they use this word. It has many meanings in different contexts, so let's be clear we are talking about an ecological context, or how animals interact with each other and their environment. Within the ecological context, we are referring specifically to social dominance, which is how individuals interact with each other in order to gain access to resources. Resources are anything that will help an animal survive. Resources are often limited, so an animal in a social group will sooner or later be in competition with others in their group for limited resources. Social living has many benefits when it comes to resources, so social animals need ways to figure out who gets access to resources and when, without getting into fights, which are dangerous. Inevitably, social animals that live together will have many such contests over resources. Dominance becomes stable where one individual is typically dominant over another in a variety of contexts. 

A further development of the dominance concept is to look at "formal dominance", which may be thought of as signals of dominance and submission that are one-sided. These allow animals to avoid aggression in contests and 'negotiate' who will defer to whom. Deference is an important concept, here. The subordinate individual will defer to the dominant animal, and thus, dominance is more often supplied by the subordinate individual, not enforced by the dominant individual. This is important to remember! Trainers that say they are enforcing their dominance over a dog probably don't really understand what it is. Some signals of formal dominance have been proposed in dogs in play and in the presence of resources

Formal dominance signals are one-sided. One dog directs them towards another, but not the other way around. Image 
A dominance construct is most valuable when the dominant animal in any given situation is predictable before there is a contest and an outcome. So, while we might talk about dominance signals and interactions, what we are especially interested in is how these play out in multiple scenarios with different resources, and whether we can predict the outcomes of dominance interactions based on previous interactions or current signals - in other words, dominance relationships. This article will therefore emphasise predictors of dominance, and social groups where there are clear dominance relationships. This does not always occur! Dogs are social acrobats, and can find many paths to group harmony. Don't undersell them by assuming they are on a path without checking if it's the one they are actually on. 


Does dominance exist in domestic dogs' interactions with other dogs?

Yes. The scientific literature is actually quite clear on this point. Studies find that at least between two dogs in situations where they are both exposed to a resource, such as food, one dog will typically win out, usually without violence. This is an evolutionarily stable strategy, and is widespread in social species of all kinds. Check the references listed at the bottom of this post for more details.


Is there a social hierarchy in dogs?

Stable dominance relationships should lead to a linear or almost linear hierarchy. A linear hierarchy is where Dog A is dominant over Dog B, Dog B is dominant over Dog C, and Dog A is dominant over Dog C. A non-linear hierarchy is usually seen in triads. So, Dog A might be dominant over Dog B, Dog B is dominant over Dog C, but Dog C is dominant over Dog A. Furthermore, if there are several individuals in the group, there may be very few dominance interactions between some individuals and far more between others. Imagine that Dog E is 4 dogs from the most dominant dog, Dog A. If Dog A is anywhere near a valued resource, Dog E may be staying well out of the way. It has been argued that dogs may have dominance interactions, but not form a linear hierarchy because in some cases individuals may not interact with each other much at all, and in others, individuals may interact frequently, but no dominant animal is established. Scott and Fuller found in the 60s that some dogs did not establish a dominant and subordinate relationship when in contest with another dog. However, the first study examined a group of male, neutered dogs with no scarce resources, and did no tests for linearity in behaviours. The second established dominance soley through contest over a meaty bone, ignoring formal dominance signals. It may be that these are not good representatives of dog society. Another researcher found that there was little parental behaviour in free-ranging dogs, and no social hierarchy



Social hierarchies come in different types. Image

Other researchers have found evidence for linear hierarchies in domestic dogs. Hierarchies were determined in small numbers of feral dogs in West Bengal (see references to Pal), although it is unclear whether behaviours used to investigate dominance and submission in these studies were asymmetrical like the formal dominance signals discussed earlier. A recent study of 27 free-ranging dogs in Italy examined which behaviours were performed towards which dogs and found that a suite of agonistic (e.g. threat signals, chasing, growling, snarling, etc.) behaviours and submissive (e.g. looking away, flattening ears, tail and head down, crouching, etc.) behaviours were one-sided and their pattern of occurrence within the group was linear. This means that they found behaviours that were good indicators of dominance and submission, predicted which dogs would defer to whom and which dogs would win contests, and this resulted in a linear hierarchy. Another recent study in dogs at a dog daycare centre also found that submissive and agonistic behaviours revealed a linear dominance hierarchy, and a similar study that is yet to be published in full also found a linear dominance hierarchy by the same means, and identified active submissive postures (crouched, on back) and licking muzzle as the best indicators of dominance. 

The take home message here is that linear hierarchies can exist in dogs, but not necessarily must. Dogs in our homes may or may not form a linear hierarchy. Keep in mind one-sidedness. Studies that have found linearity used careful collection and analysis of data. This was not arbitrary, so beware applying it arbitrarily to your own situation. 


But, wasn't dominance in dogs originally extrapolated from studies on captive wolves, which were later found to be flawed?

Dominance in wolves is alive and well. Image
Yes. Which does not mean dominance does not occur in dogs. It means that the original studies in wolves a) should not have been based on artificial groups in captivity where stress may have heightened conflict, and b) should not have been applied to dogs. Data can actually be collected on dog social groups. And where that data has been collected, dominance exists, and social hierarchies are often recorded. To be absolutely clear about the wolf situation, wolves certainly do have social dominance. It is just more a factor of age and experience than the exchange of dominance and submission signals - although, age is a factor in dogs as well, with older dogs usually being more dominant. Some canine researchers argue that dominance in dogs is actually quite similar to dominance in wolves based purely on data and behaviours that indicate dominance. 


Does social dominance apply in our homes where resources are plentiful?

The work by Bradshaw et al. and Trisko suggests that it probably depends to some extent on the individuals that make up the group, who will in turn dictate the unique dynamics of that group. Resources aplenty may reduce or remove a lot of the pressure on dogs to form hierarchies. But, dogs are opportunistic by nature. They don't necessarily know that resources are plentiful, or care. There are also situations in homes where resources may not be plentiful. Proximity to and attention from an attachment figure (e.g. owner), high value food like bones, food that is dropped on the floor accidentally are all likely to be in limited supply, and some dogs may just never feel that their resources are safe. That may be because it's not (e.g. humans or other dogs regularly take them), or it may be because they live in a generally unpredictable environment, or it could just be that is who they are. It is not necessarily because a leader in the group has not stepped forward to tell them when they can and can't have something.


Does dominance play a role in interactions between dogs and humans?

It is sometimes argued that the concept of dominance in the dog-human relationship may well do more harm than good. It is also sometimes argued that dogs obviously know humans are not dogs, and they do treat humans differently to dogs, so perhaps do not consider them as part of their social group. My research group published a review paper in 2012 that makes the point that dogs use dog language to try to communicate with people, just as people use people language to try to communicate with dogs. If dogs are using their own social language to communicate with us, is it reasonable to assume that they view us as social objects? If they view us as social objects, could they consider us potential competitors in some situations? Considering resource guarding can certainly be directed towards humans, maybe so. 

This is not to draw a line between resource guarding and dominance. There are many reasons why a dog may resource guard and it is not considered a good indicator of dominance. Studies found submission the strongest indicator, followed by agonistic and dominant behaviours or postures. Remember that to establish a rank, there needs to be one-sidedness in multiple scenarios. If a dog still greets you with lots of submission, the fact that they also resource guard against you simply means that it's probably not because they think they are socially dominant. 


Does dominance play a role in dog training?

This is a really key question, and not easy to answer. In general training, it probably has little bearing. However, owner-directed aggression is not uncommon, and is frequently assessed as caused by social conflict between dog and human, or possession aggression. Many dogs may exclusively display submissive signals towards humans and never present a problem on this front. Many people almost instinctively instigate something like Plenty In Life Is Free (PILIF), Nothing In Life Is Free (NILIF), Learn to Earn, Say Please, or variations thereof. These protocols do many things (check my post on NILIF for details), but one key thing is they train a dog to defer to humans over resources. A dog learns that to get what they desire, they must first follow the directions of the human. This may be quite protective against social conflict between human and dog. For those dogs that do display dominant signals towards humans, it is critical to assess why before attempting a treatment. Dominance is not simply all owner-directed aggression, and a dog may try to control a situation that distresses them by directing the same agonistic behaviours and signals that they may use in dominance interactions with other dogs towards humans that are distressing them. Treating a dog that does not feel safe with a deference protocol is unlikely to make it feel safe. Safety trumps everything, including dominance and dominance hierarchies, and therefore must be considered first and foremost in any behavioural problem. Furthermore, where dominance signals and threats are being directed towards a human and there is an absence of submissive signals in any context, it should absolutely not be treated in any way that is even remotely confrontational, and that includes how you might apply a deference protocol. A multi-pronged and non-confrontational treatment tailored by a behaviourist is recommended. 


Dominance and leadership - what it ain't

It is most important to stress that dominance and leadership in dog society is not typically aggressive, and submissive behaviours are better predictors of social rank than dominance or aggressive behaviours. Leadership is not demanded by a dominant member, but maintained by subordinates WANTING to be close to leaders and therefore following them. Dominance interactions are often a very subtle exchange of signals that we as humans could not hope to copy, not least of all because we do not have things like mobile ears and tails that are important parts of this communication. A few general recommendations can be extracted from this literature exploration.

1) The clumsiness of human body language is not suited to the subtlety of dominance and submission signalling in dogs. Trying to talk dominance to your dog the way a dog would is likely to result in excessively strong signals to a dog, which may in turn be confusing, threatening, or obnoxious. This could in fact provoke aggression rather than reduce it. Alpha rolls, poking or kicking, making harsh noises, staring at dogs... all of these signals are over-bearing and intimidating to dogs. They will act submissive because you are threatening them and they don't understand why. They are trying to tell you that whatever you want, you can have it, just please don't hurt them. Or they may just retaliate and bite you.

Dominance is often given through submission rather than enforced by the dominant individual.

2) Dominance is not demanded or enforced so much as offered by a dog's own free will through submission. Dogs can be taught to habitually defer to humans through a deference protocol such as NILIF. It needn't be strict and should not be harsh. Routine rules like going through doors first, eating first, and insisting dogs stay behind you or below you are not necessary and oftentimes meaningless to dogs. Dogs are usually focused on resources that are important to them in the moment and how to get them rather than social status as an abstract concept. Unless they show you that these things are resources to them by attempting to secure and protect access to them, there is no need to pay any attention to them yourself. Even then, dominance can be taken neatly out of the picture in most cases by simply making access to resources happen when the dog does as you ask them to. Be careful not to confuse simple resources with concepts of dominance. A bed may put a dog higher and closer to you, and you might think it yours, but it's also very comfortable, and it smells like you, whom they want to be close to. That is what matters to them, not that it's yours. 

3) If you want to be a good leader for your dog, you should be the kind of person they want to be around. Being the kind of person that gives them clear instructions and makes it rewarding to follow those instructions will make you attractive to your dog. 

A final word - Is my dog dominant over me? Or my other dog? Or a dog at the park? Or the mailman?

I wrote this article because I was tired of attempting to explain over and over that actually, science has NOT debunked dominance in dogs, or dominance hierarchies, or dogs as pack animals, for that matter, although I didn't cover that one. Just because it is a poorly understood concept does not mean it has no value or that it should be discarded, and to discard it is to run against current scientific thinking. If we accept dominance in dogs, it does not mean that we have to therefore accept that we must dominate our dogs, or that rank reduction is sensible, or that our dogs are out to rule the household, if not, the world. On the contrary, we just need to understand what it's for - reducing conflict. This may leave you wondering whether there is an aspect of dominance to your own relationship with your dog, or your dog's relationships with other dogs. Here is a simple, practical guide. Please note that research in this area is lacking, and this could change in the future.

1. Remember there are dominance interactions and dominance relationships. Your dog may negotiate with others over resources using dominance and submission signals, yet not have a clear dominance relationship with those individuals. In other words, there may be plenty of peaceful give and take and no clearly dominant or subordinate individuals.
2. Submission is the best predictor of dominance, so if a dog is submissive towards you in greetings, and defers to you (looks to you for direction) around resources, your dog probably sees you as dominant in your relationship, even if it is aggressive towards you in other scenarios. Aggression does not equal dominance. 
3. Dominance interactions are defined by outcomes (who gets the resource), and should be thought of as a two-way negotiation towards a peaceful outcome. A dominance relationship is where that negotiation has been successfully made many times before, and barely needs to be made anymore. Negotiations should become quite subtle and non-aggressive, and may be barely detectable. If you have a dog that is routinely aggressive or threatening and shows dominance signals in several scenarios, and rarely shows submissive signals, the dog may perceive the dominance relationship as unstable, which is super stressful for the dog. This should be dealt with by a professional behaviourist. It is the exact situation where attempting to enforce dominance is dangerous, and fights between dogs can escalate. 

References

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Bauer, Erika B., and Barbara B. Smuts. "Cooperation and competition during dyadic play in domestic dogs, Canis familiaris.Animal Behaviour 73.3 (2007): 489-499.
Bradshaw, John WS, Emily J. Blackwell, and Rachel A. Casey. "Dominance in domestic dogs—useful construct or bad habit?." Journal of Veterinary Behavior: Clinical Applications and Research 4.3 (2009): 135-144.
Scott, John Paul, ed. Genetics and the Social Behavior of the Dog. University of Chicago Press, 1965.
Cafazzo, Simona, et al. "Dominance in relation to age, sex, and competitive contexts in a group of free-ranging domestic dogs." Behavioral Ecology 21.3 (2010): 443-455.
Trisko, R.K., 2011. Dominance, Egalitarianism and Friendship at a Dog Day Care Facility. PhD Thesis. University of Michigan.
van der Borg, J.A.M., Schilder, M.B.H., Vinke, C., 2012. Dominance and its Behavioural
Measures in Group Housed Domestic Dogs. Proceeding in Canine Science Forum 2012, Barcelona. 
Schilder, Matthijs BH, Claudia M. Vinke, and Joanne AM van der Borg. "Dominance in domestic dogs revisited: Useful habit and useful construct?"Journal of Veterinary Behavior: Clinical Applications and Research (2014).
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McGreevy, Paul D., et al. "An overview of the dog–human dyad and ethograms within it.Journal of Veterinary Behavior: Clinical Applications and Research7.2 (2012): 103-117.
Fatjo, Jaume, et al. "Analysis of 1040 cases of canine aggression in a referral practice in Spain." Journal of Veterinary Behavior: Clinical Applications and Research 2.5 (2007): 158-165.
Bonanni, Roberto, et al. "Effect of affiliative and agonistic relationships on leadership behaviour in free-ranging dogs." Animal Behaviour 79.5 (2010): 981-991.
Herron, Meghan E., Frances S. Shofer, and Ilana R. Reisner. "Survey of the use and outcome of confrontational and non-confrontational training methods in client-owned dogs showing undesired behaviors." Applied Animal Behaviour Science 117.1 (2009): 47-54.