The canine relationships in my house are friendly but complex. My young Collie mix, Jenny, regularly commandeers food and toys from my elderly Golden, Jack, taking them directly out of his mouth. He tolerates this with characteristic patience. This one-way flow of resources from Jack to Jenny might imply that she holds the higher rank in their mini-hierarchy.
Yet, when she greets him after an absence, she does so with classic submissive body language, licking him under the chin. And when he really cares about a particular toy, such as his beloved red ball, he protects it with a quiet growl that she immediately respects. How am I to interpret their social ranking—who is dominant and who is subordinate?
The question of how to use behavior to understand rank in dogs is not just of academic interest. Some approaches to training and managing canine aggression are constructed around theories about rank relationships between dogs and humans, theories that are based on beliefs about rank relationships between dogs. But because science hasn’t traditionally considered this particular aspect to be an interesting research area, the depth of our actual understanding of canine social hierarchies leaves much to be desired. However, “dog science” has begun to grow in recent years, becoming a newly respectable field producing more and more data, so that may be starting to change.
What We Don’t Know
The question of how dogs understand and assert rank has provided fodder for ferocious contention among dog trainers. The “dominance” theory of dog behavior holds that much of canine aggression is due to an attempt to assert a high rank (in other words, dominance) over a lower-ranking group member. Therefore, aggressive behavior may be reduced by a human display of behaviors associated with high rank in dogs (or their close relatives, wolves).
For example, an owner might seek to reinforce her dominant status by ensuring that she passes through doors before her dog, eats before her dog and never loses a game of tug. This traditional approach is still practiced by many, yet is heatedly debated. Karen London, PhD, CAAB, CPDT, has referred to dominance as “the D-word,” playfully suggesting that it is too offensive a concept to write about in polite company.
Dominance theory is not based on a scientific understanding of how to change animal behavior. Patricia McConnell, PhD, CAAB, called dominance “one of the most misused and misunderstood words in the English language, at least in relation to dog training.” Its practice can actually lead to increased aggression in dogs, potentially resulting in humans being bitten and dogs being surrendered to shelters, or even euthanized.
Science has not supported us in our quest to understand the relationship between canine rank and aggression. Social hierarchies have been studied extensively in wolves, both captive and wild, and in non-human primates, but rarely in dogs. Traditionally, researchers seem to have perceived Canis familiaris as tainted by human intervention— not a natural species and therefore not worthy of study. Domesticated species have traditionally been uninteresting to behavioral ecologists (scientists who study behavior and evolution), or their predecessors, ethologists.
Lack of data about how dogs understand and express rank and the charged environment around the use of rank in explaining dog behavior discourage a nuanced discussion of how often dogs have dominant-subordinate relationships with each other, and how dog social hierarchies are structured. These are important questions as research on canine behavior, once so sparse, begins to flourish.
What We Have Learned
The best way to answer questions about how dogs interact is to watch a lot of dog interactions. Behavioral ecologists at Utrecht University in the Netherlands did exactly that, recording the behavior of a group of 10 dogs over the course of two months. It was a young group, with only one adult, a two-year-old female Cairn Terrier. The rest were puppies and adolescents under 18 months. In fact, the three highest-ranking dogs were all juveniles: a six-month-old male Beagle, a one-year-old female Malinois and a five-month-old male Doberman.