Understanding Reactivity and Aggression in Dogs: Two Very Different Things
Apparently even experts have a hard time defining these terms
In this article:
What is reactivity? Examples of reactivity in dogs What is aggression? Examples of aggression in dogs
Historically, the term ‘aggression’ was used broadly to encompass various troublesome behaviours which can be problematic, such as barking, growling, lunging and snarling. Unfortunately, there is a lot of shame associated with having a dog who is labelled as ‘aggressive’. It’s not as loaded a term as an ‘angry dog’, but it can still make many dog parents feel bad.
The introduction of the term ‘reactivity’ aimed to address this issue by providing a more neutral, less judgy label for certain behaviours. The term ‘reactivity’ came about in part to relieve people’s shame about having an aggressive dog, which is why some of the first uses of the word involved discussing ‘lead reactivityopens in new tab’, which is essentially the same behaviour that has long been called ‘lead aggression’.
Reactivity refers to a response to a stimulus that is perceived as excessive or intense, while aggression traditionally involves behaviour with the intent to harm. Many people consider the term ‘reactive’ more appropriate for their dog, and are more comfortable using it. The fact is that dogs are either aggressive or reactive based on the descriptions above, but some dogs are accurately called both aggressive and reactive. Rather than focusing on labels, try to focus on addressing specific behaviours, because aggressive dog training and reactive dog training involve the same principles, skills and knowledge to be successful.
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What is reactivity?
Reactivity is frequently used to mean a response to a stimulus or a trigger that is over the top – usually based on big emotions, as we say these days. Part of the challenge of using the term ‘reactive’ is that it requires us to determine whether a dog’s response to something is excessive, and that depends on many variables: what caused the dog to react, what a normal response would look like, and so on.
The idea is that a reactive dog is one who responds to a stimulus in any way that is beyond what the situation calls for. That can include dogs who are so happy to see people or dogs, or a specific person or a dog (or even a toy), that they respond with excessive enthusiasm. It can also include dogs who get extremely aroused because of a negative emotional response when they see people or dogs (or even other animals, or if they hear certain sounds) and exhibit this response.
Examples of reactivity
Reactivity is a subjective construction because it means a response to a situation or a trigger that is more intense than expected by a typical dog. A dog who barks when the doorbell rings but stops and calmly greets the visitors would not generally be called reactive.
On the other hand, a dog who barks in response to the doorbell, body slams the door, spins barks whilst being inconsolable would reasonably be called reactive. These cases are not going to prompt much argument, but what about all the variation between these two extremes? It’s not easy to determine the line between behaviour that indicates reactivity, and typical canine behaviour involving some level of excitement.
What is aggression?
Aggression is historically used to indicate something about intention, because a common definition of aggression is behaviour with the intent to harm another individual. There are people who strongly disagree with the inclusion of intent as a part of the definition of aggression, because it is not possible to know for certain what a dog’s intention is. They prefer to look only at the behaviour without assigning any intent to the dog exhibiting the behaviour. It’s a fair argument that it’s more useful to describe what a dog does than to label them an aggressive dog.
Sometimes the definition is “any behaviour that causes harm to another individual or threatens to”. An issue with this definition is that a situation that causes harm could also just happen from an accident a dog has, such as falling off a surface, like the sofa, and unintentionally scratching someone on the way down or knocking someone over when greeting them exuberantly. Definitions can be so hard.
Agonistic behaviour
Aggression is just one of many types of behaviour that fall under the category of ‘agonistic behaviour’, which is any social behaviour that relates to fights or contests. For dogs, threats, displays and placating agonistic behaviours can actually reduce tension and lower the likelihood of aggression.
Over time, threats and displays have been lumped in with aggressive behaviour by dogs, which means that some behaviours that may actually prevent harm to one dog (or a person) by another dog have been included in the category of aggression. That leads to a weird situation in which many of the behaviours we describe as aggressive in dogs, are actually agonistic behaviours that have the intent to reduce conflict and to avoid fighting.
The truth: defining dog behaviour is complicated
Trying to define all behaviour precisely is problematic because we cannot generalise the truly complicated nature of behaviour. Definitions seek to simplify behaviour, however it is complicated to define and especially difficult when conflict and arousal are involved.
Reactivity alludes to the emotional aspects of what is going on, whilst ‘aggression’ refers to intent and to the possibility of injury. Many people find it frustrating that reactivity is so often confused with aggression, but that’s not surprising, given that the terms are not mutually exclusive. If you try to separate all dogs with certain types of undesirable behaviour into those who are aggressive, and those who are reactive, it’s impossible due to some overlap.
Some dogs, based on a general understanding of the terms, are both reactive and aggressive. Their emotions are over the top, and they may hurt someone. Others are just reactive. They are highly aroused and respond to other individuals in an intense way, but they never hurt, or try to hurt them.
Some dogs are aggressive, but not reactive. I’ve met dogs in this last category, though I think it is the rarest of the three groups. Those particular dogs may bite, and even cause a high level of damage, but they do so without any of the emotional arousal of typical scenarios. Usually, a dog who bites is either fearful – the most common emotional state of dogs who bite – frustrated, or in a high state of arousal.
I tend to recognise the term aggression in the same way that most pet parents do, to indicate any behaviour that infers that someone could get hurt by the teeth of their dog. That can include barking, growling, lunging, cold stares, tooth displays, nips, air snaps and bites.
What about body language associated with aggression and reactivity?
You can’t reliably distinguish aggression and reactivity based on body language alone. Both aggressive and reactive dogs can bark, lunge, growl, run, tuck their tales, leap around, cower, exhibit piloerection, pin their ears, show their teeth or give a fear grimace, among other behaviours. Aggression relates to intent and injury, but also to conflict resolution, and reactivity has to do with excessive arousal, but there can be overlap. Arousal is one cause of aggression, and a dog who is reacting excessively fearfully can behave in an aggressive manner.
Focus on the behaviour, less on the label
It would be my preference to focus on the behaviour and avoid labelling it. Labels have value for brevity and ease of communication, but so much is lost when we group large numbers of dogs into a small number of categories to define their behaviour. Clarification and context are always needed when we communicate using either of these terms. Rather than defining a dog as aggressive or reactive, I prefer to say, “This dog barks and lunges at unfamiliar people who she sees while on lead,” or “This dog bites people who reach for him.”
An emphasis on describing the behaviour rather than defining it avoids the confusion that can arise when the terms ‘aggressive’ and ‘reactive’ mean different things to different people.
Frequently asked questions
How can you train reactive or aggressive dogs?
All dogs, including those who are reactive and aggressive (or both), should be trained with positive reinforcement and patience. Punishment should never be used, especially as this contributes to fear and anxiety, which can trigger undesirable behaviour. Set dogs up for success, have reasonable goals and use management to keep everyone safe and relaxed.
When should I involve a professional for reactive or aggressive behaviour?
The knowledge and skills of qualified behaviourists are assets when working to improve the behaviour of any dog, but especially for teaching appropriate safety measures and supporting progress with aggressive and reactive dogs.
What should I do if my dog keeps biting me aggressively?
Seek professional help from a qualified canine behaviourist, and consult with your veterinarian to rule out medical causes of this behaviour. Be sure to see your medical doctor if you have any injuries.
