There are two main processes at play in any situation. Primarily, there is the reaction to the environment, which is the behavior we typically observe. And secondly, there is the ability to control that reaction. These two processes occur by different mechanisms in the brain, referred to as bottom-up (reaction to the environment) and top-down (the decision regarding whether or not to react to that environmental stimulus). These two processes are controlled by different neural processes, each which involves a different neurotransmitter, dopamine or serotonin. I’m not going to focus on details of neurobiology here, however, the concept that these processes occur via different mechanisms is important.
First we’ll look at response to the environment. Like us, our dogs react to environmental stimuli in different ways. The extent of their reactions is often environmentally determined, based on past experiences and learned behaviors. However, genetics also plays a large role in how the reaction is externalized. We have selected dogs for their specific responses to the environment in order to be able to best utilize their innate abilities to our advantage. All dogs are reactive, but they differ in the degree to which they react and in the behavior that is externalized as that reaction. For example, if a threat of danger is sensed in my house, several reactions occur. The golden retriever runs to the door to find out if the visitor might want to throw a ball, the beagle barks threateningly from a distance, and the kuvasz faces the threat with the intent to kill if necessary.
However, the factor that we often neglect to take into consideration is the dog’s top down control. As with people, dogs differ in their ability to control their reaction to their environment. Some dogs think through a situation before responding to it, while others respond instinctively and immediately. Again, selective breeding has produced extremes of these behaviors in different breeds. Dogs that are commonly used for police work, for instance, have been selected to react to a situation, almost without question. I think this is the “shoot first, ask questions later” type of response that is necessary in situations such as many of those faced by law enforcement. I’m not saying that police dogs don’t think, just that they respond to a situation when it arises, no questions asked. As a policeman, you want a partner that will respond to a situation, not one that takes in the entire surroundings and takes a few minutes to determine whether or not he should take action. Those dogs are trained to respond in a certain manner, usually with controlled aggression, but that response is under the control of the handler. On the other hand, dogs acting as guardians of flocks or herds of animals that are expected to work on their own, without a human for direction, have a very different control over their reactivity. Dogs such as the kuvasz, although considered extremely aggressive, might exhibit better response inhibition. My thoughts are that these dogs are working independently to protect their herd. Selection of dogs to perform this job has developed dogs with an ability to assess the threat, weigh the pros and cons of their actions, and then respond appropriately. This is great for an independent guardian, but not for a partner in law enforcement. Then there are those dogs that have great response inhibition and also very low reactivity to the environment. The world could collapse around these dogs and, well, they just wouldn’t get off the couch. That’s OK too, just another behavior we’ve selected in our best friend.
In my opinion, the word “reactivity” refers to a combination of both top-down and bottom-up mechanisms. Often the more important behavior in reactivity is not the actual reaction (i.e. bottom-up), but the top-down mechanism: the ability to decide how to deal with that stimulus. Research in attention deficit hyperactivity disorder has shown that there is a deficit in some people in their ability to suppress a response to a predicted stimulus, called response inhibition. I’m sure we’ve all known kids or adults, (hmmm, like myself) that fit this profile. We do things like interrupting conversations, blurting out inappropriate statements, and fidgeting. Basically, we lack the filter that other people have; the one that helps you to hold your tongue when you really want to speak your mind.
Both extremes exist in my household. On one extreme, our kuvasz exhibits extremely aggressive behavior in response to any perceived threat. However, she exhibits an amazing amount of self-control, or top-down functioning. She has complete awareness and control over any situation. If she didn’t, I’m quite sure we would have had at least one tragedy by now. The poor man applying siding to our house was lucky to have simply been firmly escorted backwards into his truck, as opposed to eviscerated where he stood. Although Kimba exhibits a high degree of aggression when she feels threatened, I do not consider her highly reactive, because she usually controls her reactions. On the other extreme, there’s my Golden Retriever, Quila. Like most Goldens, she’s the happiest dog that has ever lived. Her reaction to her environment is usually submission (to a threat) or extreme exuberance (to someone she knows). However, she has absolutely no top-down control! There appears to be not an ounce of her being that is able to control her responses to her environment. I admit that there could be training issues at either extreme, i.e. environmental factors at play. However, these behaviors are deep in the nature of their being. For instance, I worked extremely hard to be sure that Kimba’s aggressive tendencies were under control because they were threatening. I have not worked as hard on Quila’s top-down control because her behavior, although annoying sometimes, does not usually threaten others. That is unless, of course, she approaches another dog, like Kimba, with this same exuberance!
Another thing that we need to consider when looking at reactivity is the threshold level. This is a factor in top-down control. Some dogs might not react to the environment in a quiet subdued situation. However, if the surroundings change and the dog feels threatened or is excited by the presence of other dogs, it might react to a stimulus that it normally wouldn’t if under non-stressful conditions. Every dog has a threshold level and its response to being over that threshold differs in each individual. Some may just shut down and get stressed out, while others might go over the top and show behaviors we interpret as aggression, i.e. biting, snapping, and barking.
As dog trainers we need to recognize that these two behaviors, top-down and bottom-up, are separate and need to be considered differently. We need to be able to read the subtle cues that predict that a dog is going to react. Although, occasionally, this happens too fast in those dogs that react without any warning at all. Usually when we look back on a situation, we can think of subtle cues that we might have missed. Often we don’t even consider the reactivity level in a dog that exhibits a non-threatening reaction. We typically are only concerned about the behavior of dogs that exhibit aggression as their reaction. Dogs like my golden are rarely considered reactive, although, I suppose it’s all in the definition.
Aggressive dogs are another problem. What is aggression? We usually consider the act of biting, snapping, and basically, wanting to kill, as aggression. Aggressive behavior stems from two natural behaviors exhibited by our dogs’ wolf ancestor: killing prey (food) and defense of self and territory (self-preservation). We have recognized these two responses and selected these behaviors by breeding for our own advantage. For instance, terriers have been selected to exhibit the prey response: find and kill. Alternatively, defensive behaviors have been selected in breeds that have been used to guard our flocks and homes. These behaviors are responses to completely different stimuli. Consequently, different breeds can exhibit an aggressive response to different stimuli. Terriers will rarely exhibit aggression in response to fear, in fact they are rarely afraid of anything. A shepherd often exhibits fear aggression, they seem to be defensive. Yes, they do have a prey response also. They have probably been selected for both behaviors. It’s hard to find an example of a breed that exhibits just one or the other, most breeds probably have a little of both. However, I think we can see the prevalence of one or the other in most of our dogs.
So back to my initial question: What is a reactive dog? In my opinion, reactive dogs are dogs that lack self-control. A dangerous reactive dog, however, is one which lacks top-down control AND exhibits aggression in response to environmental stimuli. Even more dangerous, is when that dog has a low threshold, so almost any situation can set them off. I do believe that it is possible to have a healthy, happy reactive dog. This needs to be tackled from the standpoint of controlling the environment, i.e. recognizing the threshold level of the dog and always keeping it sub-threshold. You cannot learn new behaviors or self-control if you are over threshold. Think about any situation you’ve been in when you’ve finally had it, you broke the last straw! Are you in any mood to learn something? Probably not. When a dog is over-threshold like this, it is not the time to attempt to train him. I’ll try to post again on this subject later. But this is turning into a dissertation, so I’ll try to focus on my first subject. Sorry, another symptom of my ADHD: tangents. That’s a post for another day. I think I’ve taken up the limit of all blogdom.
So I think I’ll wrap it up with this thought: Reactive dogs exhibit low top-down control, regardless of whether or not they exhibit aggressiveness as their bottom-up response. Maybe we should treat all dogs with top-down issues the same. However, dogs that exhibit aggressive tendencies need to be kept sub-threshold and usually in separate classes with other dogs and handlers that all understand the rules and etiquette of dealing with dogs that exhibit aggression. I think the main point to take away is that if we fail to isolate these dogs in controlled environments and we, instead, allow them to enter into stressful situations, it is our responsibility as handlers when a situation ensues and someone gets hurt. Let’s work to keep all of our dogs sub-threshold and in a happy, healthy learning environment.
There is a wonderful discussion about how to deal with reactive dogs in agility on the Clean Run Yahoo! groups list today and yesterday (began Feb 17). If you’re not on the Yahoo! list, just sign up for a Yahoo! account, join the group, then you can access the discussion. Great ideas about how to keep your dog sub-threshold and much talk of separate classes for dogs with issues like these.
Actually as I write this I’m watching a show on Africanized bees. Scientists in