Tell Me About Your Dog! – Part 2

Continued from Part 1


Nerve has become a catch phrase for almost everything. Good nerve, bad nerve, weak nerve, strong nerve, thin nerve, thick nerve. Where do these terms come from? And more importantly, what do they mean? The nerve itself is nothing more than a fibrous long cell that transmits impulses from parts of the body to the central nervous system and back again. I don’t think anybody is talking about one dog actually having “thinner” nerve cells than another, that would be a bit hard to measure. Webster also refers to nerve as a “boldness or brazenness.” And even though that is a bit more useful, it still does not really address the uses of the term. I personally believe that all the talk about nerve came from conversationalizing a behavioral concept that many people using the term are not even familiar with. I will attempt to give a brief description of this concept before talking about a practical assessment of nerve.

The concept I am referring to is one that the behaviorist Ivan P. Pavlov developed to type temperament. He used a system to differentiate between four basic “types” of higher nervous system activity (This where the term nerve came from.) He based his terminology on a concept that leads back to Hippocrates (500 B.C.) where the temperament types were based on four different bodily fluids, namely blood (sanguine type), mucus (phlegm/phlegmatic type), bile (choler/choleric type), and black bile (melancholic type). That is just to explain where the names came from. Now the breakdown of what the types actually mean.

What does Pavlov mean by “higher nervous system activity?” The two basic types of nervous system processes are arousal (excitement) and inhibition (blocking). Both of these processes are necessary for an animal to adapt to its environment and to learn and perform skills and tasks in order to function. These processes take place in the cerebral cortex of the brain as physiological studies have shown. It is the strength of these processes as well as their balance and speed of mobility between the processes that gave Pavlov the separation criteria for his temperament typing.

Dogs who displayed weakly developed arousal and inhibition processes were categorized as “weak types.” The name for this type is the melancholic type. Since these dogs are identified by their weakness of nervous system processes they will never function properly in their environment. Any degree of difficulty when performing a task leads to failure. They generally show passive behavioral tendencies and weak reactions. Avoidance and flight tendencies are pronounced. They appear often inhibited, anxious, and unsure, which are results of this weakness of nervous system processes. They generally have low stimulus thresholds.

“Strong types” are split into three different separate types as well.

First there is the “strong, unbalanced arousable (excitable) type.” This type is referred to as the choleric type. In this type display very strongly developed a rousal (excitement) processes with weakly developed inhibition processes. They often appear unruly and out of control. They have aggressive tendencies, and are very active dogs. Their responses to commands and handsignals that trigger arousal (excitement) processes are very fast. But the accuracy of the performances of tasks is often poor, since inhibition (blocking) processes are weakly developed and arousal processes dominate them. In other words, they do not differentiate as clearly between tasks. The active defensive reaction is pronounced. These dogs appear irascible (easily angered or quick tempered). They have low stimulus thresholds.

Second there is the “strong, balanced, mobile type.” This type is called the sanguine type. The word balanced refers to a balance between strong arousal (excitement) and strong inhibition (blocking) processes. These types perform all tasks very fast and accurately. They rarely make mistakes and learn very quickly. If they have the right attributes for protection work they make excellent service and performance dogs. They generally have medium stimulation thresholds.

Third, there is the “strong, balanced sluggish type.” This type is called the phlegmatic type. They have strongly developed arousal (excitement) processes and strongly developed inhibition (blocking) processes and a good balance between the two. The designation sluggish refers to a slow mobility between the two processes. These dogs are generally described as calm. They work consistently but slowly. They require strong stimulation to stay motivated and require repetition of stimuli. Their performance potential is limited due to the slow mobility. They have high stimulus thresholds.

I hope this gives the reader a bit of an understanding of the basic temperament types that have lead to the term nerve. Naturally there are still differences within each type. Again I would like to stress that the more detailed an assessment is, the better.

Now that we know where the term nerve comes from, we have to examine what we should look at when discussing the nerve of a dog. One big misconception is once again the stimulus thresholds a dog exhibits. A low stimulus threshold does not make a dog weak nerved. But it is likely that such a dog is a more reactive than one with higher stimulation thresholds. But the reactions have to be assessed separately to determine the strength of the dog.

Another misinterpreted trait is the activity level vs. calmness of a dog. Calm and sometimes even passive dogs are often said to have good nerve. And while the calm type still is one of the strong types, they are certainly not the most desirable workers. The passive type is actually more often the weak type than not. To give a little more food for thought on that topic, I’d like to refer to the findings of the behaviorist Krushinsky during the training of “anti-tank dogs” during the war. Anti-tank-dogs were trained to run under tanks with a pack of explosives strapped to their backs and remain there until the explosives could be detonated. Putting aside the wasteful aspects of this use for dogs, it needs to be said that it was an extremely difficult task for dogs to perform. Aside from the distractions of battle noise, smell, and people everywhere which made it difficult to direct the dogs, they also had to overcome natural fear and inhibition to stay only a few feet away from the steel tracks of the tanks. So it only stands to reason that dogs which were required for this task were dogs who had especially strong nerves. But to quote Krushinsky “it is a mistake to expect to find these dogs among the calm and passive types, instead they were all very highly arousable (excitable) and very active.” This didn’t become apparent however until all the candidates who showed great results in training were also tested for their arousability (excitability) and activity level. They performed tests measuring ease of arousal and physical mobility. The results were very clear, the dogs who performed their tasks in a reliable, fast and precise manner under these extreme demands were all dogs who also displayed very high activity levels and low stimulus excitability.

So all the talk about nerve that I hear in discussions is quite vague and not very descriptive at all. People’s tastes regarding which of the temperament types (or nerve types) they prefer seems to play a large role in which adjective they put in front of the word nerve when it comes to describing a dog. Again, I feel that we need much more detail in our discussions if we want to get a true picture of the dog in question.


The word courage implies a willingness to face and withstand something that is recognized as potentially dangerous or harmful. I have to agree with Dr. F. Brunner by saying that this is a much too anthropomorphized description to be used when discussing dogs. Another description of courage is also a fearlessness. That comes much closer to being useful in our discussion about dogs. We should probably go even a bit further in the dissection of the word to ensure that misinterpretations are few. Not showing flight behavior is definitely a part of what we are trying to say when we call a dog courageous. I guess a high stimulus threshold for worry causing stimuli may cause the appearance of courage as well. It is a very dificult term to define as a useful dog training term. I would change the term altogether and try to express what we are trying to say with the word courage by giving a quantitative analysis of a dog’s tendency to show avoidance behavior (this may range from none to outright flight). I am again not alone with this idea. My friend Thomas Baumann has developed a similar rating system for his police dog character test. Naturally there are more parts to what we are trying to say with the word courage, but those have more to do with the level of prey drive, and the particular active responses a dog shows in situations. Because when we talk about courage, we expect the dog to do something, and not just not show fear, or not run away. These responses depend more on the active behaviors dogs display during work. More on those later.


I feel I have to mention the term boldness after discussing courage. Too often they are used as the same word. When people say courage there is the implication that some struggle or confrontation took place to test this trait. We get the image that the dog did something “in the face of danger.” Boldness is a different trait. I believe that it relates to a dog’s sense of exploration and curiosity. Many dogs in breeds that are simply incapable of doing protection work still display boldness. To borrow from “Star Trek” for a moment, “To boldly go where no one has gone before” sums the trait up fairly well. To describe a dog as bold he has to be inquisitive and be willing to check things out. He may even be unsure about objects and other things in his environment, but the inner desire to see what it is and check it out makes a dog bold. We can use this term without touching on the subject of how a dog may deal with confrontations. It implies a certain level of confidence, but moreso it describes an active sense of curiosity that allows him to explore his environment in a bold fashion and approach anything that peaks his interest.

Energy and Hyperactivity

These terms are kind of my own. I want to briefly describe what I mean by them. During the discussion of nerve I talked about activity levels in dogs. While during that discussion we were talking about specific arousal to stimuli, I’d like to mention here that excitement and arousal can also occur non-specifically. High-energy and hyper dogs often appear as if they have a lot of drive. In those cases I then ask myself, what drive is it? Upon closer examination I find that the dog’s energy is not directed at anything specific. The worst case scenario is a dog who is just hyper. Hyperness is the worst kind of undirected energy imaginable. At seminars I refer to these dogs as having Attention Deficit Disorder, because that is truly how they act. Hyperactive and completely unfocused. With careful manipulation we can harness this undirected energy and give it direction by channeling it into a drive. This will not happen on its own, it is something we have to do as trainers. It is important to recognize that these traits exist. They have to be understood and put into perspective in order to design correct training methodology for a particular dog.


This brings me to the conclusion of part one and two of this article. It was meant to deal with certain general concepts that are important in the assessment process of reading a dog. In part two I will deal with the actual responses to stimuli and drives as the working part of the assessment process. I hope you join me for that one as well.

Continued in Part 3

Armin Winkler

Armin Winkler has been the instructor at many schutzhund training seminars. He has been training schutzhund dogs since 1976 and is a USA member who lives in British Columbia. His English translation of Dr. Helmut Raiser’s Der Schutzhund is available from Armin Winkler Publishing, 3503 Lakeshaw Road, RR#7, Duncan, BC Canada V9L-4W4 or by phone (250) 746-8989.