Because aggression is too complex an issue for one blog post, I will periodically return to it in the future to discuss different aspects. With this one, the focus is what motivates a dog to aggress.
We know that not every dog is aggressive, and the reason why some are and others not, in similar situations, is due to: mistakes made during the dog’s formidable imprinting and impressionable learning phases, which is between the ages of 3-16, or so, weeks, and/or; the dog’s present living environment, his Umwelt, and/or; neurochemical and hormonal imbalances the dog can be born with if mother dog was malnourished and stressed, or can show up at any time in a dog’s life.
When a dog aggresses, at that moment, the motivation is always to increase the distance to the trigger stimulus, or to eliminate it. In other words, whatever the dog perceives at the moment as a problem is too close, and he tries to make it/him/her disappear, in any way possible. Any way possible means: a growl on one end, or severe injury with the intent to kill on the extreme other end, or anything in between.
Here are some reasons why a dog would want to increase distance:
Fear of losing a possession. If a dog has something he values enough, or depends on for survival, he will defend it. In nature, a dog who has possession has ownership. And ownership is when something is given to him; surrendered. By the way, “rightful possession equals ownership” is a human rule also, and people that don’t obey it are called thieves. Because taking a possession away is not natural, it adds stress and confusion to fear when done forcefully, which intensifies aggressive displays. A possession can be anything, including a person or space. So be careful what you give your dog ownership over.
There are other fears that can trigger aggression, for example the fear to be hurt or harmed, or that offspring is harmed, and the fear to lose social belonging, which can be the reason a dog lashes out against a new group member.
With humans, aggression is an expression of anger; fear is expressed in avoidance and escape. Theoretically that may be so, but in reality it’s not that simple, especially regarding dogs, because they are under human control. Retreat is often prevented by the person in physical control. The dog is denied the option to flee, so he fights. If he gets attention for that - aggressive behaviors almost always changes the situation for the dog - aggression is reinforced and repeated. Any consequence maintains the aggressive behavior; it becomes operant conditioned and a functional coping skill.
Aggression to obtain a possession is not natural. As said, ownership should not be challenged. But dogs compete over resources before it becomes someone’s possession. If there is something one dog wants as much as another (dog or human), a dispute ensues and the one who ends up with the loot is the dominant one at that time.
Dominance is also when a dog controls access to something or someone he is claiming. Access control is controlling space – space around the object, subject or oneself. The dog who controls things and space feels in charge of it, and, in his mind, has the right to correct anyone who violates the rules he has set. Corrections are not intended to injure or eliminate, especially if directed against a social group member, but can nevertheless break delicate human skin. If the dog is successful and aggression keeps someone away from a resource, or out of his face, his behavior, again, is reinforced and becomes operant conditioned.
In a dog’s world, just as it is in ours, there is a distinction between familiar and unfamiliar; belonging and not belonging; in-group and strangers. A dog with a strong sense of privacy, and no leadership, will tell anybody not belonging to get lost. If prevented by barriers, such as a leash or fence, he becomes frustrated and reactive, aggressive displays intensify.
With all of the above, the intent is to increase distance to a perceived opponent or threat. With predation, it is the opposite: the intent is to decrease distance. The dog wants to catch the prey. That is why I don’t define predation as aggression, even so severe injuries and kills can result. A dog who has a strong prey drive combined with no or little bite inhibition, can bite repeatedly; slash and rip prey apart without consuming it. Orgy type kills are prey driven, and the result of pure instinct taking over.