Dog bite expert & animal behavior specialist

Richard H. Polsky, PhD, CDBC
Los Angeles, California

“Bringing the science of animal behavior to attorneys”

Dr. Richard Polsky - The Dog Expert

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Animal behavior expert analysis in dog bite lawsuits

The scientific discipline of animal behavior utilizes a comparative approach in the study of animal behavior.  While this approach may not be understood by non-academically trained dog bite experts, or appreciated by dog bite attorneys, it nevertheless is of value when making analysis of aggressive behavior in dogs. Below, I will illustrate how animal behavior expert analysis  can be applied to dog bite lawsuits.

There is a fairly large literature about descriptive studies of aggressive behavior in rodent species, and findings from this literature could be used to provide insights into the motivational analysis of dog aggression.  Rodents are a group living species which maintain territories (much like dogs) and many aspects of rodent behavior appear to be governed by the same internal and external stimuli which govern dog behavior.  Evolutionary speaking, rodents are not that far removed from canines, therefore one would expect similarities in the mechanisms which govern the behavior of each species.   Below, I summarize research on rat aggression that merits special attention because of the obvious parallels it has with aggressive behavioral responding in domestic dogs and the forensic analysis of dog bites.

A program of research on aggression in domestic rats was conducted by Carolyn Blanchard and Robert Blanchard in the 1970s and 80s at the University of Hawaii. These researchers analyzed overt patterns of aggression and the sequencing of aggression patterns in domestic rats maintained in semi-naturalistic conditions in a laboratory setting.  Their methodology consisted of creating a new colony of rats, and then observing the aggressive responding by colony members to the intrusion of an unfamiliar rat introduced into their colony.

One finding was that when a strange male rat was introduced as a intruder, it was usually the dominant male of the colony which defended the territory.  Significantly, the dominant male utilized an “offensive” style of aggressive behavior for this purpose.  Offensive aggression was characterized by inflicting bites to specific body locations of the intruder (usually the back), accompanied by other kinds of offensive actions such as chasing the intruder, crowding the intruder, standing over the intruder, and piloerection (as with dogs this makes the dominant male appear larger by raising of the hair on its back).  Offensive aggression differed from displays of “defensive” aggressive utilized by the intruder. Defensive actions displayed by the intruder consisted of behaviors such as fleeing, assuming an upright “boxing” posture, and turning on the back into a submissive position (much like dogs).  Bites from the intruder were specifically directed to the face and snout of the dominant male, which differed from the bites to the back of the intruder delivered by the dominant male.

  Implications for dog bite witness expert testimony

The Blanchard’s identified two types of aggressive patterns: an “offensive” and a “defensive” pattern.  Each differed in terms of the  behavioral elements displayed (as noted above), and in terms of the location to where where the bites were directed to the opponent.

We know that dogs live in social groups (usuallyas a member of the human family), and dogs maintain territories. Therefore, obvious parallels exist between the two species. Since the basic factors which control rat aggression are similar to the factors which control canine aggression (the effects of learning, genetics, brain function, physiology, etc.) then one would expect to find similar kinds of behavior for each species under similar circumstances.  Similar circumstances arise, for example, when an unfamiliar person or unfamiliar dog intrudes into the territory of an established group consisting of the dog and its human pack members.

Do dogs behave like rats and target one specific body location of the victim?  Do dogs displaying offensive type of aggression in the defense of their territory, target body locations on the dog bite victim different from dogs displaying defensive, fear-based aggression?  If one generalizes from the above-mentioned rat research, one would predict that the intruder would be bitten by the territorially offensive dog on the torso or extremities, rather than face.  In contrast, intruder dogs would be expected to show fear-based aggression and bite the face of the opponent. To date, dog bite experts have not reached definitive conclusions about this, although anecdotally, in many dog bite cases it appears that territorially aggressive dogs direct their bites to body areas other than the face, and defensive dogs, in contrast, often direct bites to the facial area of a human. Another interesting question which lacks clarity is whether defensive aggression is always characterized by a single bite, as opposed to the offensive style of aggression in which multiple bites are delivered.

Many canine behavioral experts use the terms of offensive and defensive aggression in a general sense to describe the behavior of an attacking dog.  Most however probably do not appreciate that these terms were first coined by the Blanchard’s in their rat research. In dog bite analysis, these descriptive terms may be useful provided that fairly detail behavioral descriptions of the attacking dog and the victim are available. Moreover, it may be wrong to describe a dogs aggressive behavior as being offensive or defensive, and then assume it fits a certain diagnostic category.  Instead, animal behavior  expert analysis tells us that similar patterns of aggression in dogs are likely to be part of different motivational systems.