Recently, a new research paper was published in the Applied Animal Behavior Science entitled "Behavioral differences among breeds of domestic dogs: Current status of the science."
The study does not present new data, per se, but instead looks at the depth and breadth of canine behavior science over the past 50 years and provides a very detailed look at what we know about behavior differences among breeds, what we think we know about these differences, and opportunities for more research.
The study includes references more than 120 other scientific studies about canine behavior (several I've referenced on this blog before) to create a thorough, and well-rounded report. While I doubt the conclusions will really surprise too many readers of this blog, I think the information is very interesting throughout (and I now have a lot more reading material ahead of me).
Among the key findings based on the American Veterinary Society of Animal Behavior:
1) Most studies have found convincing evidence of differences between breeds and breed groups with respect to behavior
2) Mant of these studies are based on survey results -- and such studies are vulnerable to inaccurate reporting on a dog's behavior because the survey responder may be infuenced by cultural and media biases. Studies based on survey results reported larger differences in behavior among different breeds and breed groups than controlled studies.
3) Many of the studies also show very large within-breed behavior variations. This variation is due to genetic differences within breed, and individual learning history as it relates to environmental differences and specific contingencies that the individual dog has contacted throughout its lifetime.
4) Breeds are not equally represented in the research - -and specifically, some breeds are vastly overrepresented, making conclusions about the influence of breed on behavior difficult to generalize as a whole.
5) When breed differences have been identified in scientific literature, they do not typically match behavioral descriptions in breed standards which are largely unsubstantiated.
In my opinion, some other key findings worth noting:
1) The study indicates that modern breeds are not closely related to ancient breeds because of a loss of genetic diversity due to historical, cultural and geographic factors.
2) Breeds that were commonly targeted in the media, and politics for human-directed aggression (pit bulls, German Shepherds and Rotweilers), in scientific studies actually consistently scored low on stranger-directed aggression as breed groups.
3) There were significant differences in behavior within breeds. This is partciularly true in differences between individual dogs within a breed group were bred for show vs field work. I think this is particularly highlighted in this German Study in which German Shepherds from show lines and those from working lines showed to be genetically identifiably different even though they were the same breed of dog.
4) There is a very interesting section on dog-directed aggression that notes that different dog breeds vary somewhat in their social signaling. In particular, some physical characteristics (snout length, ear structure, reduced skull shape) may influence social signaling and how dogs react to each other.
5) Many breeds were differently ranked for dog-directed aggression, owner directed aggressiona and stranger-directed aggression -- which suggests that environmental stimuli, rather than breed alone, play a major role in the propensity to exhibit aggression.
6) Physical characteristics often influence problem-solving tasks. For instance, short-snouted (brachycephalic) breeds seem more likely to use their paws in manipulation tasks where as long-snouted (dolchocephalic) breeds rely less on their paws better allow them to manipulate objects in small spaces with their muzzles. Physical attributes like muzzle length may also impact a dog's sense of smell which may cause some breeds to be more or less likely to rely on olfactory sense for seeking.
7) A dog's age, and experience working with humans (often as a result of the function of a dog in its use by the human) have a significant impact on human-responsive tasks and ability to follow human cues.
I highly recommend anyone interested in this topic to read the entire study. I think it's an interesting study, and further confirms what experts have said for decades about the influences of canine temperament and behavior. Termperament and behavior is complex system based on a variety of factors including:Breed, Breeding (within breed), upbringing, how they are rewarded/punished, envirornment, history of human interactions (social cues) and that ancient history doesn't play a close role in the behavior we see today.
I think this information largely helps support the notion that the idea of "aggressive dogs" should be based on an individual dog's behavior, and not its breed or appearance. Due to all of the factors that go into shaping behavior, there is a significant differential in behavior and temperament even within specific breeds of dogs.
I think the importance of a dog's ability to read its human cues is an important part of why the National Canine Research Council's differential between a "resident dog" and "family dog" is so important and relevant when assessing major dog attacks.
For more reading:
The entire 13-page study: Behavioral Differences among breeds of domestic dogs: Current Status of the Science
Journal of the AVMA -- Co-Occurence of potentially preventable factors in 256 dog bite-related fatalities
Breed Differences in Canine Aggression -- KC Dog Blog
Factors Associated with Aggressive Responses in Pet Dogs -- KC Dog Blog