September 15, 2015
"A student in training to become a dog behavior therapist and trainer sent me the following: I watched a TV program on lateralization in dogs. The narrator said right-pawed dogs use the left side of the brain and so are calmer, handle problems better, are more easily trained and are more likely to succeed in guide dog training than left-pawed dogs while left-pawed dogs use the right side of their brain so are more aggressive, fearful, have stronger fight or flight reactions and mostly fail in training to be guide dogs. So wouldn't a test for paw preference be the perfect way of choosing a puppy or older dog to be sure you got the temperament you want for a family pet, or a service dog or a working dog, by only taking right-pawed dogs?"
After much research, in the last 10 years there has been an increasing interest in lateralization in animals and how it relates to behavioral types.
This stems from a publication by Dr. Lisa Tomkins from the University of Sidney, Australia, suggesting dogs with a right-paw preference in the "Kong Test" are more trainable. (A Kong toy is stuffed with food and the percent of time in a four-hour test the dog held the toy with its right paw, left paw and both paws was measured.) The TV show the student had seen played up lateralization as a preferred method of picking a dog.
However, when Tomkins and her colleagues used a "first-step test" to determine left or right paw preference, the result was dogs that preferred either their right or left foot for the first step had equally good training success as guide dogs. Dogs could not be ambidextrous in the first step test because of always needing to lead with either the left or right front foot.
This research group also examined the direction of hair whorls, clockwise or counterclockwise, as predictive of training success. However, only hair whorls on the chest and to a lesser extent on the elbow were predictive of training success, and the predictions were in opposite directions at the two locations. Another research group showed no relation between lateralization and temperament in a 2013 study of 50 client dogs.
So what is going on here? First, much of the research on the relationship between paw preference and temperament is weak or flawed. One of the tests used only 10 dogs; another 14. There was no control for age or gender or breed or experience, all of which are known to have an influence on paw preference. All the results are in terms of correlations, which should never be construed to mean cause and effect.
For example, men who wear neckties at their job are more prone to get ulcers than those who wear T-shirts and no tie. It would be ridiculous to think this means neckties cause ulcers and T-shirts prevent them.
Another problem is the lack of standardization or agreement between the various measures of lateralization. Only the "Kong Test" has been shown to be at all repeatable, but it reportedly takes up to four hours to complete and the outcome can depend on the dog's motivation to get the food out of the toy.
Certainly you could not use it on pre-weaned puppies whose attention span is so short there could never be a four-hour span during which they showed enough interest for any kind of test. Far better to spend the time directly evaluating behavior of interest for the particular training program (e.g., fearfulness, aggressiveness, cooperativeness, etc.) the dog will undergo.
Another complicating variable is pups tend to show a right-paw bias, which changes as the dog matures. Most dogs become ambidextrous with about equal left or right bias in the remainder of the population, unlike humans, who show a preponderance of right-handers, a minority of lefties and only a small number of ambidextrous individuals.
All the research comparing male to female dogs for paw preference agreed females were predominately right-pawed and males predominately left-pawed. These studies made no attempt to relate the lateralization to temperament, however. Perhaps this is the basis of another myth — females are better hunters than males.
There is evidence a disproportionate number of men in prison are left-handed, fueling the leap that left-handedness is related to social deviation. I'll reiterate: correlation does not mean cause and effect. Many factors enter into making a social deviant, be it a dog or a person, with handedness doubtfully being one of them. There is no compelling evidence that suggests a disproportionate number of left-pawed dogs are bad dogs or that right-pawed dogs are all brilliant.
If there is a surrogate measure to predict qualities of temperament, though sounding very convenient, right-footedness is not it. At this point, it a misinterpretation of research, a myth in the making. If a breeder tells you his pups are all going to be great because both parents are right-pawed and all pups were tested and found to be right-pawed, get a tight grip on your wallet.
Yes, there could be a correlation between right-paw tendency and making good guide dogs. However, there are many other things that go into guide dog temperament such as age at weaning, genetics, training, etc. So do not depend on sensational TV or Internet "authorities" to make decisions for you. Read the research and grasp the truth before preaching mythology as gospel.
The primary goal of any reputable breeding program should be to improve the dogs' phenotype. For now, this can only be accomplished by having a thorough understanding of the ontogenetic, epigenetic and environmental contributions to phenotypic variations. This means the understanding and application of valid measures of phenotype.
Besides the genetic compatibility, performance to a standard, temperament quality, and quality of form and function of several generations of progenitors — both male and female — must be studied, evaluated and applied before breeding. Faults of any type, especially faults of temperament, must not be simply overlooked for convenience sake.
This philosophy must be followed whether you are acquiring a new dog, looking for a male to breed to your female or female to breed with your male. There is no shortcut available, footedness and hair whorl direction notwithstanding.
For solutions to your dog's behavior or training problems, contact Ed Bailey at firstname.lastname@example.org