By Dr. Becker
Have you ever wondered how much of your dog's behavior is nature (genetics) versus nurture (the environment and lifestyle you provide for him)? If so, you're not alone. It's a fascinating subject to all of us who love dogs, as well as scientists who study the influence of genetics on canine health and behavior.
One of the primary challenges of behavioral genetics studies is they require lots and lots of dogs as subjects. Securing such a large sample size with which to conduct standardized behavior testing is extremely expensive and time-consuming, so researchers are always looking for innovative workarounds.
Recently, a team of veterinary researchers in the U.K. decided to use a survey-based method to gather the data they needed from dog owners, since owners obviously have a significant amount of knowledge about their pets' behavior and personality traits.1 This approach, which in the U.S. is often called citizen science research, also has the advantage of eliminating issues that can arise in accurate data collection when dogs are behavior-tested in an environment that is unfamiliar to them.
Study Involved Almost 2,000 UK Labrador Retrievers
For their study, the U.K. researchers recruited 1,975 Labrador Retrievers registered with the UKC (United Kennel Club). They used questions from the Canine Behavioral Assessment Research and Questionnaire (C-BARQ) to measure a dozen different personality traits, including:
|Agitated when ignored||Fetching||Owner-directed aggression|
|Attention-seeking||Fear of humans and objects||Separation anxiety|
|Barking tendency||Fear of noises||Trainability|
|Excitability||Non-owner directed aggression||Unusual behavior|
A second questionnaire was used to compile data such as the age of each dog, gender and neuter status, coat color, housing, overall health, exercise and whether he or she was a gun dog, show dog or pet dog.
The researchers used the lineages of the dogs to gather genetic information, which involved 29 generations and nearly 30,000 individual dogs, as well as a different study using genomic methods and genetic markers. The research team looked for relationships between the 12 personality traits and aspects of the dogs' ancestries and genotypes.
Most Inherited Trait in Labrador Retrievers: Retrieving!
Interestingly, of the 12 traits, the two most often inherited turned out to be fetching and fear of noises. Aggression toward strangers and other dogs (but not owners) was also heritable. Also interesting is the potential role of the neurotransmitter dopamine in inherited behavior tendencies in dogs. According to the Genetics Society of America:
"Some of the variants associated with the personality traits were located near genes with known neurological functions. For example, dogs that were prone to agitation often carried a variant near the gene for tyrosine hydroxylase, which is involved in the synthesis of the neurotransmitter dopamine.
In humans, dopamine dysfunction is implicated in psychological conditions such as attention deficit-hyperactivity disorder, and some variants of the tyrosine hydroxylase gene are associated with the tendency to experience negative emotions and excitability — both traits related to impulsivity."2
Since this study used only U.K. Labrador Retrievers as its subjects, the authors caution that results for other dog breeds may differ. But these results do suggest the potential for a strong genetic component to dog personalities, similar to human personalities.
Are You a US Dog Parent Interested in Becoming a Citizen Scientist?
Adam Boyko, Ph.D., is a dog geneticist at Cornell University who created Embark, sort of the Cadillac of doggy DNA tests. For $199 you get a DNA swab test kit that generates a report revealing not only your dog's breed and ancestry, but also his or her risk for over 160 genetic diseases.
Brian Hare, Ph.D., is a canine cognition researcher at Duke University who owns Dognition, an online site that uses interactive games to assess the way your dog's mind works — how he thinks, learns and problem-solves. For $19 you get a one-time assessment and profile report. For a $79 annual charge, you also get monthly games and other goodies.
Boyko and Hare have formed a partnership to see if they can get 5,000 dogs in the U.S. signed up for both the Embark and Dognition products, which would allow them to conduct a large-scale canine behavioral genetics study.
"We know a lot more about the bodies of our dogs and how they can break down, more than what we know about their brains and behavior," Hare told the Washington Post. "The reason we do not know about genes involved with brain and behavioral problems is there has never been a large scale study combining behavioral and genetic data on thousands of dogs."3
Hare and Boyko believe one of the benefits of their collaboration will be helping dog parents better understand their pets. So-called "undesirable" behaviors are often rooted in a dog's genetics, and having knowledge of their pet's behavioral tendencies could help owners make adjustments to training, socialization and exercise habits to better meet their pet's needs. It might also help prospective pet parents make more informed choices when adopting a dog.
Establishing links between behavior, temperament and genetics in animals (including humans) is notoriously complicated and difficult. But some experts believe citizen science research projects are important because dogs evaluated in their own homes display more typical behaviors than dogs raised in laboratories.
Darwin's Dogs Is Another Citizen Science Research Project
Another citizen science research project currently underway to understand how specific genes control the behavior and health of our canine companions is Darwin's Dogs, led by Elinor K. Karlsson, Ph.D., a canine geneticist and assistant professor at the University of Massachusetts Medical School.
The Darwin's Dogs project is unique in that it doesn't focus on specific breeds or rely on DNA collected by scientists. Instead, Karlsson and her team are asking dog guardians to record their own observations of their pet's behavior and personality, and collect doggy DNA at home using mouth swabs provided by Darwin's Dogs.
Karlsson and her team collaborated with members of the International Association of Animal Behavior Consultants (IAABC) to create several short surveys to gather pet owner information about their dog's diet, behavior, personality and more. The Darwin's Dogs project is open to all dogs — purebreds and mixed breeds, and of this writing, enrollment is approaching 14,000 dogs.
Dog Behavior Is the Result of Nature (Genes) + Nurture (Environment)
Karlsson is combining genetic data from the dogs and looking for changes in DNA that relate to particular behaviors. She believes a dog's personality is shaped by both his life experiences and thousands of years of evolution.
"Have you ever known a dog who would retrieve the same ball over and over again, for hours on end?" asks Karlsson, writing for The Conversation. "Or just wouldn't stay out of the water? Or wasn't interested in balls, or water, but just wanted to follow her nose?"4
Canine behavior traits are the result of hundreds of generations of artificial selection by humans, according to Karlsson. Breeders select dogs to breed based on, among other things, certain desirable behaviors, and in doing so make the genetic changes responsible for those behaviors more common in their gene pool.
"It won't be easy to match up DNA with an obsession with tennis balls, for instance," says Karlsson. "Behavior is a complex trait that relies on many genes." Complex traits can be the result of tens or even hundreds of different genetic changes, and in addition, a dog's environment plays a major role and adds to the complexity.
"This is a huge effort, but could offer huge rewards," writes Karlsson. "By figuring out how a genetic change leads to a change in behavior, we can decipher neural pathways involved in psychiatric and neurological diseases shared between people and dogs.
We already know these include not just anxiety, but also PTSD, OCD, autism spectrum disorders, phobias, narcolepsia, epilepsy, dementia and Alzheimer's disease."
Karlsson and her colleagues are investigating both canine behaviors and diseases. Their theory is that by locating the genetic changes that led to complex behaviors (e.g., retrieving) and perhaps even personality characteristics, such as playfulness, they can learn more about how brains work.
How to Participate in Darwin's Dogs
The way the process works is that each participating dog guardian fills out a survey. After doing so, he or she will receive a kit to collect a small amount of their dog's saliva to be used for DNA analysis. There's no cost to the dog owner, and the researchers share any information they find. If you want to learn more or enroll your own dog in the Darwin's Dogs citizen science research project, you can do so here.