Many dog breeds are noted for their personalities and behavioral traits, from the distinctive vocalizations of huskies to the herding of border collies. People have worked to identify the genes associated with many of these behaviors, taking advantage of the fact that dogs can interbreed. But that creates its own experimental challenges, as it can be difficult to separate some behaviors from physical traits distinctive to the breed—small dog breeds may seem more aggressive simply because they feel threatened more often.
To get around that, a team of researchers recently did the largest gene/behavior association study within a single dog breed. Taking advantage of a population of over 1,000 golden retrievers, they found a number of genes associated with behaviors within that breed. A high percentage of these genes turned out to correspond to regions of the human genome that have been associated with behavioral differences as well. But, in many cases, these associations have been with very different behaviors.
Gone to the dogs
The work, done by a team based largely at Cambridge University, utilized the Golden Retriever Lifetime Study, which involved over 3,000 owners of these dogs filling out annual surveys that included information on their dogs’ behavior. Over 1,000 of those owners also had blood samples obtained from their dogs and shipped in; the researchers used these samples to scan the dogs’ genomes for variants. Those were then compared to ratings of the dogs’ behavior on a range of issues, like fear or aggression directed toward strangers or other dogs.
Using the data, the researchers identified when different regions of the genome were frequently associated with specific variants. In total, 14 behavioral tendencies were examined, and 12 genomic regions were associated with specific behaviors, and another nine showed somewhat weaker associations. For many of these traits, it was difficult to find much because golden retrievers are notoriously friendly and mellow dogs, so they tended to score low on traits like aggression and fear.
That result was significant, as some of these same regions of the genome had been associated with very different behaviors in populations that were a mix of breeds. For example, two different regions associated with touch sensitivity in golden retrievers had been linked to a love of chasing and owner-directed aggression in a non-breed-specific study. That finding suggests that the studies were identifying genes that may be involved in setting the stage for behaviors, but were directed into specific outcomes by other genetic or environmental factors.
Well, it’s complicated
The same thing happened when the researchers looked at the regions that contain the equivalent genes in humans. “For example, the gene nearest the dog-directed aggression locus,” the authors write, “is associated in humans with intelligence, cognitive performance, educational attainment, and major depressive disorder.”
In total, the researchers identified a dozen sites that were associated with behavioral differences in both humans and dogs. Some of them made more sense than the example immediately above; for example, a genomic region associated with fear in dogs has had its human version linked to neuroticism and anxiety. Others get rather complex. A region near a gene called ROMO1 was linked to responding well to training in dogs. In humans, it has been associated with cognitive performance—which you can kind of see as connected—but also depression and irritability.
So, in short, the study identified a number of genes with a common function in behavior, likely conserved widely across mammals. But at the same time, it has generally failed to find a similar conservation of the specific behaviors that are being conserved, even across different dog breeds.
There are some caveats here. One is that the behavior ratings came from the dogs’ owners, which may have aspects of their own behavior that influence their interactions with their dogs or their interpretations of the dogs’ actions. In addition, the dogs may have been brought up in quite different environments. It’s hard to understand how this would create a spurious bias toward any particular genetic association, though a larger population should limit its impact.
The alternative is that many of these variants create what you might consider a point of flexibility for the nervous system. But other factors, either genetic or environmental, can bias that flexibility to specific destinations. And it’s important to note that, while we tend to think of “environmental factors” as things like chemical exposures, for behavior, they can just as easily be life experiences.
PNAS, 2025. DOI: 10.1073/pnas.2421757122 (About DOIs).
RC Auto, davvero ci sarà un aumento delle tasse sulle assicurazioni?