Similar to us humans, dogs also differ individually in their temperament and behavior. Some of this variation is based on upbringing and experiences, but much of it is already genetically determined. An analysis of the genomes of over 1,300 golden retrievers now shows that many of the gene variations that influence traits such as trainability, fearfulness and aggression in dogs are also associated with various traits in humans. The results highlight how similar humans and dogs are and can help us better understand various traits of our pets.
Dog owners know from experience how individual their four-legged companions are – even within the same breed. For example, golden retrievers are generally considered good-natured and easy to train, but how capable each dog is of learning, how well it gets along with other dogs, how energetic and how skittish it is varies from animal to animal. Although education can promote or reduce certain behaviors, basic character traits remain unchangeable.
Like man, like dog
“Differences in emotional reactivity, sociability and other behavioral traits arise from complex interactions between genetic and environmental factors,” explains a team led by Enoch Alex from the University of Cambridge in the UK. In order to uncover the genetic factors, the researchers analyzed the genomes of 1,343 golden retrievers between the ages of three and seven years. In addition, they asked the owners to fill out a comprehensive questionnaire about the animal test participant’s characteristics and behavior.
In this way, the research team discovered numerous gene variations, each of which was associated with specific behaviors. Alex and his colleagues compared these results with similar analyzes in humans. They found extensive agreement: “We found significant associations in humans for psychiatric, temperament-related and cognitive traits in twelve of the 18 genes identified from the genome-wide association study in dogs,” the researchers report. “This showed a remarkable biological convergence.”
For example, a variation in the ASCC3 gene in dogs influenced how confidently they behaved towards other dogs. In humans, this gene has been linked to traits such as neuroticism, anxiety and sensitivity. A variation in a gene called ROMO1 promoted trainability in dogs. In humans, this variation is associated with intelligence and emotional sensitivity – an indication that training in dogs not only addresses their cognitive performance, but also has an emotional component.
Common genetic roots
“The results are truly remarkable – they provide strong evidence that humans and golden retrievers share common genetic roots for their behavior,” says Alex’s colleague Eleanor Raffan. “The genes we identified often influence the emotional states and behavior of both species.” From the researchers’ point of view, the study could help to gain more understanding of the emotional world of our pets. “Our results show that genetics control behavior and predispose some dogs to find the world stressful. If their life experiences compound this, they could behave in ways that we interpret as bad behavior, when in reality they are just distressed,” says Alex.
Impacts on veterinary care would also be conceivable. For example, if anxious behavior in dogs is promoted by the same genetic mechanisms as in humans, drugs developed for humans to treat anxiety could also help four-legged friends. Conversely, findings about dog psyche could possibly also be interesting for human psychology. “Dogs in our homes share not only our physical environment, but perhaps also some of the psychological challenges associated with modern life,” says co-author Daniel Mills from the University of Lincoln. “Our pets can therefore be excellent models for some human psychiatric diseases that are associated with emotional disorders.”
Source: Enoch Alex (University of Cambridge, UK) et al., Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.2421757122