A study led by researchers at the University of Cambridge provides a window into canine emotions, revealing why some golden retrievers are more fearful, energetic or aggressive than others.
The research, published today in the Proceedings of the National Academy of Sciences, is the first to show that specific genes linked to canine behaviour are also associated with traits like anxiety, depression, and intelligence in people.
The team analysed the genetic code of 1,300 golden retrievers and compared it with each dog's behavioural traits – assessed through a detailed owner questionnaire. This revealed genes underlying traits including trainability, energy levels, fear of strangers, and aggression towards other dogs.
By comparing their findings with a similar analysis in humans, the team discovered that twelve of the golden retriever genes they identified also underlie human behavioural traits and emotions.
"The findings are really striking – they provide strong evidence that humans and golden retrievers have shared genetic roots for their behaviour. The genes we identified frequently influence emotional states and behaviour in both species," said Dr Eleanor Raffan, a researcher in the University of Cambridge's Department of Physiology, Development and Neuroscience who led the study.
One gene, PTPN1, was linked to aggression towards other dogs in golden retrievers - and is also associated with intelligence and depression in humans.
Another gene variation, flagged up in golden retrievers that are fearful of other dogs, also influences whether humans tend to worry too long after embarrassment or are high educational achievers.
The team says the findings could help owners understand their pets' emotional worlds, and tailor training or care to suit their needs.
"These results show that genetics govern behaviour, making some dogs predisposed to finding the world stressful. If their life experiences compound this they might act in ways we interpret as bad behaviour, when really they're distressed," said Enoch Alex, a researcher in the University of Cambridge's Department of Physiology, Development and Neuroscience and first author of the report.
Insights for better training and care
The study showed that 'trainability' in golden retrievers is associated with a gene, ROMO1, that in humans is linked to intelligence and emotional sensitivity. This means owners should appreciate that there's an emotional component to training their dogs, say the researchers, in addition to rewarding desired behaviours.
The insights could also have implications for veterinary care: understanding that behaviour like fearfulness in a golden retriever, for example, is driven by a gene linked with human anxiety means that a medicine to reduce anxiety could help.
How genes drive behaviour and emotion
The dog genes identified by the team do not lead directly to any specific behaviour or emotion – rather, they influence behavioural regulation or broader emotional states. For example, dogs showing 'non-social fear' - that is, being scared of things like buses and hoovers - have a gene that in humans drives irritability, sensitivity, and 'seeing the doctor for nerves or anxiety.'
"If your golden retriever cowers behind the sofa every time the doorbell rings, perhaps you might have a bit more empathy if you know they're genetically driven to feel sensitive and anxious," said Dr Anna Morros-Nuevo, a researcher in the University of Cambridge's Department of Physiology, Development and Neuroscience who was also involved in the study.
"Dogs in our home share not only our physical environment, but may also share some of the psychological challenges associated with modern living. Our pets may be excellent models of some human psychiatric conditions associated with emotional disturbance," said Professor Daniel Mills, a specialist in problem animal behaviour at the University of Lincoln, who was also involved in the study.
Linking behaviour to underlying genes
The team used data on the behaviour of 1,300 dogs - aged between three and seven - involved in the Golden Retriever Lifetime Study, which has been run by the Morris Animal Foundation since 2012. Enrolled dog owners answer questionnaires about 73 different behaviours of their pet, which are then grouped to give scores in 14 categories that reliably predict various behavioural traits.
Using blood samples, the team searched the entire genome of each golden retriever for genetic markers that were more frequent in dogs with each of these 14 behavioural traits, compared to those without it. This allowed them to link specific regions of the genome with specific behavioural traits.
