A new study shows dogs can display jealous behaviour and can imagine their owner petting another dog even when they cannot see the interaction.
Researchers from left: Associate Professor Alex Taylor, Rebecca Hassall, Amalia Bastos, Patrick Neilands.
Dog owners have long reported behaviours such as vocalising, restlessness, or leash-pulling when their pet receives attention directed at another dog.
A University of Auckland study, published in Psychological Science, provides empirical support for those observations.
“Our research supports what many dog owners firmly believe — dogs exhibit jealous behaviour when their human companion interacts with a potential rival,” says lead author Amalia Bastos from the University’s School of Psychology.
The team set out to establish whether dogs can form mental representations of situations that trigger jealousy, similar to humans.
Dogs may show jealous responses resembling those of a human child when another receives affection from their caregiver.
Jealousy in humans links closely to self-awareness, which motivates animal-cognition researchers to investigate secondary emotions in nonhuman species.
To probe jealous behaviour, the researchers tested 18 dogs in scenarios where the animals either could or could not see their owner interacting with a realistic fake dog.
The experiment also included a social interaction between the human and a fleece cylinder as a control.
When the fake dog sat beside the owner, experimenters later placed a barrier that hid the interaction from the test dog.
Even without visual access, the dogs strained to reach their owners when the owners appeared to stroke the rival fake dog behind the screen.
When the owner interacted with the fleece cylinder instead, the dogs pulled on the lead with substantially less force.
The dogs pulled equally hard whether the fake rival was visible or hidden, and also when the rival was fully visible in the final trial.
This pattern indicates dogs reacted to the interaction itself, not merely to attempts to look behind the barrier.
Researchers identified three human-like signatures of jealous behaviour in the dogs.
First, jealous responses occurred only when the owner engaged with a perceived social rival, not with an inanimate object.
Second, the behaviour followed the interaction rather than arising from the rival’s mere presence.
Third, jealousy-like responses appeared even when the owner’s interaction with the rival took place out of sight.
“These results support claims that dogs display jealous behaviour and they also provide the first evidence that dogs can mentally represent jealousy-inducing social interactions,” says Ms Bastos.
“There is still plenty of work to do to establish the extent of the similarities between the minds of humans and other animals, especially in terms of understanding the nature of nonhuman animals’ emotional experiences.
It is too early to say whether dogs experience jealousy as we do, but it is now clear that they react to jealousy-inducing situations, even if these occur out-of-sight.”
The research team included Associate Professor Alex Taylor, Rebecca Hassall, Patrick Neilands and Byung Lim.
The study took place at the University’s Animal Minds Lab.