Past surveys have shown that more than 80 per cent of dog owners report observing jealous behaviours in their dogs—vocalisations, agitated behaviour, pulling on a leash—when they give attention to other dogs.
Now new research out of New Zealand—and published in the journal Psychological Science—supports these observations and finds that dogs also exhibit jealous behaviours when they merely imagine that their owner is interacting with a potential rival, in this case, a highly realistic artificial dog.
Dogs appear to be one of the few species that might display jealous behaviours in ways similar to a human child showing jealousy when their mother gives affection to another child. In humans, jealousy is closely linked with self-awareness, which is one reason animal-cognition researchers are so interested in studying jealousy and other secondary emotions in animals.
To test how and when dogs display jealous behaviour, researchers at the University of Auckland presented 18 dogs with situations where they could imagine a social interaction between their human companion and either a realistic fake dog or a fleece cylinder. The fake dog served as a potential rival for attention while the cylinder served as a control.
In the experiment, the dogs observed the fake-dog rival positioned next to their owner. A barrier was then placed between the dog and the potential rival obscuring them from view. Despite blocking the line of sight, the dogs forcefully attempted to reach their owners when they appeared to stroke the rival fake dog behind the barrier. In a repeat experiment using a fleece cylinder rather than a fake dog, the dogs pulled on the lead with far less force.
Through their study, the team found that dogs showed three human-like signatures of jealous behaviour. Jealous behaviour emerged only when their owner interacted with a perceived social rival and not an inanimate object; occurred as a consequence of that interaction and not due to a potential rival’s mere presence; and emerged even for an out-of-sight interaction between their owner and a social rival.
“These results support claims that dogs display jealous behaviour,” lead author Amalia Bastos said. “They also provide the first evidence that dogs can mentally represent jealousy-inducing social interactions.
“Previous studies confounded jealous behaviour with play, interest, or aggression, because they never tested the dogs’ reactions to the owner and the social rival being present in the same room but not interacting.”