If you've ever had a faithful hound, you're already well aware that dogs can get antsy when you pay attention to other animals, and sometimes even other humans. Now, for the first time, researchers Christine Harris and Caroline Prouvost at the University of California, San Diego have shown that, yes, your puppy is prone to fits of jealousy.
"Our study suggests not only that dogs do engage in what appear to be jealous behaviors but also that they were seeking to break up the connection between the owner and a seeming rival," Harris said. "We can't really speak to the dogs' subjective experiences, of course, but it looks as though they were motivated to protect an important social relationship."
Harris and Prouvost worked with 36 dogs and a variety of objects, recording the results. First, the humans were to ignore the dogs and focus on two objects: a stuffed toy dog that barked and wagged its tail, and a plastic bucket, talking to and petting the objects as though they were actual dogs. The third object was a pop-up book, from which the humans were to read aloud.
The researchers then examined the videos, looking for examples of jealous behaviour: snapping at the objects and pushing them away to try and get closer to the human. With the stuffed dog test, 78 percent of the dogs pushed or touched the human while they were interacting with the toy, while only 42 percent did so with the bucket and 22 percent with the book.
Around 30 percent of the dogs tried to get in between the toy dog and the human, and 25 percent actually snapped at the toy; only one dog, however snapped at the bucket and the book. The researchers believe that the dogs were fooled by the toy dog: 86 percent smelled its backside, which is common canine greeting behaviour.
This is important because it demonstrates that jealousy does not necessarily require complex cognition -- a topic that has been the subject of debate among emotion researchers. The study suggests that jealousy has a more basic form that is used to protect social bonds.
"Many people have assumed that jealousy is a social construction of human beings -- or that it's an emotion specifically tied to sexual and romantic relationships," Harris said. "Our results challenge these ideas, showing that animals besides ourselves display strong distress whenever a rival usurps a loved one's affection."
You can find the full study, "Jealousy in Dogs", in the journal PLOS One.