We know that whales fall in love, horses feel pride, and primates can even become embarrassed and envious. And now it appears that dogs get jealous, too. A new study out of the University of Vienna is the first time scientists have observed and documented envy in a non-primate species, though people who own dogs may have already seen it in action.
The research team asked 14 trained dogs to “shake” in a series of experiments. To test for jealousy, the researchers put the dogs in a room alone, or put them in the company of another familiar dog (either an acquaintance or another dog from the same household). And while the researchers didn’t offer the dogs a bone, they did give one or the other of the dogs either sausage or bread when they wanted to reward the dogs for performing the task. When the hungry dogs realized they were doing the same work but not getting any food in return, they became jealous of their companion, who was getting fed.
In fact, the dogs who were denied treat would eventually stop shaking the researcher’s hand entirely, and would look away from the researcher and even scratch, yawn, and lick their mouths.
This study was based on previous experiments designed to test for “inequity aversion” in animals, a trait that’s important especially in driving dogs to co-operate (or so the theory goes in humans).
All of which means that, if a new baby or new lover arrives in your household, then don’t be surprised if your dog gets a little jealous.
Image: Boonsri Dickinson