Posted Date: February 9, 2015
A new scientific study looks at whether dogs really experience jealousy. By Claudia Bensimoun
Most dog owners have seen their dogs showing what we consider to be signs of jealousy. In fact, dog trainers have long been using jealousy as a training tool by removing unresponsive dogs during training, allowing the dogs to watch their handlers working another dog close by. This appears to be a great motivator for many dogs. But do dogs really experience the emotion of jealousy? Researchers have argued about whether dogs can become jealous since this requires complex cognition.
In a 2014 University of California, San Diego study published in PLOS ONE, researchers Dr. Caroline Prouvost and Dr. Christine Harris addressed this topic. In this study, dog owners had to recount stories of when their dogs were "jealous." Most of the dog owners described similar characteristics of jealousy that their dogs had displayed in the past. When their dogs were jealous, they would engage in attention-seeking behaviors like pressing up against their owners, or going in between the owner and the person who was the object of the jealousy. They would bark, growl, whine and sometimes become aggressive. Some dog owners also claimed that their dogs felt guilty after being jealous, yet researchers say there is no empirical data that demonstrates a dogs guilt.
According to the new research paper in PLOS ONE, Dr. Harris and Dr. Prouvost modified a test used to assess jealousy in six-month-old babies. This is the first test used on dogs to measure jealousy. Thirty-six dogs participated in this study for three different tests. These dogs were videotaped inside their homes by the researchers who recorded the dog's owners ignoring their dogs and focusing on a stuffed, animated dog or jack-o-lantern pail. In this scenario, the dog owners had to treat the objects like real dogs. They petted and talked to them affectionately, pretending that they were real dogs. Next, the owners had to read a pop-up book that played melodies to the pretend dog. Two independent researchers then rated the videos for different forms of aggression and other behaviors that are associated with jealousy.
Researchers recorded aggressive behavior as possible expression of jealousy in dogs. Photo courtesy of Andrea Davis.
Methods for Testing
- All 36 dogs were less than 35 pounds or shorter than 15 inches. Researchers wanted small dogs in case there was the possibility of aggression after the dogs became jealous.
- All dog owners had to sign consent forms once researchers arrived at their homes to record testing. Researchers also inquired as to whether any dog would act aggressively if jealous, and, if so, the possibly aggressive dogs' owners were asked to remove the dogs from the testing situation.
- There were an equal number of male and female dogs, and a variety of breeds.
None of the dog owners were aware of what was being tested, and did not know what the hypothesis of the experiment was. In that way, they could not influence their dog's reactions during testing. All testing was videotaped. The owner then completed a questionnaire, and could interact freely between testing so that there would be a limited amount of carryover effects from the earlier tests. Each test took a minute.
The researchers used a stuffed dog that looked real, barked, whined and wagged its tail for eight seconds after a button was pressed. The participants were told to ignore their own dogs and to focus on the stuffed dog. They also had to do the same thing with a jack-o-lantern and a pop-up book that played songs.
The Behaviors Noted in Dogs
Two raters that were also unaware of the study's purpose coded the dog behaviors as being present, absent, and with a percentage of the behavior shown such as:
- Attention-seeking behaviors
Behaviors were also coded for the brief 30-second period after testing. Here four behaviors were seen.
- Aggression/snapping at the object
- Following the owner
- Observing the object
- Ignoring the object
Researchers coded for aggression because it is an emotion that is closely linked to jealousy in humans. They wanted to see whether the dogs would snap or bite the rival object (stuffed dog or book). They noted other signals of aggression such as lip curling and high-tail holding with ears forward, although the "ears forward" signal was later disregarded.
All in all, the most common indicator of jealousy in dogs was attention-seeking behavior. Dogs displayed this behavior by pushing against their owners, or trying to get in between the owner and the object. There were a few instances when dogs tried to make the object go away by pushing against the object.
The latest research regarding infants and jealousy suggests that when children are jealous, they will direct their attention towards their mother. Both Dr. Prouvost and Dr. Harris found that jealous dogs demonstrated the following behaviors:
- Watching the owner or handler with head turned and gaze directed at the object or person.
- Watching the rival or object of attention. Same as above.
- Turning away from the rival or object. Head and body of the jealous dogs were turned away.
30-Second Post-Interaction Period
When testing was done during this period (sessions between testing), the owner put the object down and moved away from it. The researchers found four behaviors were present during this stage.
- Aggression/snapping, which were both directed against the object.
- Jealous dogs would follow their owner or handler. They would also observe their owner.
- Dogs displaying jealousy would then sometimes ignore the subject.
The researchers in this case only noted the presence or absence of attention behaviors in dogs like either observing or ignoring an object. They also noted whether the dogs sniffed the hindquarters of the stuffed dog. Both researchers also tested attachment styles in jealous dogs, and how that linked to jealous behaviors.
Attachment Style Behaviors Found in Jealous Dogs
The researchers made up a form for the owners to complete regarding how attached their dog was, and noted all behaviors that were associated to different attachment behaviors in dogs. They also included behaviors that were linked to anxiety like a slightly lifted paw or a yawn, or of submission (ears flattened, tail down and licking).
The researchers found that one fourth of the dogs snapped at the stuffed object when they were jealous. There was no difference in the number of dogs that lowered their tails. All in all, during the post-interaction phase when the owner was no longer holding the object, a surprising 36% of dogs snapped and showed aggression at the stuffed dog. This was surprising to the researchers because the dogs owners believed their dogs to be non-aggressive in temperament prior to testing.
This study also demonstrated that dogs that were attention-seeking and very focused on their owners, while being jealous, were more likely to push against their owners and objects, or touch them. Most surprising was that these jealous dogs would try to go between both owner and object. This behavior is associated with jealousy in humans, and is hypothesized by researchers to distinguish this behavior from anger or other emotions.
The research also assumed that dogs did believe that the stuffed dog was a real dog because of the aggressive behaviors directed at it. A reviewer of the research mentioned that the dogs that did not act aggressively may have realized that the object was not a real dog. A high 86% of the tested dogs sniffed the hindquarters of the stuffed dog during testing. Both Dr. Prouvost and Dr. Harris believed that had the stuffed dog been a real dog, there could have been more aggression involved. With that said, the researchers concluded that the pattern of behaviors displayed by these dogs showed behaviors that were very similar to jealous behavior in humans. Only 13.8% of the dogs did not sniff the hindquarters of the stuffed dog. Researchers believe that this was because they were not in a jealous state, since they did not try to go between the owners and the object. Many of the dogs that did not snap showed other jealous behaviors like trying to get in between owner and object; 61.9% pushed against their owners, and 57.1% pushed against the stuffed dog.
This study proves that dogs, especially those that spend a lot of time with their owners in training, agility, hiking and doing fun activities, are sensitive to their environmental dynamics, and to the interactions happening around them. Our furry best friends will do whatever it takes to protect a relationship that they consider invaluable to them.
Researchers considered these results supportive of the theory that jealousy as seen in young children can be seen in dogs. According to the researchers, this suggests that dogs can become distressed when there is a rival for their affection.
So yes, dogs do feel jealousy. According to research in PLOS ONE, domestication may have given rise to this because of how strongly bonded we are with our dogs today. Researchers say that it could also be because dogs are able to track a human gaze or see what their owners are focusing on. The research paper also questions whether jealousy in dogs came about because animals need cooperation from other group members to survive.
Claudia Bensimoun is a freelance writer in West Palm Beach.