Recently, psychologist Dr. Christine Harris and her colleague, Caroline Prouvost, published the results of a study, confirming what many of us already suspected: dogs get jealous (see article here). By evaluating how dogs responded to their owners petting a fake dog and a jack-o-lantern pail, or reading from a pop up book complete with melodies. The dogs were least reactive to their owners reading a book out loud, a little less than half wanted their owners to ignore the pail, but a whopping 78% actively attempted to disrupt their owner’s friendly behavior towards a toy puppy by pushing or touching the owner. Some dogs went so far as to get in between the fake puppy and their owner, while others downright snapped at the offending ‘dog’. One dog out of 36 seemed to have “issues” and snapped at the book and pail as well. Yikes!
While this is certainly an interesting study, it has broader implications for what is jealousy all about. Not only that, but since we share this trait with other species, does that mean it is natural? What does this mean for us when considering jealous feelings in our own lives and relationships?
To answer these questions, let’s examine jealousy a bit more closely. Jealousy is frequently considered as a secondary emotion triggered in response to primary emotion like fear or anger. Regardless, jealousy is the feeling that someone is trying to take something you have. For instance, if you are a French angelfish or a titi monkey, someone might be trying to steal your mate. You might be wondering exactly how does a male titi monkey display his jealousy? He increases his aggression (vocally first, then physically) in direct proportion to the proximity of an outsider. Meaning the closer another male gets to his mate, the more distressed he becomes.
Given that a titi monkey couple forms a tight pair-bond and rely heavily on each other to raise their children, both have a lot to lose if their mate is filched by another. And this is not unusual. Frankly, anytime a strong bond is formed with a member of the opposite sex (or same sex), jealous behavior will emerge when an interloper is detected. In that sense, we can think about how jealousy may have evolved to protect social bonds from trespassers.
In species that don’t form strong romantic attachments, jealousy behavior over mates isn’t as frequent. Squirrel monkeys don’t really seem to care one way or the other and jealousy over mates is a non-issue. Food, on the other hand is another matter! Indeed, jealous behavior over the allocation of material resources is probably the next most common scenario where we see jealousy emerge. Sibling rivalry anyone?
If you think about it, as soon as you have a sibling, your parents’ time, energy, affection, and resources is divided up into smaller and smaller bits. Not to mention, just like in some human families, in many species there is some version of parents allocating resources differently among the kids. Yes, animal moms and dads can play favorites (hence all the jealousy!). In birds, one way they do this is by allocating hormones differentially during development. The end result is that one chick may be born larger and have a leg up on its siblings. A far more common strategy is for one sibling (usually the larger one) to just get rid of the competition. This is where we can all breathe a collective sigh of relief that we are human and not a pelican, an eagle, or a sand shark.
Whether it is time, affection, resources, or mates, we can see that, in other animals, jealous behavior is functional and purposeful. This brings up an important point and a critical difference between humans and other animals. Other animals respond to actual threats from potential mate thieves and to real differences in the allocation of time, affection, and resources. What we don’t see is jealousy in response to imaginary threats. A titi monkey will not wake up, having dreamt their partner was unfaithful and behave aggressively toward an imaginary intruder, or worse, its mate!
In some sense then, one could say that other animals are better at assessing situations and having an accurate view of what is happening. On top of that, animals are very busy accomplishing a lot of goals. They have to find food, survive, raise offspring, defend their territory, and maintain social relationships. They literally do not have the time to devote to unproductive activities not founded in an immediate reality. Not to mention that picking fights unnecessarily is extremely risky; someone could get injured.
We not only have the tendency to become jealous over imagined threats, but we also don’t seem to take into account the “cost” of certain behaviors. Spending your time watching, following, or checking up on your partner takes away from accomplishing your own goals. A healthy dose of suspicion seems understandable, whether it is in mountain baboons or ourselves. What doesn’t make sense is an all-consuming perception of constant threat. This is costly to one’s self and is damaging to relationship and becomes obvious when we recognize that jealousy often emerges as the third leading cause of non-accidental homicide.
That’s not to say not to say that we should ignore signs our relationships may be in danger. However, it pays to be a bit more like a titi monkey and evaluate whether something is actually happening or if it’s just insecurity wreaking havoc—not unlike the one hypersensitive dog who snapped at the pail! Speaking of which, the dogs clearly perceived the toy dog as a real threat. Most of the individuals ‘checked’ by sniffing the rear end of the toy dog and, after getting a good whiff, only 3 of them decided they had nothing to worry about.