The emotional lives of dogs has become a hot topic as of late and made some big splashes in the media. In a recently published study, Christine Harris and Caroline Prouvost claim that dogs, like humans, experience jealousy.

The researchers tested pet dogs and their owners while their owners interacted with three different objects:  a toy dog that moved and made noise, a jack-o-lantern figure, and a children’s book that made noise.  Owners were instructed to interact with the objects and ignore their dogs.  When owners were interacting with the toy dog (compared to the other objects), their pets were more likely to touch them or the objects, move between the owner and object, and look more at the owner and object.  Dogs also “snapped” more at the animated toy dog than the other objects.  The authors state that these behaviors are “indicative of” jealously.

The report makes three fairly substantial, critical assumptions—two about the nature of emotion and one about how dogs behave with toys.

The first assumption is that behaviors map on to emotions in a specific way.  The idea here is that we can know the internal state of an individual based on his or her behavior.  In other words, if behavior X occurs, then emotion Y is present.  This is an intuitive idea that resonates with people.  But, the scientific evidence suggests this is not true. The problem is that there is a substantial amount of evidence that suggests this is not the case, even in humans who can tell us how they feel while they are behaving.  Overt behaviors don’t relate in specific ways to specific emotions.  Physiological patterns (e.g., what your heart is doing during an emotion) don’t relate in specific ways to specific emotions.  And so on.  Sometimes people (and rodents and dogs and monkeys) fight when they’re fearful and sometimes they run away.  Sometimes people smile when they’re happy, sometimes they make no facial behaviors at all, and sometimes people smile when they’re angry.   So particular behaviors aren’t “indicative of” particular emotions.

The second, related, assumption is that behaviors in animals are indicative of emotional states that are human-like.  This logical leap has been made for decades (particularly in studies of fear).  A freezing rat is said to be a fearful rat.  In actually, we have no way of knowing (yet) whether a freezing rat is experiencing human like fear at all.  Freezing is a fairly simple neurobiological reflex.  It’s hard to equate it with human experiences of emotion. Like for example, the experience you might have when you hear that a plane has crashed and your lover was on it, or the feeling you might have when you’re walking down a dark alley and hear heavy footsteps behind you.  Making the assumption that rat freezing is the same as one of those human experiences is a fairly large (and as I and others argue, problematic) logical leap.

The third assumption is that dogs’ behaviors differed with the toy dog because of emotion and not some other psychological state.  But there are a number of other possibilities.  For example, it’s possible that dogs were simply more interested in the toy dog because it was more complex or interesting or because it looked like a dog.  It’s possible that the dogs wished to play with it themselves, or were confused because it emulated a dog without being one.  Since the dogs were never tested with the objects and without the owner, or when the owner was not paying attention to the toy, none of these hypotheses can be excluded.

So, can Fido feel jealous? Possibly.  Humans have selectively breed dogs over thousands of years, creating modern day dog that is particularly responsive to human emotions, gestures, and eye-gaze.  Some of these capacities are unmatched even in our closest genetic relatives—the nonhuman primates.  Dogs also have fairly complex brains that may be capable of the computations needed for a complex socially oriented emotion like jealously.

But, based on this single study alone, the jealously jury is definitely still out.