What can we learn from lateral (right or left) tail wagging in our dogs?

Perhaps you have read somewhere about a few studies conducted regarding what is called laterality which is defined as the predominance of one side of the body over the other. Laterality has been observed in many species among them in dogs.  Dogs do have preference as to which side of their body they use in certain circumstance, for example, when using their paws, gazing at people and sniffing.

Is laterality also present in how dogs wag their tails?  There were a couple of studies that looked into this:

Interpretations of Quaranta et al. 2007 “Asymmetric tail-wagging responses by dogs to different emotive stimuli” Current Biology, 17, R199-201. DOI:10.1016/j.cub.2007.02.008 and Siniscalchi et al. 2013 

“Seeing Left- or Right-Asymmetric Tail Wagging Produces Different Emotional Responses in Dogs.” Current Biology, 23, 2279–2282. DOI: 10.1016/j.cub.2013.09.027.

The Quadrant et al study, which was the first, concluded that there is asymmetrical tail wagging in dogs. They interpreted this data by claiming that right wags expressed positive emotions as in the dog being “happy” such as when the dog saw the owner.  Tail wags to the left meant, according to researchers, that the dog was afraid or in fear thus representing negative emotions.

The second study, consisted of showing the study’s dog videos or the silhouette of dogs wagging their tails. In this study researchers wanted to verify if dogs experienced different emotions depending on which side the dog they were viewing wag its tail.

Some questions that come to mind as a result of these studies findings:

1. Does the data (and methodology) used in the study support the observations of laterality and their intrinsic emotions?

2. How should we interpret the rest of the dog’s body and its communication when presented with these different stimuli?

3. Was there a clear consensus as to what the researchers meant by “lateral movement of the tail- the sway of the tail?”  What about dogs that lift their tails first and then sway one side or the other?

4. As you can appreciate, reaching a conclusion from observing a dog’s reaction to a particular stimulus such as a tail wag to the right or left to “knowing” what the dog is actually feeling: happy or positive emotions or sad or fearful hence negative emotions is a big leap of faith.

While most of us are “dying” to know more about dogs we must still tread very carefully when either formulating studies or interpreting the data from such studies.

I am left wondering if a simplistic claim or finding as in: right wag = happy, left wag= sad can really shed some light in understanding really complex issues such as how dogs relate (and feel) towards other dogs as well as other species: feline and humans?  What about establishing some co-relation with these two sets of emotions with complex neurological/brain functions?

As students of canine ethology and behavior, should we not also take a closer look as to the methodology employed and the findings of studies before we begin to jump with excitement at the possibility of having learned something new about our subject of interest?