Source: David Hale Smith photo — Creative Commons License

I dropped by the office of a colleague of mine to pick up a book that she wanted me to read. Her office was different than most others in the university since she had an antique oak desk instead of the more modern university issue, and she insisted on tungsten lighting instead of the built-in florescent lights. However the most distinctive thing about her office was the fact that music was continually playing at a low volume from two compact speakers on her bookshelf. She claimed that the music helped to relieve the stress associated with teaching large classes and running an active research laboratory. Most typically the music was classical (she had a fondness for Vivaldi and Telemann), but sometimes it included soft rock, such as Air Supply or Phil Collins. However today the music was some kind of reggae.

I chuckled when I sat down and said, "I never could figure out your taste in music. I wouldn't think that reggae fits into the category of relaxing melodies."

She smiled and answered, "It's usually not, but variety is important in music. If you listen to only one genre it becomes boring and it no longer has a relaxing effect. So I have found that you have to change things up now and then."

"Well, I think that I now understand you a little bit better," I said, "I believe that you are not simply a professor, but you are the reincarnation of a dog. At least there is some new research which would suggest that you and dogs share the same musical tastes."

She cocked her head to the side and said simply "Explain!" So I did.

I told her that there are a number of pieces of research which have looked at the response that dogs have to music. This is not just a casual set of investigations since people who run kennels and dog shelters hope that if they can find music which is appealing and relaxing to dogs it can help to relieve their stress that they may feel when they are housed in an unfamiliar kennel. Generally speaking the experimental results show that classical music tends to have the most positive effects on dogs (click here for more about that). Hard rock and heavy metal seem to actually be upsetting to the dogs. So based on this data you might think that dog shelters would be piping in classical music all of the time. The problem is that research has also demonstrated that although classical music relaxes dogs, the effects are fairly short-term and after a few days or a week it seems to no longer have much of an effect. So a team of researchers from the University of Glasgow and the Scottish SPCA decided to investigate this issue further. Their research report was published in the journal Physiology and Behavior*.

The researchers tested 38 dogs housed in an animal shelter and the number of measures which was taken on each dog was quite extensive. In addition to monitoring each dog's behavior when they were exposed to various types of music, the investigators also strapped heart rate monitors on each of the animals in order to measure heart rate variability (which is generally understood to be a measure of the amount of stress that an individual is feeling). Furthermore regular urine samples were taken in order to measure the amount of the stress being produced by each dog. For six hours each day the dogs were exposed to music, not only classical music, but also soft rock, Motown, pop and reggae — a different style of music each day.

Perhaps the most significant finding was that any kind of music seems to have something of a relaxing effect on the dogs (remember no heavy metal or hard rock was used in this study, since previous work has shown that those sounds actually agitate the dogs). Behaviorally the dogs spend more time down and quietly standing rather than pacing when the music was on. There was no effect on the amount of barking during the music, however the dogs barked a lot more immediately after the music was turned off, as though they were complaining about its absence.

When the researchers looked at the heart rate variability measures, although all forms of music reduced the dogs' stress level, the largest stress reduction was found for soft rock and reggae. One of the most important findings was that by rotating through the various types of music over the five day period, they discovered that the stress reduction effects didn't disappear over time, the way it does if you are playing the same category of music all of the time.

In a press release University of Glasgow professor Neil Evans noted that not all dogs responded to the music to the same degree. He concluded that "Overall, the response to different genres was mixed highlighting the possibility that like humans, our canine friends have their own individual music preferences. That being said, reggae music and soft rock showed the highest positive changes in behavior."

Just as in humans, age seems to make a difference. The older dogs, eight years or more in age, showed little benefit from having music played suggesting that they much preferred quiet to a continued background of musical sound. I could empathize with that since when I was much younger I preferred having music going on all of the time and I had a bit of a love affair with various forms of rock music. However nowadays I am just as happy to surround myself with silence or the more gentle sounds of single voices in soft pop or country music.

In any event, the Scottish SPCA has found the results to be so promising that they are now installing music systems in several of their shelters in the hopes that rotating through various styles of music will help make the shelter experience more pleasant and less for the majority of their canine visitors.

My colleague smiled and asked, "So what kind of reggae worked best? Mento? Ska? Rocksteady? Dub? Rockers? Raggamuffin?…" At the sight of what must have been my very confused and uncomprehending expression she burst out and added "You really are an old dog aren't you?"

Stanley Coren is the author of many books including: Gods, Ghosts and Black Dogs; The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome

Copyright SC Psychological Enterprises Ltd. May not be reprinted or reposted without permission

* Data from: A. Bowman, Scottish SPCA, F.J. Dowell and N.P. Evans (2017).The effect of different genres of music on the stress levels of kennelled dogs. Physiology & Behavior, 171, 207–215, http://dx.doi.org/10.1016/j.physbeh.2017.01.024