Over a 10-year period, we studied pair-wise play between adult dogs, between adult dogs and adolescents, and between puppy littermates. Our findings showed that the 50/50 rule simply did not apply. Dogs do not need to take turns being assertive in order for play to take place. However, this doesn’t mean that dogs never role-reverse during play, because they often do2 (e.g., Sage is in the top-dog position most of the time, but sometimes Sam gets to be top dog too). It just means that role reversals usually aren’t equally balanced.
Surprisingly, in some of the relationships we studied, individuals initiated play and preferred to play with others who were consistently assertive with them. For example, in a litter of mixedbreed puppies, one female, Pink, initiated play with a female littermate, Blue, more than twice as often as she initiated play with any of her other littermates (including another sister), even though Blue adopted the assertive role during play 100 percent of the time. Similarly, in our study of adult dogs, when the female German Shepherd, Safi, was playing, she was virtually always in the top-dog role. Despite this imbalance, other dogs sought Safi’s company and often invited her to play.
Sometimes people interrupt these interactions because they fear that rough play will escalate into an allout dogfight. However, in hundreds of hours of observations of play fighting between two dogs with established relationships, we have never witnessed a single escalation to real fighting. One of the authors hosted six to eight neighborhood dogs in her backyard every day for nine years, including two female German Shepherds, a male Husky, a male Husky mix and three mixed-breeds. Their play included all of the traditional “no-no’s” mentioned previously, but no dog ever received so much as a scratch. Other scientists report similar findings. The Hungarian ethologist Vilmos Csányi writes, “In some Hungarian animal rescue organizations, more than a hundred dogs … coexist peacefully.3”
Some people have the notion that rough play is practice for real fighting (or even killing). If this were the case, the dogs mentioned in this article did a great deal of practicing for fights that never occurred. Scientists originally hypothesized that animals play fight in order to enhance their combat skills, but recent research doesn’t support this assertion. Although we still do not completely understand why animals engage in social play, research suggests that animals play to help form social bonds, enhance cognitive development, exercise and/or practice coping skills for life’s unexpected situations. All of these benefits, if real, are important to our dogs.
Lately, there has been a lot of attention paid to the question: what is “safe” dog play? Although we recommend carefully monitoring play between dogs who are significantly different in size or age, or who do not know each other well, our studies have shown that dogs are very good at figuring out which dogs they want to play with and how to play well with their friends. Presumably, dogs are better than humans at speaking and understanding dog language. Perhaps it is time to humble ourselves and listen to them.
Safi, a female German Shepherd, and Osa, a male Golden Retriever mix, were best friends for many years. When they played, they snarled a lot, lips curled and teeth exposed. The snarls looked fierce, but they often preceded silly behaviors, like flopping on the ground. Also, when something in the environment suddenly interrupted their play, the dogs’ faces would instantly shift into neutral, alert expressions while they focused on whatever had stolen their attention. Then, as though on cue, Safi and Osa would put their scary faces back on, almost as if they were Halloween masks, and turn toward one another. Their expressions were so exaggerated and obviously fake that they always made us laugh. Some dogs can even be trained to show a snarl on command in a context that is otherwise perfectly friendly. These observations show that dogs can exhibit nasty faces voluntarily, just as we do when we are only pretending to be mean.